android入门(2)

Jamin_Ye
86 阅读11分钟

本文已参加「新人创作礼」活动,一起开启掘金创作之路

  1. 数据存储
    1. sharePreferences: Android提供用来以最原生的方式对数据进行永久保存的方法,保存文件格式为xml,储存在data/data/包名/shared_prefs
      1. 获取sharePreferences对象
        1. getSharedPreferences(String name,int mode)
          • name 文件名
          • mode MODE_PRIVATE 被本应用读写
          • MODE_MULTI_PROCESS 跨应用读写
        2. getPerences(int mode)
      2. 获取SharedPreferences.Editor对象 edit()
      3. 向SharedPreferences.Editor对象添加数据 putBoolean(),putString(),putInt()
      4. 提交数据commit()
      5. 使用对象SharedPreferences类提供的getxx()方法获取数据
      package com.jamin.datastorage;

import android.content.Intent;
import android.content.SharedPreferences;
import android.os.Bundle;
import android.util.Log;
import android.view.View;
import android.widget.EditText;
import android.widget.Toast;

import androidx.appcompat.app.AppCompatActivity;

public class MainActivity extends AppCompatActivity {
private static final String account = "user";
private static final String pwd = "123456";

@Override
protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_main);
    final EditText editAccount = findViewById(R.id.account);
    final EditText editPwd = findViewById(R.id.pwd);
    final SharedPreferences sharedPreferences = getSharedPreferences("userInfo", MODE_PRIVATE);
    final SharedPreferences.Editor editor = sharedPreferences.edit();
    String user = sharedPreferences.getString("user", null);
    String password = sharedPreferences.getString("pwd", null);
    //    判断本地是否有数据
    if (user != null && pwd != null && user.equals(account) && password.equals(pwd)) {
    Intent intent = new Intent(MainActivity.this, Main2Activity.class);
    startActivity(intent);
    }

    findViewById(R.id.login)
        .setOnClickListener(
            new View.OnClickListener() {
            @Override
            public void onClick(View v) {
                String editAccountText = editAccount.getText().toString();
                String editPwdText = editPwd.getText().toString();
                //                验证
                if (editAccountText.equals(account) && editPwdText.equals(pwd)) {
                Toast.makeText(MainActivity.this, "login success", Toast.LENGTH_SHORT).show();
                //                  储存数据
                editor.putString("user", editAccountText);
                editor.putString("pwd", editPwdText);
                editor.commit();
                Intent intent = new Intent(MainActivity.this, Main2Activity.class);
                startActivity(intent);
                } else {
                Toast.makeText(MainActivity.this, "login failed", Toast.LENGTH_SHORT).show();
                Log.i("账号", editAccountText);
                Log.i("密码", editPwdText);
                editAccount.setText("");
                editPwd.setText("");
                }
            }
            });
}
}
    2. 内部存储 应用的data/data/包名/files/内部储存文件 
      package com.jamin.datastorage;

import android.os.Bundle;
import android.view.View;
import android.widget.Button;
import android.widget.EditText;
import android.widget.Toast;

import androidx.appcompat.app.AppCompatActivity;

import java.io.FileInputStream;
import java.io.FileNotFoundException;
import java.io.FileOutputStream;
import java.io.IOException;

/**
* @author Jamin 
*  @date 2019/10/11
* @desc 使用内部储存
* */
public class Main3Activity extends AppCompatActivity {
private FileOutputStream fos = null;
private FileInputStream fis = null;

private byte[] buffer = null;
private EditText editText2;

@Override
protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_main3);
    final EditText editText = findViewById(R.id.editText);
    editText2 = findViewById(R.id.editText2);
    //    保存文件
    findViewById(R.id.saveButton)
        .setOnClickListener(
            new View.OnClickListener() {
            @Override
            public void onClick(View v) {
                String content = editText.getText().toString();
                try {
                fos = openFileOutput("test", MODE_PRIVATE);
                fos.write(content.getBytes());
                fos.flush();
                } catch (FileNotFoundException e) {
                e.printStackTrace();
                } catch (IOException e) {
                e.printStackTrace();
                } finally {
                if (fos != null) {
                    try {
                    fos.close();
                    Toast.makeText(Main3Activity.this, "保存成功", Toast.LENGTH_SHORT).show();
                    } catch (IOException e) {
                    e.printStackTrace();
                    }
                }
                }
            }
            });

    Button cancelButton = findViewById(R.id.cancelButton);
    cancelButton.setOnClickListener(
        new View.OnClickListener() {
        @Override
        public void onClick(View v) {
            finish();
        }
        });
    // 打开保存的文件
    Button openButton = findViewById(R.id.openButton);
    openButton.setOnClickListener(
        new View.OnClickListener() {
        @Override
        public void onClick(View v) {
            try {
            fis = openFileInput("test");
            buffer = new byte[fis.available()];
            fis.read(buffer);
            } catch (FileNotFoundException e) {
            e.printStackTrace();
            } catch (IOException e) {
            e.printStackTrace();
            } finally {
            if (fis != null) {
                try {
                fis.close();
                String data = new String(buffer);
                editText2.setText(data);
                } catch (IOException e) {
                e.printStackTrace();
                }
            }
            }
        }
        });
}
}
    3. 使用外部存储 
      package com.jamin.datastorage;

import android.os.Bundle;
import android.os.Environment;
import android.view.View;
import android.widget.Button;
import android.widget.EditText;
import android.widget.Toast;

import androidx.appcompat.app.AppCompatActivity;

import java.io.File;
import java.io.FileInputStream;
import java.io.FileNotFoundException;
import java.io.FileOutputStream;
import java.io.IOException;

/**
* @author Jamin
* @date 2019/1012
* @desc 外部存储
*/
public class Main5Activity extends AppCompatActivity {
private EditText editText3;
private EditText editText4;
private Button saveButton;
private Button cancelButton;
private Button openButton;
private FileInputStream fis;
private FileOutputStream fos;
private byte[] buffer;

@Override
protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_main5);
    editText3 = findViewById(R.id.editText3);
    editText4 = findViewById(R.id.editText4);
    saveButton = findViewById(R.id.saveButton2);
    cancelButton = findViewById(R.id.cancelButton2);
    openButton = findViewById(R.id.openButton2);
    saveButton.setOnClickListener(
        new View.OnClickListener() {
        @Override
        public void onClick(View v) {
            String content = editText3.getText().toString();
            File file = new File(Environment.getExternalStorageDirectory(), "/test.txt");
            try {
            fos = new FileOutputStream(file);
            fos.write(content.getBytes());
            fos.flush();
            } catch (FileNotFoundException e) {
            e.printStackTrace();
            } catch (IOException e) {
            e.printStackTrace();
            } finally {
            if (fos != null) {
                try {
                fos.close();
                Toast.makeText(Main5Activity.this, "保存成功", Toast.LENGTH_SHORT).show();
                } catch (IOException e) {
                e.printStackTrace();
                }
            }
            }
        }
        });
    openButton.setOnClickListener(
        new View.OnClickListener() {
        @Override
        public void onClick(View v) {
            try {
            fis = new FileInputStream(Environment.getExternalStorageDirectory() + "/test.txt");
            buffer = new byte[fis.available()];
            fis.read(buffer);
            } catch (FileNotFoundException e) {
            e.printStackTrace();
            } catch (IOException e) {
            e.printStackTrace();
            } finally {
            if (fis != null) {
                try {
                fis.close();
                String content = new String(buffer);
                editText4.setText(content);
                } catch (IOException e) {
                e.printStackTrace();
                }
            }
            }
        }
        });
}
}
    4. 使用sqlite数据库
      1. 在内部储存下新建文件夹dataBase,创建数据库,建表
      2. 实例代码 
        package com.jamin.datastorage;

import android.content.ContentValues;
import android.os.Bundle;
import android.view.View;
import android.widget.EditText;
import android.widget.Toast;

import androidx.appcompat.app.AppCompatActivity;

/**
* @author Jamin
* @date 2019/10/12
* @desc 使用sqlite数据库进行添加
*/
public class Main7Activity extends AppCompatActivity {;
private DBOpenHelper dbOpenHelper;

@Override
protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_main7);
    //    初始化对象
    dbOpenHelper = new DBOpenHelper(Main7Activity.this, "db_dict", null, 1);
    final EditText eeditText = findViewById(R.id.eeditText);
    final EditText ceditText = findViewById(R.id.ceditText);
    findViewById(R.id.add)
        .setOnClickListener(
            new View.OnClickListener() {
            @Override
            public void onClick(View v) {
                String en = eeditText.getText().toString();
                String cn = ceditText.getText().toString();
                //                保存数据
                ContentValues contentValues = new ContentValues();
                contentValues.put("word", en);
                contentValues.put("deatil", cn);
                dbOpenHelper.getReadableDatabase().insert("t_dictionary", null, contentValues);
                Toast.makeText(Main7Activity.this, "add success", Toast.LENGTH_SHORT).show();
            }
            });
}

@Override
protected void onDestroy() {
    super.onDestroy();
    if (dbOpenHelper != null) {
    dbOpenHelper.close();
    }
}
}

        package com.jamin.datastorage;

import android.content.Intent;
import android.database.Cursor;
import android.os.Bundle;
import android.util.Log;
import android.view.View;
import android.widget.Button;
import android.widget.EditText;
import android.widget.ListView;
import android.widget.SimpleAdapter;
import android.widget.Toast;

import androidx.appcompat.app.AppCompatActivity;

import java.util.ArrayList;
import java.util.HashMap;
import java.util.List;
import java.util.Map;

/**
* @author Jamin
* @date 2019/10/12
* @desc 使用sqlite数据库进行查询
*/
public class Main6Activity extends AppCompatActivity {
private DBOpenHelper dbOpenHelper;

@Override
protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_main6);
    //    实例化dbOpenHelper对象 上下文对象,数据库名,游标工厂,版本号
    dbOpenHelper = new DBOpenHelper(Main6Activity.this, "db_dict", null, 1);

    final ListView listView = findViewById(R.id.listView);
    final EditText trEditText = findViewById(R.id.treditText);
    Button translationButton = findViewById(R.id.translation);
    Button newWordsButton = findViewById(R.id.newWords);
    //    跳转添加生词
    newWordsButton.setOnClickListener(
        new View.OnClickListener() {
        @Override
        public void onClick(View v) {
            startActivity(new Intent(Main6Activity.this, Main7Activity.class));
        }
        });
    // 查询操作
    translationButton.setOnClickListener(
        new View.OnClickListener() {
        @Override
        public void onClick(View v) {
            Log.d("test", "in");
            String en = trEditText.getText().toString();
            //          查询
            Cursor cursor =
                dbOpenHelper
                    .getReadableDatabase()
                    .query("t_dictionary", null, "word=?", new String[] {en}, null, null, null);
            List<Map<String, String>> maps = new ArrayList<>();
            //            遍历放入集合
            while (cursor.moveToNext()) {
            HashMap<String, String> map = new HashMap<>();
            map.put("word", cursor.getString(1));
            map.put("deatil", cursor.getString(2));
            //              Toast.makeText(Main6Activity.this, map.toString(),
            // Toast.LENGTH_SHORT).show();
            Log.d("test", map.toString());
            maps.add(map);
            }
            if (maps == null || maps.size() == 0) {
            Toast.makeText(Main6Activity.this, "没有查询到数据", Toast.LENGTH_SHORT).show();
            }
            SimpleAdapter simpleAdapter =
                new SimpleAdapter(
                    Main6Activity.this,
                    maps,
                    R.layout.result_main,
                    new String[] {"word", "deatil"},
                    new int[] {R.id.result_en, R.id.result_cn});
            //             适配器输出
            listView.setAdapter(simpleAdapter);
        }
        });
}

@Override
protected void onDestroy() {
    super.onDestroy();
    if (dbOpenHelper != null) {
    dbOpenHelper.close();
    }
}
}
    5. 使用contentProvider 在不同应用程序间实现数据共享
      1. URI与URL
        1. URL: me.csdn.net/weixin_4389… URL协议/网站域名/网站资源
        2. URI: content://com.jamin.test/person/oo1 Android规定/权限(类名)/路径 
          package com.jamin.datastorage;

import android.content.ContentResolver;
import android.database.Cursor;
import android.os.Bundle;
import android.provider.ContactsContract;
import android.widget.TextView;

import androidx.appcompat.app.AppCompatActivity;

/**
* @author Jamin
* @date 2019/10/12
* @desc contentProvider
*/
public class Main8Activity extends AppCompatActivity {

@Override
protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_main8);
    StringBuilder stringBuilder = new StringBuilder();
    ContentResolver contentResolver = getContentResolver();
    //    查询
    Cursor cursor =
        contentResolver.query(ContactsContract.Contacts.CONTENT_URI, null, null, null, null);
    int columnIndex = cursor.getColumnIndex(ContactsContract.Contacts.DISPLAY_NAME);
    //    遍历查询结果
    for (cursor.moveToFirst(); !cursor.isAfterLast(); cursor.moveToNext()) {
    String cursorString = cursor.getString(columnIndex);
    stringBuilder.append(cursorString + "\n");
    }
    TextView textView = findViewById(R.id.textView);
    textView.setText(stringBuilder.toString());
}
}
  2. Handler消息处理
    1. 安卓中的多线程
      1. 进程
        1. 进程: 一个android应用就是一个进程
      2. 线程
        1. 线程: 比进程更小的独立运行的基本单位,一个进程可以包含多个进程
      3. 实例代码
    2. Handler对象 
          package com.jaminhandlermessage;

    import android.os.Bundle;
    import android.os.Handler;
    import android.os.Message;
    import android.view.View;
    import android.widget.Button;
    import android.widget.TextView;

    import androidx.annotation.NonNull;
    import androidx.appcompat.app.AppCompatActivity;

    public class MainActivity extends AppCompatActivity {

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
        final TextView textView = findViewById(R.id.textView);
        final Handler handler =
            new Handler() {
            @Override
            public void handleMessage(@NonNull Message msg) {
                super.handleMessage(msg);
                //            判断消息
                if (msg.what == 0x1234) {
                //                执行操作
                textView.setText("测试2");
                }
            }
            };
        Button button = findViewById(R.id.bt1);
        button.setOnClickListener(
            new View.OnClickListener() {
            @Override
            public void onClick(View v) {
                Thread thread =
                    new Thread(
                        new Runnable() {
                        @Override
                        public void run() {
                            //                          发送消息
                            handler.sendEmptyMessage(0x1234);
                        }
                        });
                thread.start();
            }
            });
    }
    }

          package com.jamin.handlermessage;

    import android.os.Bundle;
    import android.os.Handler;
    import android.os.Message;
    import android.widget.ProgressBar;
    import android.widget.Toast;

    import androidx.appcompat.app.AppCompatActivity;

    import com.jaminhandlermessage.R;

    /**
    * @author Jamin
    * @date 2019/10/13
    * @desc 使用Handler实现进度条
    */
    public class Main2Activity extends AppCompatActivity {
    final int MSG = 0x1234;
    final int MSG2 = 0x1243;
    private int progress = 0;
    private int progress2 = 60;
    private ProgressBar progressBar;
    private ProgressBar progressBar2;

    Handler handler =
        new Handler() {
            @Override
            public void handleMessage(Message msg) {
            super.handleMessage(msg);
            if (msg.what == MSG) {
                if (progress < 100) {
                progressBar.setProgress(++progress);
                handler.sendEmptyMessageDelayed(MSG, 1000);
                } else {
                Toast.makeText(Main2Activity.this, "加载完成", Toast.LENGTH_SHORT).show();
                }
            } else if (msg.what == MSG2) {
                if (progress2 > 0) {
                progressBar2.setProgress(--progress2);
                handler.sendEmptyMessageDelayed(MSG2, 1000);
                } else {
                Toast.makeText(Main2Activity.this, "游戏结束!!", Toast.LENGTH_SHORT).show();
                }
            }
            }
        };

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main2);
        progressBar = findViewById(R.id.progressBar);
        handler.sendEmptyMessage(MSG);
        progressBar2 = findViewById(R.id.progressBar2);
        handler.sendEmptyMessage(MSG2);
    }
    }
    3. Message对象
      1. 属性
        1. arg1 arg2 整形
        2. obj Object类型
        3. replyTo 发送到何处
        4. what 自定义消息代码
      2. 创建
        1. Mesage.obtain()
        2. Handler.obtainMessage()
    4. Looper对象 
      package com.jamin.handlermessage;

import android.os.Handler;
import android.os.Looper;
import android.os.Message;
import android.util.Log;

import androidx.annotation.NonNull;

/**
* @author Jamin <br>
* @date 2019/10/13 18:02 <br>
* @desc Loop <br>
*/
public class LooperThread extends Thread {
private final int MSG = 0x1234;
private Handler handler;

@Override
public void run() {
    super.run();
    Looper.prepare();
    handler =
        new Handler() {
        @Override
        public void handleMessage(@NonNull Message msg) {
            super.handleMessage(msg);

            Log.e("looper", "test" + String.valueOf(MSG));
        }
        };
    Message message = handler.obtainMessage();
    message.what = MSG;
    handler.sendMessage(message);
    Looper.loop();
}
}

      package com.jamin.handlermessage;

import android.os.Bundle;

import androidx.appcompat.app.AppCompatActivity;

import com.jaminhandlermessage.R;

public class Main4Activity extends AppCompatActivity {

@Override
protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_main4);
    LooperThread looperThread = new LooperThread();
    looperThread.start();
}
}
  3. Service
    1. 概述: 能够在后台长时间运行,并且没有用户界面的应用程序组件
    2. 分类
      1. started service:Activity使用startService通知服务启动才启动 生命周期onCreate->onStartCommand()-->Service运行-->stopSelf()/stopService-->service停止-->onDestory()-->service被关闭
      2. boundService: bindService()与Activity同生共死 生命周期 onCrate()--> onBind()-->绑定到Service-->unbindService()-->解绑Service()-->onUnbind()-->onDestory()-->service关闭()
    3. StartedService 
      package com.jamin.service;

import android.app.ActivityManager;
import android.app.Service;
import android.content.Context;
import android.content.Intent;
import android.os.IBinder;
import android.util.Log;

import java.util.ArrayList;

/**
* @author Jamin
* @date 2019/10/13
* @desc 后台打印
*/
public class MyService extends Service {
private int i = 0;

public MyService() {}

@Override
public IBinder onBind(Intent intent) {
    // TODO: Return the communication channel to the service.
    throw new UnsupportedOperationException("Not yet implemented");
}

@Override
public void onCreate() {
    super.onCreate();
}

@Override
public int onStartCommand(Intent intent, int flags, int startId) {

    new Thread(
            new Runnable() {
            @Override
            public void run() {
                while (isRunning()) {
                Log.d("CESHI", String.valueOf(++i));
                try {
                    Thread.sleep(1000);
                } catch (InterruptedException e) {
                    e.printStackTrace();
                }
                }
            }
            })
        .start();
    return super.onStartCommand(intent, flags, startId);
}

@Override
public void onDestroy() {
    super.onDestroy();
}

public boolean isRunning() {
    ActivityManager systemService = (ActivityManager) getSystemService(Context.ACTIVITY_SERVICE);
    //    获取正在运行的服务
    ArrayList<ActivityManager.RunningServiceInfo> runningServiceInfos =
        (ArrayList<ActivityManager.RunningServiceInfo>) systemService.getRunningServices(100);
    for (ActivityManager.RunningServiceInfo runningServiceInfo : runningServiceInfos) {
    //      判断是否是当前服务
    if (runningServiceInfo
        .service
        .getClassName()
        .toString()
        .equals("com.jamin.service.MyService")) {
        return true;
    }
    }
    return false;
}
}

      package com.jamin.service;

import android.content.Intent;
import android.os.Bundle;
import android.view.View;

import androidx.appcompat.app.AppCompatActivity;

public class ServiceActivity extends AppCompatActivity {

@Override
protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_service);
    final Intent intent = new Intent(ServiceActivity.this, MyService.class);
    findViewById(R.id.open)
        .setOnClickListener(
            new View.OnClickListener() {
            @Override
            public void onClick(View v) {
                startService(intent);
            }
            });
    findViewById(R.id.close)
        .setOnClickListener(
            new View.OnClickListener() {
            @Override
            public void onClick(View v) {
                stopService(intent);
            }
            });
}
}

      package com.jamin.service;

import android.app.Service;
import android.content.Intent;
import android.media.MediaPlayer;
import android.os.IBinder;

/**
* @author Jamin
* @date 2019/10/13
* @desc 后台音乐播放
*/
public class MusicService extends Service {
private MediaPlayer mediaPlayer;

public MusicService() {}

@Override
public IBinder onBind(Intent intent) {
    // TODO: Return the communication channel to the service.
    throw new UnsupportedOperationException("Not yet implemented");
}

@Override
public void onCreate() {
    mediaPlayer = MediaPlayer.create(this, R.raw.mp31);
    super.onCreate();
}

@Override
public int onStartCommand(Intent intent, int flags, int startId) {
    if (mediaPlayer.isPlaying()) {

    mediaPlayer.pause();
    } else {

    mediaPlayer.start();
    }

    return super.onStartCommand(intent, flags, startId);
}

@Override
public void onDestroy() {
    //      停止播放
    mediaPlayer.pause();
    mediaPlayer.seekTo(0);
    //     释放资源
    mediaPlayer.release();
    super.onDestroy();
}
}

      package com.jamin.service;

import android.content.Intent;
import android.os.Bundle;
import android.view.View;
import android.widget.Button;

import androidx.appcompat.app.AppCompatActivity;

/**
* @author Jamin 
* @date 2019/10/13
* @desc 后台播放音乐
*/
public class BackgroundSoundActivity extends AppCompatActivity {
private Button button;

@Override
protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_background_sound);
    button = findViewById(R.id.openClose);
    final Intent intent = new Intent(BackgroundSoundActivity.this, MusicService.class);
    button.setOnClickListener(
        new View.OnClickListener() {
        @Override
        public void onClick(View v) {
            /* MediaPlayer mediaPlayer = MediaPlayer.create(BackgroundSoundActivity.this, R.raw.mp31);
            mediaPlayer.start();*/
            startService(intent);
        }
        });
}
}
    4. BoundService 
      package com.jamin.service;

import android.app.Service;
import android.content.Intent;
import android.os.Binder;
import android.os.IBinder;

import java.util.ArrayList;
import java.util.List;
import java.util.Random;

/**
* @author Jamin
* @date 2019/10/14 BinderService
*/
public class BinderService extends Service {
public BinderService() {}

// 销毁
@Override
public void onDestroy() {
    super.onDestroy();
}

@Override
public IBinder onBind(Intent intent) {
    return new MyBinder();
}
/** 产生随机数的方法 */
public List<String> randomNumber() {
    List list = new ArrayList<String>();
    String s = "";
    for (int i = 0; i < 7; i++) {
    int j = new Random().nextInt(33) + 1;
    if (j >= 10) {
        s = String.valueOf(j);
    } else {
        s = "0" + String.valueOf(j);
    }
    list.add(s);
    }
    return list;
}
/** 创建MyBinder内部类 */
public class MyBinder extends Binder {
    // 创建获取Service的方法
    public BinderService getBinderService() {
    return BinderService.this;
    }
}
}

      package com.jamin.service;

import android.content.ComponentName;
import android.content.Intent;
import android.content.ServiceConnection;
import android.os.Bundle;
import android.os.IBinder;
import android.view.View;
import android.widget.Button;
import android.widget.TextView;

import androidx.appcompat.app.AppCompatActivity;

import java.util.List;

/**
* @author Jamin
* @date 2019/10/14
*/
public class Main2Activity extends AppCompatActivity {
private BinderService binderService;
/** textView的id */
private int[] textViewArr =
    new int[] {R.id.t0, R.id.t1, R.id.t2, R.id.t3, R.id.t4, R.id.t5, R.id.t6};

private Button button;
/** service连接对象 */
private ServiceConnection serviceConnection =
    new ServiceConnection() {
        @Override
        public void onServiceConnected(ComponentName name, IBinder service) {
        binderService = ((BinderService.MyBinder) service).getBinderService();
        }

        @Override
        public void onServiceDisconnected(ComponentName name) {}
    };

@Override
protected void onStart() {
    super.onStart();
    Intent intent = new Intent(Main2Activity.this, BinderService.class);
    //    绑定Service
    bindService(intent, serviceConnection, BIND_AUTO_CREATE);
}

@Override
protected void onStop() {
    super.onStop();
    //    解绑service
    unbindService(serviceConnection);
}

@Override
protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_main2);
    button = findViewById(R.id.bt0);
    button.setOnClickListener(
        new View.OnClickListener() {
        @Override
        public void onClick(View v) {
            List<String> list = binderService.randomNumber();
            for (int i = 0; i < list.size(); i++) {
            TextView textView = findViewById(textViewArr[i]);
            textView.setText(list.get(i));
            }
        }
        });
}
}
    5. IntantService 普通service不能自动开启线程,自动销毁,IntentService可以 
      package com.jamin.service;

import android.app.IntentService;
import android.content.Intent;
import android.util.Log;

import androidx.annotation.Nullable;

/**
* @author Jamin <br>
* @date 2019/10/14 16:53 <br>
* @desc IntentService <br>
*/
public class MyIntentService extends IntentService {
/**
* Creates an IntentService. Invoked by your subclass's constructor.
*
* @param name Used to name the worker thread, important only for debugging.
*/
public MyIntentService(String name) {
    super(name);
}

public MyIntentService() {
    super("MyIntentService");
}

@Override
protected void onHandleIntent(@Nullable Intent intent) {
    Log.d("intentService", "开始");
    long endTime = System.currentTimeMillis() + 20 * 1000;
    while (System.currentTimeMillis() < endTime) {
    synchronized (this) {
        try {
        wait(endTime - System.currentTimeMillis());
        } catch (InterruptedException e) {
        e.printStackTrace();
        }
    }
    }
}

@Override
public void onDestroy() {
    super.onDestroy();
    Log.d("service", "jieshu");
}
}

      package com.jamin.service;

import android.app.Service;
import android.content.Intent;
import android.os.IBinder;
import android.util.Log;

/**
* @author Jamin
* @date 2019/10/14
* @desc 普通Service
*/
public class MyService2 extends Service {
public MyService2() {}

@Override
public IBinder onBind(Intent intent) {
    // TODO: Return the communication channel to the service.
    throw new UnsupportedOperationException("Not yet implemented");
}

@Override
public int onStartCommand(Intent intent, int flags, int startId) {
    Log.d("service", "开始");
    long endTime = System.currentTimeMillis() + 20 * 1000;
    while (System.currentTimeMillis() < endTime) {
    synchronized (this) {
        try {
        wait(endTime - System.currentTimeMillis());
        } catch (InterruptedException e) {
        e.printStackTrace();
        }
    }
    }

    return super.onStartCommand(intent, flags, startId);
}

@Override
public void onDestroy() {
    super.onDestroy();
    Log.d("service", "jieshu");
}
}
  4. 传感器
    1. 分类
      1. 光线传感器
      2. 磁场传感器
      3. 加速传感器
      4. 方向传感器
    2. 光线传感器实例代码 
      package com.jamin.sensor;

import android.content.Context;
import android.hardware.Sensor;
import android.hardware.SensorEvent;
import android.hardware.SensorEventListener;
import android.hardware.SensorManager;
import android.os.Bundle;
import android.widget.TextView;

import androidx.appcompat.app.AppCompatActivity;

/**
* @author Jamin
* @date 2019/10/14
* @desc 光线传感器
*/
public class LightActivity extends AppCompatActivity implements SensorEventListener {
private SensorManager sensorManager;
private TextView textView;

@Override
protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_light);
    //    获取传感器管理器
    sensorManager = (SensorManager) getSystemService(Context.SENSOR_SERVICE);
    textView = findViewById(R.id.textView);
}

@Override
protected void onResume() {
    super.onResume();
    //    注册监听器
    sensorManager.registerListener(
        this, sensorManager.getDefaultSensor(Sensor.TYPE_LIGHT), SensorManager.SENSOR_DELAY_GAME);
}

@Override
protected void onPause() {
    super.onPause();
    // 取消注册监听器
    sensorManager.unregisterListener(this);
}

@Override
public void onSensorChanged(SensorEvent event) {
    float[] values = event.values;
    int type = event.sensor.getType();
    if (type == Sensor.TYPE_LIGHT) {
    textView.setText("光线传感器:" + values[0]);
    }
}

@Override
public void onAccuracyChanged(Sensor sensor, int accuracy) {}
}
    3. 磁场传感器实例代码 
      package com.jamin.sensor;

import android.content.Context;
import android.graphics.Bitmap;
import android.graphics.BitmapFactory;
import android.graphics.Canvas;
import android.graphics.Paint;
import android.hardware.Sensor;
import android.hardware.SensorEvent;
import android.hardware.SensorEventListener;
import android.hardware.SensorManager;
import android.util.AttributeSet;
import android.view.View;

import androidx.annotation.Nullable;

/**
* @author Jamin <br>
* @date 2019/10/14 21:28 <br>
* @desc 指针 <br>
*/
public class PointView extends View implements SensorEventListener {
private SensorManager sensorManager;

private Bitmap bitmap;
private float[] value;
private float floatX;
private float floatY;

public PointView(Context context, @Nullable AttributeSet attrs) {
    super(context, attrs);
    sensorManager = (SensorManager) context.getSystemService(Context.SENSOR_SERVICE);
    //    监听器
    sensorManager.registerListener(
        this,
        sensorManager.getDefaultSensor(Sensor.TYPE_MAGNETIC_FIELD),
        SensorManager.SENSOR_DELAY_NORMAL);
    //    加载资源
    bitmap = BitmapFactory.decodeResource(getResources(), R.drawable.compass);
}

@Override
protected void onDraw(Canvas canvas) {
    super.onDraw(canvas);
    if (bitmap != null) {
    //      设置画布选择角度
    canvas.translate(super.getWidth() / 2, super.getWidth() / 2);

    if (floatY == 0 && floatX > 0) {
        canvas.rotate(90);
    } else if (floatY == 0 && floatX < 0) {
        canvas.rotate(-90);
    } else {
        if (floatY > 0) {
        canvas.rotate((float) Math.tanh(floatX / floatY) * 90);
        } else {
        canvas.rotate((float) (180 + Math.tanh(floatX / floatY) * 90));
        }
    }
    }
    canvas.drawBitmap(bitmap, -bitmap.getWidth() / 2, -bitmap.getHeight() / 2, new Paint());
}

@Override
public void onSensorChanged(SensorEvent event) {
    float[] values = event.values;

    int type = event.sensor.getType();
    if (type == Sensor.TYPE_MAGNETIC_FIELD) {
    floatX = values[0];
    floatY = values[1];
    super.postInvalidate();
    }
}

@Override
public void onAccuracyChanged(Sensor sensor, int accuracy) {}
}
    4. 方向传感器
      1. 实例代码 
        package com.jamin.sensor;

import android.content.Context;
import android.graphics.Bitmap;
import android.graphics.Canvas;
import android.graphics.Paint;
import android.hardware.Sensor;
import android.hardware.SensorEvent;
import android.hardware.SensorEventListener;
import android.hardware.SensorManager;
import android.util.AttributeSet;
import android.util.Log;
import android.view.View;

import androidx.annotation.Nullable;

/**
* @author Jamin <br>
* @date 2019/10/15 19:55 <br>
* @desc 水平仪 <br>
*/
public class LevelView extends View implements SensorEventListener {
/** 最大倾斜角度 */
private final int MAX_ANGLE = 30;

private SensorManager sensorManager;
/** 加速度传感器的值 */
private float[] accelerometerValues;
/** 磁场传感器的值 */
private float[] magnticValues;
/** 小球X坐标 */
private float bubbleX;
/** 小球Y坐标 */
private float bubbleY;
/** 小球 */
private Bitmap bubble;
/**
* @param context
* @param attrs
*/
public LevelView(Context context, @Nullable AttributeSet attrs) {
    super(context, attrs);
    sensorManager = (SensorManager) context.getSystemService(Context.SENSOR_SERVICE);
    // 注册磁场监听器
    sensorManager.registerListener(
        this,
        sensorManager.getDefaultSensor(Sensor.TYPE_MAGNETIC_FIELD),
        SensorManager.SENSOR_DELAY_GAME);
    //    注册加速度监听器
    sensorManager.registerListener(
        this,
        sensorManager.getDefaultSensor(Sensor.TYPE_ACCELEROMETER),
        SensorManager.SENSOR_DELAY_GAME);
}

@Override
protected void onDraw(Canvas canvas) {
    super.onDraw(canvas);
    canvas.drawBitmap(bubble, bubble.getWidth() / 2, bubble.getHeight() / 2, new Paint());
}

@Override
public void onSensorChanged(SensorEvent event) {
    // 获取手机触发event的传感器的类型
    int sensorType = event.sensor.getType();
    switch (sensorType) {
    case Sensor.TYPE_ACCELEROMETER:
        accelerometerValues = event.values.clone();
        Log.d("磁场传感器", accelerometerValues.toString());
        break;
    case Sensor.TYPE_MAGNETIC_FIELD:
        magnticValues = event.values.clone();
        Log.d("加速度传感器", magnticValues.toString());
        break;
    default:
        break;
    }
    float[] R = new float[9];
    float[] values = new float[3];
    SensorManager.getRotationMatrix(R, null, accelerometerValues, magnticValues);
    SensorManager.getOrientation(R, values);
    // 手机沿着x轴倾斜 顶部0到-180 底部0-180
    float xAngle = (float) Math.toDegrees(values[1]);
    // 手机沿着y轴倾斜 左侧是0-到-90 右侧是0-90
    float yAngle = (float) Math.toDegrees(values[2]);
    getPostion(xAngle, yAngle);
    super.postInvalidate();
}

private void getPostion(float xAngle, float yAngle) {
    //  获取小球x,y位于中间位置的x,y坐标
    int x = (super.getWidth() - bubble.getWidth()) / 2;
    int y = (super.getHeight() - bubble.getHeight()) / 2;

    if (Math.abs(yAngle) <= MAX_ANGLE) {
    //    y轴倾斜角度越大 小球x坐标越大
    int i = (int) ((super.getWidth() - bubble.getWidth()) / 2 * xAngle / MAX_ANGLE);
    x += i;
    } else if (yAngle > MAX_ANGLE) {
    //      正的倾斜角度超出放在最左边
    x = 0;
    } else {
    //      负的倾斜角度超出放在最右边
    x = super.getWidth() - bubble.getWidth();
    }

    if (Math.abs(xAngle) <= y) {
    //      x轴倾斜角度越大小球x坐标越大
    int i = (int) ((super.getHeight() - bubble.getHeight()) / 2 * yAngle / MAX_ANGLE);
    y -= i;
    } else if (xAngle > MAX_ANGLE) {
    y = 0;
    } else {
    y = super.getHeight() - bubble.getHeight();
    }
    bubbleX = x;
    bubbleY = y;
}

@Override
public void onAccuracyChanged(Sensor sensor, int accuracy) {}
}
  5. 位置服务
    1. LocationProvider 
      package com.jamin.locationprovider;

import android.location.Criteria;
import android.location.LocationManager;
import android.location.LocationProvider;
import android.os.Bundle;
import android.widget.TextView;

import androidx.appcompat.app.AppCompatActivity;

import java.util.Iterator;
import java.util.List;

public class Main2Activity extends AppCompatActivity {

@Override
protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_main2);
    //  获取位置服务
    LocationManager locationManager = (LocationManager) getSystemService(LOCATION_SERVICE);
    //   获取所有位置服务的提供
    List<String> allProviders = locationManager.getAllProviders();
    StringBuilder stringBuilder = new StringBuilder();
    for (Iterator<String> iterator = allProviders.iterator(); iterator.hasNext(); ) {
    stringBuilder.append(iterator.next() + "\n");
    }
    TextView textView = findViewById(R.id.tv0);
    textView.setText(stringBuilder.toString());
    LocationProvider provider = locationManager.getProvider(LocationManager.GPS_PROVIDER);
    TextView textView1 = findViewById(R.id.tv1);
    textView1.setText(provider.getName());
    //    创建过滤条件对象
    Criteria criteria = new Criteria();
    //    不收费
    criteria.setCostAllowed(false);
    // 精度最精确
    criteria.setAccuracy(Criteria.ACCURACY_FINE);
    //    耗电量最低
    criteria.setPowerRequirement(Criteria.POWER_LOW);
    //    获取最佳位置服务
    String bestProvider = locationManager.getBestProvider(criteria, true);
    TextView textView2 = findViewById(R.id.tv2);
    textView2.setText(bestProvider);
}
}
    2. 获取经纬度 
      package com.jamin.locationprovider;

import android.Manifest;
import android.content.pm.PackageManager;
import android.location.Location;
import android.location.LocationListener;
import android.location.LocationManager;
import android.os.Bundle;
import android.widget.TextView;

import androidx.appcompat.app.AppCompatActivity;

public class Main3Activity extends AppCompatActivity {
private TextView textView;

@Override
protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_main3);
    LocationManager locationManager = (LocationManager) getSystemService(LOCATION_SERVICE);
    textView = findViewById(R.id.lcoation);
    //    检查权限
    if (checkSelfPermission(Manifest.permission.ACCESS_FINE_LOCATION)
            != PackageManager.PERMISSION_GRANTED
        && checkSelfPermission(Manifest.permission.ACCESS_COARSE_LOCATION)
            != PackageManager.PERMISSION_GRANTED) {
    // TODO: Consider calling
    //    Activity#requestPermissions
    // here to request the missing permissions, and then overriding
    //   public void onRequestPermissionsResult(int requestCode, String[] permissions,
    //                                          int[] grantResults)
    // to handle the case where the user grants the permission. See the documentation
    // for Activity#requestPermissions for more details.
    return;
    }
    locationManager.requestLocationUpdates(
        //        使用GPS
        LocationManager.GPS_PROVIDER,
        //        间隔时间1s
        1000,
        //  位置间隔1米
        1,
        //        位置更新监听器
        new LocationListener() {
        @Override
        public void onLocationChanged(Location location) {}

        @Override
        public void onStatusChanged(String provider, int status, Bundle extras) {}

        @Override
        public void onProviderEnabled(String provider) {}

        @Override
        public void onProviderDisabled(String provider) {}
        });
    Location lastKnownLocation = locationManager.getLastKnownLocation(LocationManager.GPS_PROVIDER);
    locationUpdate(lastKnownLocation);
}

private void locationUpdate(Location location) {
    StringBuilder stringBuilder = new StringBuilder();
    stringBuilder.append("经度" + location.getLongitude());
    stringBuilder.append("纬度" + location.getLatitude());
    textView.setText(stringBuilder.toString());
}
}
    3. 百度地图的应用 
      package com.jamin.baidumap;

import android.location.Location;
import android.os.Bundle;
import android.util.Log;

import androidx.appcompat.app.AppCompatActivity;

import com.baidu.location.BDLocation;
import com.baidu.location.BDLocationListener;
import com.baidu.location.LocationClient;
import com.baidu.location.LocationClientOption;
import com.baidu.mapapi.CoordType;
import com.baidu.mapapi.SDKInitializer;
import com.baidu.mapapi.map.BaiduMap;
import com.baidu.mapapi.map.BitmapDescriptor;
import com.baidu.mapapi.map.BitmapDescriptorFactory;
import com.baidu.mapapi.map.MapStatus;
import com.baidu.mapapi.map.MapStatusUpdateFactory;
import com.baidu.mapapi.map.MapView;
import com.baidu.mapapi.map.MarkerOptions;
import com.baidu.mapapi.map.MyLocationData;
import com.baidu.mapapi.map.OverlayOptions;
import com.baidu.mapapi.model.LatLng;

/**
* @author Jamin
* @date 2019/10/23
* @desc 初始化地图并配置生命周期
*/
public class MainActivity extends AppCompatActivity implements BDLocationListener {
private MapView mapView;
private BaiduMap baiduMap;
// 防止每次定位都重新设置中心点和marker
private boolean isFirstLocation = true;
// 初始化LocationClient定位类
private LocationClient mLocationClient = null;
// 经纬度
private double lat;
private double lon;

private boolean isFirst = true;

@Override
protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    //    初始化sdk
    SDKInitializer.initialize(getApplicationContext());
    //   设置经纬度类型
    SDKInitializer.setCoordType(CoordType.GCJ02);
    setContentView(R.layout.activity_main);
    mapView = findViewById(R.id.bmapView);
    //    获取百度地图对象
    baiduMap = mapView.getMap();
    // 声明LocationClient类
    mLocationClient = new LocationClient(this);
    // 注册监听函数
    mLocationClient.registerLocationListener(this);
    initLocation();
    // 开始定位
    mLocationClient.start();
}

private void locationUpdate(Location location) {
    if (location != null) {
    LatLng latLng = new LatLng(location.getLatitude(), location.getLongitude());
    Log.d("经纬度", location.getLatitude() + "--------" + location.getLongitude());
    if (isFirst) {
        MapStatus mapStatus = new MapStatus.Builder().target(latLng).zoom(18f).build();

        // 设置地图位置
        baiduMap.animateMapStatus(MapStatusUpdateFactory.newMapStatus(mapStatus));
        isFirst = false;
        //      构造定位数据
        MyLocationData myLocationData =
            new MyLocationData.Builder()
                // 准确性
                .accuracy(location.getAccuracy())
                //                方向
                .direction(100)
                //                纬度
                .latitude(location.getLatitude())
                //                经度
                .longitude(location.getLongitude())
                .build();
        //        设置定位数据
        baiduMap.setMyLocationData(myLocationData);
        //        设置图标
        BitmapDescriptor bitmapDescriptor =
            BitmapDescriptorFactory.fromResource(R.drawable.icon_geo);
        // 构建Marker图标
        BitmapDescriptor bitmap = BitmapDescriptorFactory.fromResource(R.drawable.icon_geo);
        // 构建MarkerOption，用于在地图上添加Marker
        OverlayOptions option = new MarkerOptions().position(latLng).icon(bitmap);
        // 在地图上添加Marker，并显示
        baiduMap.addOverlay(option);
    }
    } else {
    Log.d("经纬度", "无法获取");
    }
}

@Override
protected void onStart() {
    super.onStart();
    baiduMap.setMyLocationEnabled(true);
}

@Override
protected void onStop() {
    super.onStop();
    baiduMap.setMyLocationEnabled(false);
}

@Override
protected void onPause() {
    super.onPause();
    mapView.onPause();
}

@Override
protected void onDestroy() {
    super.onDestroy();
    mapView.onDestroy();
    mapView = null;
}

@Override
protected void onResume() {
    super.onResume();
    mapView.onResume();
}

@Override
public void onReceiveLocation(BDLocation bdLocation) {
    if (isFirst) {
    isFirst = false;
    // 设置并显示中心点
    MyLocationData locData =
        new MyLocationData.Builder()
            .accuracy(bdLocation.getRadius())
            .direction(bdLocation.getRadius())
            .latitude(bdLocation.getLatitude())
            .longitude(bdLocation.getLongitude())
            .build();
    baiduMap.setMyLocationData(locData);

    LatLng ll = new LatLng(bdLocation.getLatitude(), bdLocation.getLongitude());
    MapStatus.Builder builder = new MapStatus.Builder();
    builder.target(ll).zoom(18.0f);
    baiduMap.animateMapStatus(MapStatusUpdateFactory.newMapStatus(builder.build()));
    }
}
/** 配置定位参数 */
private void initLocation() {
    LocationClientOption option = new LocationClientOption();
    // 可选，默认高精度，设置定位模式，高精度，低功耗，仅设备
    option.setLocationMode(LocationClientOption.LocationMode.Hight_Accuracy);
    // 可选，默认gcj02，设置返回的定位结果坐标系
    option.setCoorType("bd09ll");
    // 可选，默认0，即仅定位一次，设置发起定位请求的间隔需要大于等于1000ms才是有效的
    int span = 5000;
    option.setScanSpan(span);
    // 可选，设置是否需要地址信息，默认不需要
    option.setIsNeedAddress(true);
    // 可选，默认false,设置是否使用gps
    option.setOpenGps(true);
    // 可选，默认false，设置是否当GPS有效时按照1S/1次频率输出GPS结果
    option.setLocationNotify(true);
    // 可选，默认false，设置是否需要位置语义化结果，可以在BDLocation.getLocationDescribe里得到，结果类似于“在北京天安门附近”
    option.setIsNeedLocationDescribe(true);
    // 可选，默认false，设置是否需要POI结果，可以在BDLocation.getPoiList里得到
    option.setIsNeedLocationPoiList(true);
    // 可选，默认true，定位SDK内部是一个SERVICE，并放到了独立进程，设置是否在stop的时候杀死这个进程，默认不杀死
    option.setIgnoreKillProcess(false);
    // 可选，默认false，设置是否收集CRASH信息，默认收集
    option.SetIgnoreCacheException(false);
    // 可选，默认false，设置是否需要过滤GPS仿真结果，默认需要
    option.setEnableSimulateGps(false);
    mLocationClient.setLocOption(option);
}
/**
* 设置中心点和添加marker
*
* @param map
* @param bdLocation
* @param isShowLoc
*/
public void setPosition2Center(BaiduMap map, BDLocation bdLocation, Boolean isShowLoc) {
    MyLocationData locData =
        new MyLocationData.Builder()
            .accuracy(bdLocation.getRadius())
            .direction(bdLocation.getRadius())
            .latitude(bdLocation.getLatitude())
            .longitude(bdLocation.getLongitude())
            .build();
    map.setMyLocationData(locData);

    if (isShowLoc) {
    LatLng ll = new LatLng(bdLocation.getLatitude(), bdLocation.getLongitude());
    MapStatus.Builder builder = new MapStatus.Builder();
    builder.target(ll).zoom(18.0f);
    map.animateMapStatus(MapStatusUpdateFactory.newMapStatus(builder.build()));
    }
}
}

      //    将jar和so文件放在libs文件夹下 导入jar包
    sourceSets {
        main {
            jniLibs.srcDirs = ['libs']
        }
    }

      <?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context=".MainActivity">
    <!--百度地图的view-->
    <com.baidu.mapapi.map.MapView
        android:id="@+id/bmapView"
        android:layout_width="match_parent"
        android:layout_height="match_parent"
        android:clickable="true" />
</LinearLayout>
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