五十一、【Bluetooth蓝牙模块】

1.官方网址 https://developer.android.com/guide/topics/connectivity/bluetooth.html

2.步骤

首先，添加蓝牙的权限

<manifest ... >
  <uses-permission android:name="android.permission.BLUETOOTH" />
  <uses-permission android:name="android.permission.BLUETOOTH_ADMIN"/>
  ...
</manifest>

2.1 打开蓝牙 第一种：引导用户收到打开 第二种：BLUETOOTH_ADMIN 可以用的mBluetoothAdapter.enable(); 直接打开

            mBluetoothAdapter = BluetoothAdapter.getDefaultAdapter();

            // 蓝牙是否可用
            if (!mBluetoothAdapter.isEnabled()) {
                // 打开蓝牙
                mBluetoothAdapter.enable();
            }

            // 关闭蓝牙
            if (mBluetoothAdapter.isEnabled()) {
                mBluetoothAdapter.disable();
            }

2.2 扫描附近可用的蓝牙设备 扫描到的结果会通过广播的形式回调，具体可以可以看附录代码：

          // 扫描蓝牙设备
          mBluetoothAdapter.cancelDiscovery();

2.3 连接接 2.4 发送指令 主要是

附录：

import java.io.IOException;
import java.io.OutputStream;
import java.util.ArrayList;
import java.util.UUID;

import android.app.Activity;
import android.bluetooth.BluetoothAdapter;
import android.bluetooth.BluetoothDevice;
import android.bluetooth.BluetoothSocket;
import android.content.BroadcastReceiver;
import android.content.Context;
import android.content.Intent;
import android.content.IntentFilter;
import android.os.Bundle;
import android.view.Menu;
import android.view.MenuItem;
import android.view.View;
import android.widget.AdapterView;
import android.widget.AdapterView.OnItemClickListener;
import android.widget.ListAdapter;
import android.widget.ListView;
import android.widget.Toast;

public class MainActivity extends Activity implements OnItemClickListener {

    private ListView mLv;
    private BluetoothAdapter mBluetoothAdapter;
    private OutputStream mOutputStream;
    private ArrayList<BluetoothDevice> mDevices = new ArrayList<BluetoothDevice>();
    private BroadcastReceiver mBluetoothReceiver = new BroadcastReceiver() {
        @Override
        public void onReceive(Context context, Intent intent) {
            String action = intent.getAction();
            if (BluetoothDevice.ACTION_FOUND.equals(action)) {
                // 扫描到蓝牙设备
                BluetoothDevice device = intent.getParcelableExtra(BluetoothDevice.EXTRA_DEVICE);
                mDevices.add(device);
                mAdapter.notifyDataSetChanged();
                System.out.println("device name" + device.getName());
            } else if (BluetoothAdapter.ACTION_DISCOVERY_STARTED.equals(action)) {
                Toast.makeText(getApplicationContext(), "开始扫描", Toast.LENGTH_SHORT).show();
            } else if (BluetoothAdapter.ACTION_DISCOVERY_FINISHED.equals(action)) {
                Toast.makeText(getApplicationContext(), "扫描结束", Toast.LENGTH_SHORT).show();
            }
        }
    };
    private DeviceAdapter mAdapter;

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
        mLv = (ListView) findViewById(R.id.lv);
        mAdapter = new DeviceAdapter(getApplicationContext(), mDevices);
        mLv.setAdapter(mAdapter);
        mLv.setOnItemClickListener(this);
        mBluetoothAdapter = BluetoothAdapter.getDefaultAdapter();
        // 注册广播接收者, 当扫描到蓝牙设备的时候, 系统会发送广播
        IntentFilter filter = new IntentFilter();
        filter.addAction(BluetoothDevice.ACTION_FOUND);
        filter.addAction(BluetoothAdapter.ACTION_DISCOVERY_STARTED);
        filter.addAction(BluetoothAdapter.ACTION_DISCOVERY_FINISHED);
        registerReceiver(mBluetoothReceiver, filter);
    }

    public void clickBtn(View v) {
        switch (v.getId()) {
        case R.id.button1:
            // 蓝牙是否可用
            if (!mBluetoothAdapter.isEnabled()) {
                // 打开蓝牙
                mBluetoothAdapter.enable();
            }
            break;
        case R.id.button2:
            // 关闭蓝牙
            if (mBluetoothAdapter.isEnabled()) {
                mBluetoothAdapter.disable();
            }
            break;
        case R.id.button3:
            // 开始扫描
            mDevices.clear();
            mAdapter.notifyDataSetChanged();
            mBluetoothAdapter.startDiscovery();
            break;
        case R.id.button4:
            // 停止扫描
            mBluetoothAdapter.cancelDiscovery();
            break;
        case R.id.button5:
            sendCtrl(0);
            break;
        case R.id.button6:
            sendCtrl(1);
            break;
        case R.id.button7:
            sendCtrl(2);
            break;
        default:
            break;
        }
    }

    private void sendCtrl(int i) {
        try {
            byte[] bs = new byte[5];
            bs[0] = (byte)0x01;
            bs[1] = (byte)0x99;
            if(i== 0) {
                bs[2] = (byte)0x10;
                bs[3] = (byte)0x10;
            }else if(i==1) {
                bs[2] = (byte)0x11;
                bs[3] = (byte)0x11;
            }else if(i==2) {
                bs[2] = (byte)0x17;
                bs[3] = (byte)0x17;
            }
            bs[4] = (byte)0x99;
            mOutputStream.write(bs);
        } catch (IOException e) {
            e.printStackTrace();
        }
    }

    @Override
    protected void onDestroy() {
        super.onDestroy();
        unregisterReceiver(mBluetoothReceiver);
    }

    @Override
    public void onItemClick(AdapterView<?> parent, View view, int position, long id) {
        BluetoothDevice device = mDevices.get(position);
        conn(device);
    }

    private void conn(final BluetoothDevice device) {
        // 建立蓝牙连接是耗时操作, 类似TCP Socket, 需要放在子线程里
        new Thread() {
            public void run() {
                try {
                    // 获取 BluetoothSocket, UUID需要和蓝牙服务端保持一致
                    BluetoothSocket bluetoothSocket = device.createRfcommSocketToServiceRecord(UUID
                            .fromString("00001101-0000-1000-8000-00805F9B34FB"));
                    // 和蓝牙服务端建立连接
                    bluetoothSocket.connect();
                    // 获取输出流, 往蓝牙服务端写指令信息
                    mOutputStream = bluetoothSocket.getOutputStream();
                    // 提示用户
                    runOnUiThread(new Runnable() {
                        public void run() {
                            System.out.println("连接成功----");
                            Toast.makeText(getApplicationContext(), "连接成功", Toast.LENGTH_SHORT)
                                    .show();
                        }
                    });
                } catch (IOException e) {
                    e.printStackTrace();
                }
            };
        }.start();
    }
}