Android+Blockly大作业（含登录注册系统、碎片式浏览、Blockly设计）

本文已参与「新人创作礼」活动，一起开启掘金创作之路。

此次大作业实现功能包括： 1.数据库的搭建 2.登录注册界面及主界面界面的设计 3.碎片的应用 4.webBlockly的嵌套 我曾在不同活动调用数据库的bug、数据库的检索和碎片的实现上花了很多时间， 所幸这些问题都解决了，有部分注释标注了曾经的bug所在。 一些调试代码已经删除，使代码看起来简洁一些。 AndroidManifest.xml

<?xml version="1.0" encoding="utf-8"?>
<manifest xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:tools="http://schemas.android.com/tools"
    package="com.example.finaltest">

    <uses-permission android:name="android.permission.INTERNET" />

    <application
        android:allowBackup="true"
        android:icon="@mipmap/ic_launcher"
        android:label="@string/app_name"
        android:roundIcon="@mipmap/ic_launcher_round"
        android:supportsRtl="true"
        android:theme="@style/Theme.FinalTest"
        android:usesCleartextTraffic="true"
        tools:targetApi="m">
        <activity
            android:name=".PoetryActivity"
            android:exported="false" />
        <activity
            android:name=".PoetryContentActivity"
            android:exported="false" />
        <activity
            android:name=".AccessLOLBlocklyActivity"
            android:exported="false" />
        <activity
            android:name=".AccessBilibiliActivity"
            android:exported="false" />
        <activity
            android:name=".RegisterActivity"
            android:exported="false" />
        <activity
            android:name=".LoginActivity"
            android:exported="true">
            <intent-filter>
                <action android:name="android.intent.action.MAIN" />

                <category android:name="android.intent.category.LAUNCHER" />
            </intent-filter>
        </activity>
        <activity
            android:name=".ShowActivity"
            android:exported="false" />
    </application>

</manifest>

AccessBilibiliActivity

package com.example.finaltest;

import androidx.appcompat.app.AppCompatActivity;

import android.os.Bundle;
import android.webkit.WebView;
import android.webkit.WebViewClient;

public class AccessBilibiliActivity extends AppCompatActivity {

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_access_bilibili);
        WebView webView=(WebView) findViewById(R.id.web_view);
        webView.getSettings().setJavaScriptEnabled(true);
        webView.setWebViewClient(new WebViewClient());
        webView.loadUrl("http://www.bilibili.com");
    }
}

AccessLOLBlocklyActivity

package com.example.finaltest;

import androidx.appcompat.app.AppCompatActivity;

import android.os.Bundle;
import android.webkit.WebView;
import android.webkit.WebViewClient;

public class AccessLOLBlocklyActivity extends AppCompatActivity {

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_access_lolblockly);
        WebView webView=(WebView) findViewById(R.id.web_view);
        webView.getSettings().setJavaScriptEnabled(true);
        webView.setWebViewClient(new WebViewClient());
        webView.getSettings().setAllowFileAccess(true);
        webView.loadUrl("file:///android_asset/blockly/code/lolBlockly.html");
    }
}

LoginAcitivity

package com.example.finaltest;

import androidx.appcompat.app.AppCompatActivity;

import android.annotation.SuppressLint;
import android.content.Intent;
import android.database.Cursor;
import android.database.sqlite.SQLiteDatabase;
import android.os.Bundle;
import android.view.View;
import android.widget.Button;
import android.widget.EditText;
import android.widget.Toast;

public class LoginActivity extends AppCompatActivity {

    private EditText accountEdit;
    private EditText passwordEdit;
    private Button login;
    private Button register;
    private MyDatabaseHelper databaseHelper;

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_login);
        databaseHelper=new MyDatabaseHelper(this,"AccountCollector.db",null,1);
        SQLiteDatabase database=databaseHelper.getWritableDatabase();
        accountEdit=(EditText) findViewById(R.id.account);
        passwordEdit=(EditText) findViewById(R.id.password);
        login=(Button) findViewById(R.id.login);
        login.setOnClickListener(new View.OnClickListener() {
            @SuppressLint("Range")
            @Override
            public void onClick(View v) {
                String account=accountEdit.getText().toString();
                String password=passwordEdit.getText().toString();
                Cursor cursor=database.query("Account",null,"account=?",new String[]{account},null,null,null);
                if (cursor.moveToFirst()&&password.equals(cursor.getString(cursor.getColumnIndex("password")))){//曾经的BUG2:需先判断cursor是否找到，否则后者可能非法访问
                    Intent intent=new Intent(LoginActivity.this, ShowActivity.class);
                    startActivity(intent);
                    Toast.makeText(LoginActivity.this,"欢迎，"+account,Toast.LENGTH_LONG).show();
                }else {
                    Toast.makeText(LoginActivity.this,"账号或密码错误",Toast.LENGTH_SHORT).show();
                }
                cursor.close();
            }
        });
        register=(Button) findViewById(R.id.register);
        register.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {
                Intent intent=new Intent(LoginActivity.this,RegisterActivity.class);
                startActivity(intent);
            }
        });
    }
}

MyDatabaseHelper

package com.example.finaltest;

import android.content.Context;
import android.database.sqlite.SQLiteDatabase;
import android.database.sqlite.SQLiteOpenHelper;

public class MyDatabaseHelper extends SQLiteOpenHelper {

    public static final String CREATE_ACCOUNT="create table Account("+"id integer primary key autoincrement,"+"account text,"+"password text)";
    private Context myContext;

    public MyDatabaseHelper(Context context,String name,SQLiteDatabase.CursorFactory factory,int version){
        super(context,name,factory,version);
        myContext=context;
    }

    @Override
    public void onCreate(SQLiteDatabase db) {
        db.execSQL(CREATE_ACCOUNT);
    }

    @Override
    public void onUpgrade(SQLiteDatabase db, int oldVersion, int newVersion) {

    }
}

Poetry

package com.example.finaltest;

import android.content.Context;
import android.database.sqlite.SQLiteDatabase;
import android.database.sqlite.SQLiteOpenHelper;

public class MyDatabaseHelper extends SQLiteOpenHelper {

    public static final String CREATE_ACCOUNT="create table Account("+"id integer primary key autoincrement,"+"account text,"+"password text)";
    private Context myContext;

    public MyDatabaseHelper(Context context,String name,SQLiteDatabase.CursorFactory factory,int version){
        super(context,name,factory,version);
        myContext=context;
    }

    @Override
    public void onCreate(SQLiteDatabase db) {
        db.execSQL(CREATE_ACCOUNT);
    }

    @Override
    public void onUpgrade(SQLiteDatabase db, int oldVersion, int newVersion) {

    }
}

PoetryActivity

package com.example.finaltest;

import androidx.appcompat.app.AppCompatActivity;

import android.os.Bundle;

public class PoetryActivity extends AppCompatActivity {

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_poetry);
    }
}

PoetryContentActivity

package com.example.finaltest;

import androidx.appcompat.app.AppCompatActivity;

import android.content.Context;
import android.content.Intent;
import android.os.Bundle;

public class PoetryContentActivity extends AppCompatActivity {

    public static void actionStart(Context context, String poetryTitle, String poetryContent){
        Intent intent=new Intent(context,PoetryContentActivity.class);
        intent.putExtra("poetry_title",poetryTitle);
        intent.putExtra("poetry_content",poetryContent);
        context.startActivity(intent);
    }
    
    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.poetry_content);
        String poetryTitle=getIntent().getStringExtra("poetry_title");
        String poetryContent=getIntent().getStringExtra("poetry_content");
        PoetryContentFragment poetryContentFragment=(PoetryContentFragment) getSupportFragmentManager().findFragmentById(R.id.poetry_content_fragment);
        poetryContentFragment.refresh(poetryTitle,poetryContent);
    }
}

PoetryContentFragment

package com.example.finaltest;

import android.os.Bundle;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;
import android.widget.TextView;

import androidx.annotation.NonNull;
import androidx.annotation.Nullable;
import androidx.fragment.app.Fragment;

public class PoetryContentFragment extends Fragment {
    private View view;

    @Nullable
    @Override
    public View onCreateView(@NonNull LayoutInflater inflater, @Nullable ViewGroup container, @Nullable Bundle savedInstanceState) {
        view=inflater.inflate(R.layout.poetry_content_fragment,container,false);
        return view;
    }

    public void refresh(String poetryTitle,String poetryContent){
        View visibilityLayout=view.findViewById(R.id.visibility_layout);
        visibilityLayout.setVisibility(view.VISIBLE);
        TextView poetryTitleText=(TextView) view.findViewById(R.id.poetry_title);
        TextView poetryContentText=(TextView) view.findViewById(R.id.poetry_content);
        poetryTitleText.setText(poetryTitle);
        poetryContentText.setText(poetryContent);
    }
}

PoetryTitleFragment

package com.example.finaltest;

import android.os.Bundle;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;
import android.widget.TextView;

import androidx.annotation.NonNull;
import androidx.annotation.Nullable;
import androidx.fragment.app.Fragment;
import androidx.recyclerview.widget.LinearLayoutManager;
import androidx.recyclerview.widget.RecyclerView;

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

public class PoetryTitleFragment extends Fragment {
        private boolean isTwoPane;

    @Override
    public View onCreateView(@NonNull LayoutInflater inflater, @Nullable ViewGroup container, @Nullable Bundle savedInstanceState) {
        View view=inflater.inflate(R.layout.poetry_title_fragment,container,false);
        RecyclerView poetryTitleRecyclerView=(RecyclerView) view.findViewById(R.id.poetry_title_recycler_view);
        LinearLayoutManager layoutManager=new LinearLayoutManager(getActivity());
        poetryTitleRecyclerView.setLayoutManager(layoutManager);
        PoetryAdapter adapter=new PoetryAdapter(getPoetry());
        poetryTitleRecyclerView.setAdapter(adapter);
        return view;
    }

    private List<Poetry>getPoetry(){
        List<Poetry>poetryList=new ArrayList<>();
            Poetry poetry1=new Poetry();
            Poetry poetry2=new Poetry();
            Poetry poetry3=new Poetry();
            Poetry poetry4=new Poetry();
            Poetry poetry5=new Poetry();
            Poetry poetry6=new Poetry();
            Poetry poetry7=new Poetry();
            Poetry poetry8=new Poetry();
            Poetry poetry9=new Poetry();
            Poetry poetry10=new Poetry();
            Poetry poetry11=new Poetry();
            Poetry poetry12=new Poetry();
            Poetry poetry13=new Poetry();
            Poetry poetry14=new Poetry();
            Poetry poetry15=new Poetry();
            Poetry poetry16=new Poetry();
            Poetry poetry17=new Poetry();
            Poetry poetry18=new Poetry();
            Poetry poetry19=new Poetry();
            Poetry poetry20=new Poetry();
            poetry1.setTitle("观沧海");
            poetry1.setContent("                                                                                     东临碣石，以观沧海。\n" +
                    "                                                                                     水何澹澹，山岛竦峙。\n" +
                    "                                                                                     树木丛生，百草丰茂。\n" +
                    "                                                                                     秋风萧瑟，洪波涌起。\n" +
                    "                                                                                     日月之行，若出其中；\n" +
                    "                                                                                     星汉灿烂，若出其里。\n" +
                    "                                                                                     幸甚至哉，歌以咏志。");
            poetryList.add(poetry1);
        poetry2.setTitle("子衿");
        poetry2.setContent("                                                                                     青青子衿，悠悠我心。\n" +
                "                                                                                   纵我不往，子宁不嗣音？\n" +
                "                                                                                     青青子佩，悠悠我思。\n" +
                "                                                                                     纵我不往，子宁不来？\n" +
                "                                                                                     挑兮达兮，在城阙兮。\n" +
                "                                                                                     一日不见，如三月兮。");
        poetryList.add(poetry2);
        poetry3.setTitle("短歌行");
        poetry3.setContent("                                                                                     对酒当歌，人生几何！\n" +
                "                                                                                     譬如朝露，去日苦多。\n" +
                "                                                                                     慨当以慷，忧思难忘。\n" +
                "                                                                                     何以解忧？唯有杜康。\n" +
                "                                                                                     青青子衿，悠悠我心。\n" +
                "                                                                                     但为君故，沉吟至今。\n" +
                "                                                                                     呦呦鹿鸣，食野之苹。\n" +
                "                                                                                     我有嘉宾，鼓瑟吹笙。\n" +
                "                                                                                     明明如月，何时可掇？\n" +
                "                                                                                     忧从中来，不可断绝。\n" +
                "                                                                                     越陌度阡，枉用相存。\n" +
                "                                                                                     契阔谈䜩，心念旧恩。\n" +
                "                                                                                     月明星稀，乌鹊南飞。\n" +
                "                                                                                     绕树三匝，何枝可依？\n" +
                "                                                                                     山不厌高，海不厌深。\n" +
                "                                                                                     周公吐哺，天下归心。");
        poetryList.add(poetry3);
        poetry4.setTitle("龟虽寿");
        poetry4.setContent("                                                                                     神龟虽寿，犹有竟时。\n" +
                "                                                                                     腾蛇乘雾，终为土灰。\n" +
                "                                                                                     老骥伏枥，志在千里。\n" +
                "                                                                                     烈士暮年，壮心不已。\n" +
                "                                                                                     盈缩之期，不但在天；\n" +
                "                                                                                     养怡之福，可得永年。\n" +
                "                                                                                     幸甚至哉，歌以咏志。");
        poetryList.add(poetry4);
        poetry5.setTitle("冬十月");
        poetry5.setContent("                                                                                     孟冬十月，北风徘徊，\n" +
                "                                                                                     天气肃清，繁霜霏霏。\n" +
                "                                                                                     鵾鸡晨鸣，鸿雁南飞，\n" +
                "                                                                                     鸷鸟潜藏，熊罴窟栖。\n" +
                "                                                                                     钱镈停置，农收积场，\n" +
                "                                                                                     逆旅整设，以通贾商。\n" +
                "                                                                                     幸甚至哉！歌以咏志。\n");
        poetryList.add(poetry5);
        poetry6.setTitle("关雎");
        poetry6.setContent("                                                                 关关雎鸠，在河之洲。窈窕淑女，君子好逑。\n" +
                "                                                                 参差荇菜，左右流之。窈窕淑女，寤寐求之。\n" +
                "                                                                 求之不得，寤寐思服。悠哉悠哉，辗转反侧。\n" +
                "                                                                 参差荇菜，左右采之。窈窕淑女，琴瑟友之。\n" +
                "                                                                 参差荇菜，左右芼之。窈窕淑女，钟鼓乐之。");
        poetryList.add(poetry6);
        poetry7.setTitle("樛木");
        poetry7.setContent("                                                                 南有樛木，葛藟累之。乐只君子，福履绥之。\n" +
                "                                                                 南有樛木，葛藟荒之。乐只君子，福履将之。\n" +
                "                                                                 南有樛木，葛藟萦之。乐只君子，福履成之。");
        poetryList.add(poetry7);
        poetry8.setTitle("桃夭");
        poetry8.setContent("                                                                 桃之夭夭，灼灼其华。之子于归，宜其室家。\n" +
                "                                                                 桃之夭夭，有蕡其实。之子于归，宜其家室。\n" +
                "                                                                 桃之夭夭，其叶蓁蓁。之子于归，宜其家人。");
        poetryList.add(poetry8);
        poetry9.setTitle("兔罝");
        poetry9.setContent("                                                                 肃肃兔罝，椓之丁丁。赳赳武夫，公侯干城。\n" +
                "                                                                 肃肃兔罝，施于中逵。赳赳武夫，公侯好仇。\n" +
                "                                                                 肃肃兔罝，施于中林。赳赳武夫，公侯腹心。");
        poetryList.add(poetry9);
        poetry10.setTitle("芣苢");
        poetry10.setContent("                                                                 采采芣苢，薄言采之。采采芣苢，薄言有之。\n" +
                "                                                                 采采芣苢，薄言掇之。采采芣苢，薄言捋之。\n" +
                "                                                                 采采芣苢，薄言袺之。采采芣苢，薄言襭之");
        poetryList.add(poetry10);
        poetry11.setTitle("汉广");
        poetry11.setContent("                                                                 南有乔木，不可休思；汉有游女，不可求思。\n" +
                "                                                                 汉之广矣，不可泳思；江之永矣，不可方思。\n" +
                "                                                                 翘翘错薪，言刈其楚；之子于归，言秣其马。\n" +
                "                                                                 汉之广矣，不可泳思；江之永矣，不可方思。\n" +
                "                                                                 翘翘错薪，言刈其蒌；之子于归，言秣其驹。\n" +
                "                                                                 汉之广矣，不可泳思；江之永矣，不可方思。");
        poetryList.add(poetry11);
        poetry12.setTitle("汝坟");
        poetry12.setContent("                                                                 遵彼汝坟，伐其条枚。未见君子，惄如调饥。\n" +
                "                                                                 遵彼汝坟，伐其条肄。既见君子，不我遐弃。\n" +
                "                                                                 鲂鱼赪尾，王室如毁。虽则如毁，父母孔迩。");
        poetryList.add(poetry12);
        poetry13.setTitle("鹊巢");
        poetry13.setContent("                                                                 维鹊有巢，维鸠居之。之子于归，百两御之。\n" +
                "                                                                 维鹊有巢，维鸠方之。之子于归，百两将之。\n" +
                "                                                                 维鹊有巢，维鸠盈之。之子于归，百两成之。");
        poetryList.add(poetry13);
        poetry14.setTitle("采蘩");
        poetry14.setContent("                                                                 于以采蘩？于沼于沚。于以用之？公侯之事。\n" +
                "                                                                 于以采蘩？于涧之中。于以用之？公侯之宫。\n" +
                "                                                                 被之僮僮，夙夜在公。被之祁祁，薄言还归。");
        poetryList.add(poetry14);
        poetry15.setTitle("采蘋");
        poetry15.setContent("                                                                 于以采蘋？南涧之滨。于以采藻？于彼行潦。\n" +
                "                                                                 于以盛之？维筐及筥。于以湘之？维锜及釜。\n" +
                "                                                                 于以奠之？宗室牖下。谁其尸之？有齐季女。");
        poetryList.add(poetry15);
        poetry16.setTitle("羔羊");
        poetry16.setContent("                                                                 羔羊之皮，素丝五紽。退食自公，委蛇委蛇。\n" +
                "                                                                 羔羊之革，素丝五緎。委蛇委蛇，自公退食。\n" +
                "                                                                 羔羊之缝，素丝五总。委蛇委蛇，退食自公。");
        poetryList.add(poetry16);
        poetry17.setTitle("何彼襛矣");
        poetry17.setContent("                                                                 何彼襛矣，唐棣之华？曷不肃雝？王姬之车。\n" +
                "                                                                 何彼襛矣，华如桃李？平王之孙，齐侯之子。\n" +
                "                                                                 其钓维何？维丝伊缗。齐侯之子，平王之孙。");
        poetryList.add(poetry17);
        poetry18.setTitle("绿衣");
        poetry18.setContent("                                                                 绿兮衣兮，绿衣黄里。心之忧矣，曷维其已？\n" +
                "                                                                 绿兮衣兮，绿衣黄裳。心之忧矣，曷维其亡？\n" +
                "                                                                 绿兮丝兮，女所治兮。我思古人，俾无訧兮。\n" +
                "                                                                 絺兮绤兮，凄其以风。我思古人，实获我心。");
        poetryList.add(poetry18);
        poetry19.setTitle("终风");
        poetry19.setContent("                                                                 终风且暴，顾我则笑。谑浪笑敖，中心是悼。\n" +
                "                                                                 终风且霾，惠然肯来。莫往莫来，悠悠我思。\n" +
                "                                                                 终风且曀，不日有曀。寤言不寐，愿言则嚏。\n" +
                "                                                                 曀曀其阴，虺虺其雷。寤言不寐，愿言则怀。");
        poetryList.add(poetry19);
        poetry20.setTitle("击鼓");
        poetry20.setContent("                                                                 击鼓其镗，踊跃用兵。土国城漕，我独南行。\n" +
                "                                                                 从孙子仲，平陈与宋。不我以归，忧心有忡。\n" +
                "                                                                 爰居爰处？爰丧其马？于以求之？于林之下。\n" +
                "                                                                 死生契阔，与子成说。执子之手，与子偕老。\n" +
                "                                                                 于嗟阔兮，不我活兮。于嗟洵兮，不我信兮。");
        poetryList.add(poetry20);
        return poetryList;
    }

    @Override
    public void onActivityCreated(@Nullable Bundle savedInstanceState) {
        super.onActivityCreated(savedInstanceState);
        isTwoPane= getActivity().findViewById(R.id.poetry_content_layout) != null;
    }

    class PoetryAdapter extends RecyclerView.Adapter<PoetryAdapter.ViewHolder> {
        private List<Poetry> poetryList;

        class ViewHolder extends RecyclerView.ViewHolder {
            TextView poetryTitleText;

            public ViewHolder(View view) {
                super(view);
                poetryTitleText = (TextView) view.findViewById(R.id.poetry_title);
            }
        }

        public PoetryAdapter(List<Poetry> _poetryList) {
            poetryList = _poetryList;
        }

        @NonNull
        @Override
        public ViewHolder onCreateViewHolder(@NonNull ViewGroup parent, int viewType) {
            View view = LayoutInflater.from(parent.getContext()).inflate(R.layout.poetry_item, parent, false);
            final ViewHolder viewHolder = new ViewHolder(view);
            view.setOnClickListener(new View.OnClickListener() {
                @Override
                public void onClick(View v) {
                    Poetry poetry = poetryList.get(viewHolder.getAdapterPosition());
                    if (isTwoPane) {
                        PoetryContentFragment poetryContentFragment = (PoetryContentFragment) getFragmentManager().findFragmentById(R.id.poetry_content_fragment);
                        poetryContentFragment.refresh(poetry.getTitle(), poetry.getContent());
                    } else {
                        PoetryContentActivity.actionStart(getActivity(), poetry.getTitle(), poetry.getContent());
                    }
                }
            });
            return viewHolder;
        }

        @Override
        public void onBindViewHolder(@NonNull ViewHolder holder, int position) {
            Poetry poetry = poetryList.get(position);
            holder.poetryTitleText.setText(poetry.getTitle());
        }

        @Override
        public int getItemCount() {
            return poetryList.size();
        }
    }
}

RegisterActivity

package com.example.finaltest;

import androidx.appcompat.app.AlertDialog;
import androidx.appcompat.app.AppCompatActivity;

import android.content.ContentValues;
import android.content.DialogInterface;
import android.content.Intent;
import android.database.Cursor;
import android.database.sqlite.SQLiteDatabase;
import android.os.Bundle;
import android.view.View;
import android.widget.Button;
import android.widget.EditText;
import android.widget.Toast;

public class RegisterActivity extends AppCompatActivity {

    private MyDatabaseHelper databaseHelper;
    private EditText registerAccountEdit;
    private EditText registerPasswordEdit1;
    private EditText registerPasswordEdit2;
    private Button registerConfirm;

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_register);
        databaseHelper=new MyDatabaseHelper(this,"AccountCollector.db",null,1);//曾经的BUG1:数据库的调用需要在onCreate()中重新new
        SQLiteDatabase database=databaseHelper.getWritableDatabase();
        registerAccountEdit=(EditText)findViewById(R.id.r_account);
        registerPasswordEdit1=(EditText)findViewById(R.id.r_password1);
        registerPasswordEdit2=(EditText)findViewById(R.id.r_password2);
        registerConfirm=(Button)findViewById(R.id.r_confirm);
        registerConfirm.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {
                String registerAccount=registerAccountEdit.getText().toString();
                String registerPassword1=registerPasswordEdit1.getText().toString();
                String registerPassword2=registerPasswordEdit2.getText().toString();
                Cursor cursor=database.query("Account",null,"account=?",new String[]{registerAccount},null,null,null);
                if (!cursor.moveToFirst()&&registerPassword1.equals(registerPassword2)){
                    ContentValues values=new ContentValues();
                    values.put("account",registerAccount);
                    values.put("password",registerPassword1);
                    database.insert("Account",null,values);
                    values.clear();
                    AlertDialog.Builder dialog=new AlertDialog.Builder(RegisterActivity.this);
                    dialog.setTitle("注册成功");
                    dialog.setMessage("请返回登录界面");
                    dialog.setPositiveButton("好", new DialogInterface.OnClickListener() {
                        @Override
                        public void onClick(DialogInterface dialog, int which) {
                            Intent intent=new Intent(RegisterActivity.this,LoginActivity.class);
                            startActivity(intent);
                        }
                    });
                    dialog.show();
                }else if (!cursor.moveToFirst()){
                    AlertDialog.Builder dialog=new AlertDialog.Builder(RegisterActivity.this);
                    dialog.setTitle("注册失败");
                    dialog.setMessage("两次密码输入不一致");
                    dialog.setPositiveButton("好", new DialogInterface.OnClickListener() {
                        @Override
                        public void onClick(DialogInterface dialog, int which) {
                        }
                    });
                    dialog.show();
                }else {
                    AlertDialog.Builder dialog=new AlertDialog.Builder(RegisterActivity.this);
                    dialog.setTitle("注册失败");
                    dialog.setMessage("用户名已存在");
                    dialog.setPositiveButton("好", new DialogInterface.OnClickListener() {
                        @Override
                        public void onClick(DialogInterface dialog, int which) {
                        }
                    });
                    dialog.show();
                }
                cursor.close();
            }
        });
    }
}

ShowActivity

package com.example.finaltest;

import androidx.appcompat.app.AlertDialog;
import androidx.appcompat.app.AppCompatActivity;
import android.content.Intent;
import android.content.DialogInterface;
import android.os.Bundle;
import android.view.View;
import android.widget.ImageView;


public class ShowActivity extends AppCompatActivity {

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_show);
        ImageView imageView1=(ImageView) findViewById(R.id.poetry);
        ImageView imageView2=(ImageView) findViewById(R.id.game);
        ImageView imageView3=(ImageView) findViewById(R.id.bili);
        ImageView imageView4=(ImageView) findViewById(R.id.logout);
        imageView1.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {
                Intent intent=new Intent(ShowActivity.this,PoetryActivity.class);
                startActivity(intent);
            }
        });
        imageView2.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {
                Intent intent=new Intent(ShowActivity.this,AccessLOLBlocklyActivity.class);
                startActivity(intent);
            }
        });imageView3.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {
                Intent intent=new Intent(ShowActivity.this,AccessBilibiliActivity.class);
                startActivity(intent);
            }
        });imageView4.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {
                AlertDialog.Builder dialog=new AlertDialog.Builder(ShowActivity.this);
                dialog.setTitle("退出登录");
                dialog.setMessage("你确定吗？");
                dialog.setPositiveButton("确定", new DialogInterface.OnClickListener() {
                    @Override
                    public void onClick(DialogInterface dialog, int which) {
                        finish();
                    }
                });
                dialog.setNegativeButton("取消", new DialogInterface.OnClickListener() {
                    @Override
                    public void onClick(DialogInterface dialog, int which) {
                    }
                });
                dialog.show();
            }
        });
    }
}

activity_access_bilibili.xml

<?xml version="1.0" encoding="utf-8"?>
<androidx.constraintlayout.widget.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context=".AccessBilibiliActivity">

    <WebView
        android:layout_width="match_parent"
        android:layout_height="match_parent"
        android:id="@+id/web_view"/>

</androidx.constraintlayout.widget.ConstraintLayout>

activity_access_lolblockly.xml

<?xml version="1.0" encoding="utf-8"?>
<androidx.constraintlayout.widget.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context=".AccessLOLBlocklyActivity">

    <WebView
        android:layout_width="match_parent"
        android:layout_height="match_parent"
        android:id="@+id/web_view"/>

</androidx.constraintlayout.widget.ConstraintLayout>

activity_login.xml

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:orientation="vertical"
    android:background="@drawable/bg1"
    tools:context=".LoginActivity">

    <TextView
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:layout_gravity="center_vertical"
        android:gravity="center"
        android:text="请登录"
        android:textSize="36sp" />

    <LinearLayout
        android:layout_width="500dp"
        android:layout_height="60dp"
        android:layout_gravity="center"
        android:orientation="horizontal">

        <TextView
            android:layout_width="90dp"
            android:layout_height="wrap_content"
            android:layout_gravity="center_vertical"
            android:text="用户名:"
            android:textSize="18sp" />

        <EditText
            android:id="@+id/account"
            android:layout_width="0dp"
            android:layout_height="wrap_content"
            android:layout_gravity="center_vertical"
            android:layout_weight="1"
            android:hint="请输入用户名"/>
    </LinearLayout>

    <LinearLayout
        android:layout_width="500dp"
        android:layout_height="60dp"
        android:layout_gravity="center"
        android:orientation="horizontal">

        <TextView
            android:layout_width="90dp"
            android:layout_height="wrap_content"
            android:layout_gravity="center_vertical"
            android:text="密码:"
            android:textSize="18sp" />

        <EditText
            android:id="@+id/password"
            android:layout_width="0dp"
            android:layout_height="wrap_content"
            android:layout_gravity="center_vertical"
            android:layout_weight="1"
            android:inputType="textPassword"
            android:hint="请输入密码"/>
    </LinearLayout>

    <LinearLayout
        android:layout_width="600dp"
        android:layout_height="60dp"
        android:layout_gravity="center"
        android:orientation="horizontal">

        <Button
            android:id="@+id/login"
            android:layout_width="0dp"
            android:layout_height="60dp"
            android:layout_weight="1"
            android:text="登录"
            android:textSize="18sp" />

        <TextView
            android:layout_width="0dp"
            android:layout_height="60dp"
            android:layout_weight="1" />

        <Button
            android:id="@+id/register"
            android:layout_width="0dp"
            android:layout_height="60dp"
            android:layout_weight="1"
            android:text="注册"
            android:textSize="18sp" />
    </LinearLayout>

</LinearLayout>

activity_poetry.xml

<?xml version="1.0" encoding="utf-8"?>
<androidx.constraintlayout.widget.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:id="@+id/poetry_title_layout"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context=".PoetryActivity">

    <fragment
        android:layout_width="match_parent"
        android:layout_height="match_parent"
        android:id="@+id/poetry_title_fragment"
        android:name="com.example.finaltest.PoetryTitleFragment"/>

</androidx.constraintlayout.widget.ConstraintLayout>

activity_poetry.xml(sw600dp)

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:orientation="horizontal"
    android:layout_width="match_parent"
    android:layout_height="match_parent">

    <fragment
        android:layout_width="0dp"
        android:layout_height="match_parent"
        android:layout_weight="1"
        android:id="@+id/nws_title_fragment"
        android:name="com.example.finaltest.PoetryTitleFragment"/>

    <FrameLayout
        android:layout_width="0dp"
        android:layout_height="match_parent"
        android:layout_weight="3"
        android:id="@+id/poetry_content_layout">
        <fragment
            android:layout_width="match_parent"
            android:layout_height="match_parent"
            android:id="@+id/poetry_content_fragment"
            android:name="com.example.finaltest.PoetryContentFragment"/>
    </FrameLayout>

</LinearLayout>

activity_register.xml

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:orientation="vertical"
    android:background="@drawable/bg1"
    tools:context=".RegisterActivity">

    <TextView
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:layout_gravity="center_vertical"
        android:gravity="center"
        android:text="请注册"
        android:textSize="36sp" />

    <LinearLayout
        android:layout_width="500dp"
        android:layout_height="60dp"
        android:layout_gravity="center"
        android:orientation="horizontal">

        <TextView
            android:layout_width="90dp"
            android:layout_height="wrap_content"
            android:layout_gravity="center_vertical"
            android:text="用户名:"
            android:textSize="18sp" />

        <EditText
            android:id="@+id/r_account"
            android:layout_width="0dp"
            android:layout_height="wrap_content"
            android:layout_gravity="center_vertical"
            android:layout_weight="1"
            android:hint="请输入用户名"/>
    </LinearLayout>

    <LinearLayout
        android:layout_width="500dp"
        android:layout_height="60dp"
        android:layout_gravity="center"
        android:orientation="horizontal">

        <TextView
            android:layout_width="90dp"
            android:layout_height="wrap_content"
            android:layout_gravity="center_vertical"
            android:text="密码:"
            android:textSize="18sp" />

        <EditText
            android:id="@+id/r_password1"
            android:layout_width="0dp"
            android:layout_height="wrap_content"
            android:layout_gravity="center_vertical"
            android:layout_weight="1"
            android:inputType="textPassword"
            android:hint="请输入密码"/>
    </LinearLayout>

    <LinearLayout
        android:layout_width="500dp"
        android:layout_height="60dp"
        android:layout_gravity="center"
        android:orientation="horizontal">

        <TextView
            android:layout_width="90dp"
            android:layout_height="wrap_content"
            android:layout_gravity="center_vertical"
            android:text="确认密码:"
            android:textSize="18sp" />

        <EditText
            android:id="@+id/r_password2"
            android:layout_width="0dp"
            android:layout_height="wrap_content"
            android:layout_gravity="center_vertical"
            android:layout_weight="1"
            android:inputType="textPassword"
            android:hint="请再次输入密码"/>
    </LinearLayout>

    <Button
        android:layout_width="400dp"
        android:layout_height="wrap_content"
        android:id="@+id/r_confirm"
        android:text="确定"
        android:layout_gravity="center"/>

</LinearLayout>

activity_show.xml

<?xml version="1.0" encoding="utf-8"?>
<androidx.constraintlayout.widget.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:background="@drawable/bg2"
    tools:context=".ShowActivity">


    <ImageView
        android:id="@+id/poetry"
        android:layout_width="200dp"
        android:layout_height="200dp"
        android:layout_marginBottom="10dp"
        android:visibility="visible"
        android:background="@drawable/img1"
        app:layout_constraintBottom_toTopOf="@+id/bili"
        app:layout_constraintEnd_toEndOf="@+id/bili"
        app:layout_constraintHorizontal_bias="1.0"
        app:layout_constraintStart_toStartOf="@+id/bili" />
    
    <ImageView
        android:id="@+id/game"
        android:layout_width="200dp"
        android:layout_height="200dp"
        android:visibility="visible"
        android:background="@drawable/img2"
        app:layout_constraintBottom_toBottomOf="parent"
        app:layout_constraintEnd_toEndOf="parent"
        app:layout_constraintHorizontal_bias="0.385"
        app:layout_constraintStart_toStartOf="parent"
        app:layout_constraintTop_toTopOf="parent"
        app:layout_constraintVertical_bias="0.407" />

    <ImageView
        android:id="@+id/bili"
        android:layout_width="200dp"
        android:layout_height="200dp"
        android:layout_marginEnd="20dp"
        android:visibility="visible"
        android:background="@drawable/img3"
        app:layout_constraintBottom_toBottomOf="@+id/logout"
        app:layout_constraintEnd_toStartOf="@+id/logout"
        app:layout_constraintTop_toTopOf="@+id/logout"
        app:layout_constraintVertical_bias="0.0" />

    

    <ImageView
        android:id="@+id/logout"
        android:layout_width="200dp"
        android:layout_height="200dp"
        android:layout_marginTop="10dp"
        android:visibility="visible"
        android:background="@drawable/img4"
        app:layout_constraintEnd_toEndOf="@+id/game"
        app:layout_constraintHorizontal_bias="0.0"
        app:layout_constraintStart_toStartOf="@+id/game"
        app:layout_constraintTop_toBottomOf="@+id/game" />

</androidx.constraintlayout.widget.ConstraintLayout>

poetry_content.xml

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:orientation="vertical"
    tools:context=".PoetryContentActivity">

    <fragment
        android:layout_width="match_parent"
        android:layout_height="match_parent"
        android:id="@+id/poetry_content_fragment"
        android:name="com.example.finaltest.PoetryContentFragment"/>
</LinearLayout>

poetry_content_fragment.xml

<?xml version="1.0" encoding="utf-8"?>
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:layout_width="match_parent"
    android:layout_height="match_parent">

    <LinearLayout
        android:layout_width="match_parent"
        android:layout_height="match_parent"
        android:id="@+id/visibility_layout"
        android:orientation="vertical"
        android:visibility="invisible">

        <TextView
            android:layout_width="match_parent"
            android:layout_height="wrap_content"
            android:id="@+id/poetry_title"
            android:gravity="center"
            android:padding="10dp"
            android:textSize="20sp"/>

        <View
            android:layout_width="match_parent"
            android:layout_height="1dp"
            android:background="#000000"/>

        <TextView
            android:layout_width="match_parent"
            android:layout_height="0dp"
            android:layout_weight="1"
            android:id="@+id/poetry_content"
            android:padding="15dp"
            android:textSize="18sp"/>

    </LinearLayout>

    <View
        android:layout_width="1dp"
        android:layout_height="match_parent"
        android:layout_alignParentLeft="true"
        android:background="#000000"/>

</RelativeLayout>

poetry_item.xml

<?xml version="1.0" encoding="utf-8"?>
<TextView xmlns:android="http://schemas.android.com/apk/res/android"
    android:layout_width="match_parent"
    android:layout_height="wrap_content"
    android:id="@+id/poetry_title"
    android:maxLines="1"
    android:ellipsize="end"
    android:textSize="18sp"
    android:paddingLeft="10dp"
    android:paddingRight="10dp"
    android:paddingTop="15dp"
    android:paddingBottom="15dp"/>

poetry_title_fragment.xml

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:orientation="vertical"
    android:layout_width="match_parent"
    android:layout_height="match_parent">

    <androidx.recyclerview.widget.RecyclerView
        android:layout_width="match_parent"
        android:layout_height="match_parent"
        android:id="@+id/poetry_title_recycler_view"/>

</LinearLayout>

另外： 1.blockly放在assets中，自动生成的代码过长，建议自己去develop 2.登录注册系统需自己搭建SQLite数据库（安卓自带），详情参考《Android第一行代码》By 郭霖