Android小程序-乐学成语收藏（三）

目标效果：

在学习时收藏成语，切换到收藏页面可以显示收藏过的成语，点击右边的红色五角星可以删除该成语。

1.新建CollectActivity.java页面和activity_collect.xml页面作为收藏页面。

activity_collect.xml页面：

<RelativeLayout 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"    android:background="@drawable/bg_ling"    tools:context=".GameActivity" >    <ListView        android:id="@+id/lvCollect"        android:layout_width="match_parent"        android:layout_height="match_parent">    </ListView></RelativeLayout>

2.新建MyDatabaseHelper.java页面创建收藏表存储收藏信息。

MyDatabaseHelper.java页面：

package cn.edu.bztc.happyidiom.db;import android.content.Context;import android.database.sqlite.SQLiteDatabase;import android.database.sqlite.SQLiteOpenHelper;public class MyDatabaseHelper extends SQLiteOpenHelper {public static final String DB_COLLECT_NAME = "collect.db";// 数据库名public static final int COLLECT_VERSION = 1;// 数据库版本号public static final String TABLE_COLLECT = "collect";// 表名public static final String COLLECT_ID = "id";// id字段public static final String COLLECT_NAME = "name";// 成语名称public static final String COLLECT_PRO = "pronounce";// 成语发音public static final String COLLECT_EXP = "explain";// 成语解释public static final String COLLECT_ANT = "antonym";// 反义词public static final String COLLECT_HOM = "homoionym";// 同义词public static final String COLLECT_DER = "derivation";// 源自public static final String COLLECT_EXA = "examples";// 例子public static final String CREATE_COLLECT = "create table collect (id integer primary key autoincrement,name text,pronounce text,explain text,antonym text,homoionym text,derivation text,examples text)";public MyDatabaseHelper(Context context) {super(context, DB_COLLECT_NAME, null, COLLECT_VERSION);}@Overridepublic void onCreate(SQLiteDatabase db) {db.execSQL(CREATE_COLLECT);// 执行创建数据库的SQL语句}@Overridepublic void onUpgrade(SQLiteDatabase arg0, int arg1, int arg2) {}}

3.新建CollectDao.java页面作为收藏表的操作页面。

CollectDao.java页面：

package cn.edu.bztc.happyidiom.dao;import java.util.ArrayList;import java.util.List;import android.content.ContentValues;import android.content.Context;import android.database.Cursor;import android.database.sqlite.SQLiteDatabase;import android.util.Log;import cn.edu.bztc.happyidiom.db.MyDatabaseHelper;import cn.edu.bztc.happyidiom.entity.Animal;public class CollectDao {private static CollectDao collectDao;SQLiteDatabase db;MyDatabaseHelper mydatabaseHelper;public CollectDao(Context context){mydatabaseHelper=new MyDatabaseHelper(context);}public synchronized static CollectDao getInstance(Context context){if(collectDao==null){collectDao=new CollectDao(context);}return collectDao;}/*添加收藏*/public void add(Animal animal) {db=mydatabaseHelper.getWritableDatabase();ContentValues value=new ContentValues();value.put(MyDatabaseHelper.COLLECT_NAME,animal.getName());value.put(MyDatabaseHelper.COLLECT_PRO,animal.getPronounce());value.put(MyDatabaseHelper.COLLECT_EXP,animal.getExplain());value.put(MyDatabaseHelper.COLLECT_ANT,animal.getAntonym());value.put(MyDatabaseHelper.COLLECT_HOM,animal.getHomoionym());value.put(MyDatabaseHelper.COLLECT_DER,animal.getDerivation());value.put(MyDatabaseHelper.COLLECT_EXA,animal.getExamples());db.insert(MyDatabaseHelper.TABLE_COLLECT,null,value);value.clear();}/*从数据库读取所有的动物类成语*/public List<Animal> getAllAnimals(List<Animal> list){db=mydatabaseHelper.getReadableDatabase();Cursor cursor=db.query("collect",null,null,null,null,null,null);if(cursor.moveToNext()){do{Animal animal=new Animal();animal.setId(cursor.getInt(cursor.getColumnIndex("id")));animal.setName(cursor.getString(cursor.getColumnIndex("name")));animal.setPronounce(cursor.getString(cursor.getColumnIndex("pronounce")));animal.setAntonym(cursor.getString(cursor.getColumnIndex("antonym")));animal.setHomoionym(cursor.getString(cursor.getColumnIndex("homoionym")));animal.setDerivation(cursor.getString(cursor.getColumnIndex("derivation")));animal.setExamples(cursor.getString(cursor.getColumnIndex("examples")));animal.setExplain(cursor.getString(cursor.getColumnIndex("explain")));list.add(animal);}while(cursor.moveToNext());}cursor.close();return list;}/*根据id删除收藏信息*/public void del(int id){db=mydatabaseHelper.getWritableDatabase();db.delete(mydatabaseHelper.TABLE_COLLECT,mydatabaseHelper.COLLECT_ID+"=?",new String[]{String.valueOf(id)});}}

4.创建CollectAdapter.java页面为适配器，配置数据源和ListView。

CollectAdapter.java页面：

package cn.edu.bztc.happyidiom.adapter;import java.util.List;import android.app.AlertDialog;import android.content.Context;import android.content.DialogInterface;import android.util.Log;import android.view.LayoutInflater;import android.view.View;import android.view.View.OnClickListener;import android.view.ViewGroup;import android.widget.ArrayAdapter;import android.widget.ImageButton;import android.widget.TextView;import android.widget.Toast;import cn.edu.bztc.happyidiom.dao.CollectDao;import cn.edu.bztc.happyidiom.entity.Animal;import cn.edu.bztc.happyidiom.minterface.ChangeListData;import cn.edu.bztc.happyidion.activity.CollectActivity;import cn.edu.bztc.happyidion.activity.MainActivity;import cn.edu.bztc.happyidion.activity.R;public class CollectAdapter extends ArrayAdapter<Animal> {private int resourceId;private Context context;private ChangeListData mChangeListData;public CollectAdapter(Context context, int resource, List<Animal> objects) {super(context, resource, objects);this.context = context;resourceId = resource;}public ChangeListData getChangeListData() {return mChangeListData;}public void setChangeListData(ChangeListData mChangeListData) {this.mChangeListData = mChangeListData;}@Overridepublic View getView(int position, View convertView, ViewGroup parent) {final Animal animal = getItem(position);// 获取当前项的Animal实例View view;ViewHolder viewHolder;if (convertView == null) {// 判断是否第一次运行，如果是则进入，并将上下文环境保存进convertViewview = LayoutInflater.from(getContext()).inflate(resourceId, null);viewHolder = new ViewHolder();viewHolder.tvName = (TextView) view.findViewById(R.id.tvName);viewHolder.btnDel = (ImageButton) view.findViewById(R.id.btnDel);viewHolder.btnDel.setOnClickListener(new OnClickListener() {@Overridepublic void onClick(View arg0) {/* 弹出提示框 */showDialog();}/* 弹出提示框 */private void showDialog() {AlertDialog.Builder builder = new AlertDialog.Builder(context);builder.setMessage("确定删除？");// 设置内容/* 添加对话框中确定按钮和点击事件 */builder.setPositiveButton("确定", new DialogInterface.OnClickListener() {@Overridepublic void onClick(DialogInterface arg0, int arg1) {CollectDao collectDao = new CollectDao(context);collectDao.del(animal.getId());Toast.makeText(context, "删除成功", Toast.LENGTH_SHORT).show();if (mChangeListData != null)mChangeListData.changedata();}});/* 添加对话框中取消按钮和点击事件 */builder.setNegativeButton("取消", new DialogInterface.OnClickListener() {@Overridepublic void onClick(DialogInterface arg0, int arg1) {}});AlertDialog dialog = builder.create();// 获取dialogdialog.show();// 显示对话框}});view.setTag(viewHolder);} else {// 如果不是第一次运行，convertView不为空，直接取出赋值给viewview = convertView;viewHolder = (ViewHolder) view.getTag();}viewHolder.tvName.setText(animal.getName());// 显示成语return view;}class ViewHolder {TextView tvName;ImageButton btnDel;}}

5.新建ChangeListData.java接口，用于删除时调用。

ChangeListData.java页面：

package cn.edu.bztc.happyidiom.minterface;public interface ChangeListData {public void changedata();}

6.CollectActivity.java页面设置ListView的点击事件。

CollectActivity.java页面：

package cn.edu.bztc.happyidion.activity;import java.util.ArrayList;import java.util.List;import cn.edu.bztc.happyidiom.adapter.CollectAdapter;import cn.edu.bztc.happyidiom.dao.CollectDao;import cn.edu.bztc.happyidiom.entity.Animal;import cn.edu.bztc.happyidiom.minterface.ChangeListData;import cn.edu.bztc.happyidiom.util.DialogUtil;import android.os.Bundle;import android.app.Activity;import android.util.Log;import android.view.Menu;import android.view.View;import android.widget.AdapterView;import android.widget.AdapterView.OnItemClickListener;import android.widget.ListView;public class CollectActivity extends Activity {private List<Animal> collectList = new ArrayList<Animal>();private CollectDao collectDao;private ListView lvCollect;@Overrideprotected void onCreate(Bundle savedInstanceState) {super.onCreate(savedInstanceState);setContentView(R.layout.activity_collect);initAnimals();lvCollect = (ListView) findViewById(R.id.lvCollect);final CollectAdapter collectAdapter = new CollectAdapter(this,R.layout.collect_item, collectList);lvCollect.setAdapter(collectAdapter);lvCollect.setOnItemClickListener(new OnItemClickListener() {@Overridepublic void onItemClick(AdapterView<?> adapterView, View view,int position, long id) {Animal animal = collectList.get(position);/* 定义对话框中提示语句 */String result = animal.getName() + "\n" + animal.getPronounce()+ "\n【解释】：" + animal.getExplain() + "\n【近义词】："+ animal.getHomoionym() + "\n【反义词】："+ animal.getAntonym()+ "\n【来源】："+ animal.getDerivation() + "\n【示例】："+ animal.getExamples();DialogUtil.showDialog(result, CollectActivity.this);}});collectAdapter.setChangeListData(new ChangeListData() {/*刷新ListView*/@Overridepublic void changedata() {collectList.clear();collectDao.getAllAnimals(collectList);collectAdapter.notifyDataSetChanged();}});}/* 获取数据库中的收藏集合 */private void initAnimals() {collectDao = CollectDao.getInstance(this);collectDao.getAllAnimals(collectList);}}

7.修改MainActivity.java页面，一是创建了一个数据库存储收藏表，二是更改了TabHost子页面的绑定方式，原先那种运行程序只会在一开始创建页面，之后更改页面信息都不会再动态刷新，更改后收藏列表可以显示出来。

MainActivity.java页面：

package cn.edu.bztc.happyidion.activity;import cn.edu.bztc.happyidiom.db.MyDatabaseHelper;import android.app.TabActivity;import android.content.Intent;import android.os.Bundle;import android.view.Menu;import android.view.Window;import android.widget.TabHost;public class MainActivity extends TabActivity {private TabHost tabHost;// 导航栏控件@Overrideprotected void onCreate(Bundle savedInstanceState) {super.onCreate(savedInstanceState);requestWindowFeature(Window.FEATURE_NO_TITLE);// 取消标题栏setContentView(R.layout.activity_main);createCollectDatabase();tabHost = getTabHost(); // 获取TabHost实例/* 一个Tab对应一个name名称，一个标题，一个图标，yigeActivity页面 */// addTab("study",R.string.title_study,R.drawable.study,StudyActivity.class);// addTab("search",R.string.title_search,R.drawable.search,SearchActivity.class);// addTab("game",R.string.title_game,R.drawable.game,GameActivity.class);// addTab("save",R.string.title_save,R.drawable.save,CollectActivity.class);// addTab("help",R.string.title_help,R.drawable.help,StudyActivity.class);tabHost.addTab(tabHost.newTabSpec("study").setIndicator("学习",getResources().getDrawable(R.drawable.study)).setContent(new Intent(this, StudyActivity.class).addFlags(Intent.FLAG_ACTIVITY_CLEAR_TOP)));tabHost.addTab(tabHost.newTabSpec("search").setIndicator("搜索",getResources().getDrawable(R.drawable.search)).setContent(new Intent(this, SearchActivity.class).addFlags(Intent.FLAG_ACTIVITY_CLEAR_TOP)));tabHost.addTab(tabHost.newTabSpec("game").setIndicator("游戏",getResources().getDrawable(R.drawable.game)).setContent(new Intent(this, GameActivity.class).addFlags(Intent.FLAG_ACTIVITY_CLEAR_TOP)));tabHost.addTab(tabHost.newTabSpec("save").setIndicator("收藏",getResources().getDrawable(R.drawable.save)).setContent(new Intent(this, CollectActivity.class).addFlags(Intent.FLAG_ACTIVITY_CLEAR_TOP)));tabHost.addTab(tabHost.newTabSpec("help").setIndicator("帮助",getResources().getDrawable(R.drawable.help)).setContent(new Intent(this, StudyActivity.class).addFlags(Intent.FLAG_ACTIVITY_CLEAR_TOP)));}/* 创建收藏数据库 */private void createCollectDatabase() {MyDatabaseHelper mydatabaseHelper = new MyDatabaseHelper(MainActivity.this);mydatabaseHelper.getWritableDatabase();}/* 定义每个Tab的显示内容 */private void addTab(String tag, int title_introduction, int title_icon,Class ActivityClass) {tabHost.addTab(tabHost.newTabSpec(tag).setIndicator(getString(title_introduction),getResources().getDrawable(title_icon)).setContent(new Intent(this, ActivityClass)));}@Overridepublic boolean onCreateOptionsMenu(Menu menu) {getMenuInflater().inflate(R.menu.main, menu);return true;}}

8.程序源码：点击打开链接

9.运行就可以显示目标效果了。