Android小程序实现音乐播放列表

package com.example.musiclist;

import android.content.ContentValues;
import android.content.Context;
import android.database.Cursor;
import android.database.sqlite.SQLiteDatabase;
import android.database.sqlite.SQLiteOpenHelper;
import android.os.Bundle;
import android.view.Menu;
import android.view.MenuItem;

public class DBHelper extends SQLiteOpenHelper{
 private static final String DB_NAME = "music.db"; //数据库名称
 private static final String TBL_NAME = "MusicTbl"; //表名
 private SQLiteDatabase db; //声明SQLiteDatabase对象

 //构造函数
 DBHelper(Context c){
  super(c, DB_NAME, null, 2);
 }

 @Override
 public void onCreate(SQLiteDatabase db){
  //获取SQLiteDatabase对象
  this.db = db;
  //创建表
  String CREATE_TBL = "create table MusicTbl(_id integer primary key autoincrement, name text, singer text)";
  db.execSQL(CREATE_TBL);
 }

 //插入
 public void insert(ContentValues values){
  SQLiteDatabase db = getWritableDatabase();
  db.insert(TBL_NAME, null, values);
  db.close();
 }

 //查询
 public Cursor query(){
  SQLiteDatabase db = getWritableDatabase();
  Cursor c = db.query(TBL_NAME, null, null, null, null, null, null);
  return c;
 }

 //删除
 public void del(int id){
  if(db == null){
   db = getWritableDatabase();
  }
  db.delete(TBL_NAME, "_id=?", new String[]{String.valueOf(id)});
 }

 //关闭数据库
 public void close(){
  if(db != null){
   db.close();
  }
 }

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

package com.example.musiclist;

import android.app.Activity;
import android.content.ContentValues;
import android.content.Intent;
import android.os.Bundle;
import android.view.Menu;
import android.view.MenuItem;
import android.view.View;
import android.view.View.OnClickListener;
import android.widget.Button;
import android.widget.EditText;

public class AddActivity extends Activity {
 private EditText et1, et2;
 private Button b1;
 @Override
 public void onCreate(Bundle savedInstanceState) {
  super.onCreate(savedInstanceState);
  setContentView(R.layout.activity_add);
  this.setTitle("添加收藏信息");
  et1 = (EditText)findViewById(R.id.EditTextName);
  et2 = (EditText)findViewById(R.id.EditTextSinger);
  b1 = (Button)findViewById(R.id.ButtonAdd);
  b1.setOnClickListener(new OnClickListener() { 
   public void onClick(View v) {
    // 获取用户输入的文本信息
    String name = et1.getText().toString();
    String singer = et2.getText().toString();

    //创建ContentValues对象。封装记录信息 key 和 values 值成对出现
    ContentValues values = new ContentValues();
    values.put("name", name);
    values.put("singer", singer);

    //创建数据库工具类DBHelper
    DBHelper helper = new DBHelper(getApplicationContext());

    //调用insert()方法插入数据
    helper.insert(values);

    //跳转到QueryActivity，显示音乐列表
    Intent intent = new Intent(AddActivity.this, QueryActivity.class);
    startActivity(intent);
   }
  });
 }
}

<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
 xmlns:tools="http://schemas.android.com/tools"
 android:layout_width="fill_parent"
 android:layout_height="fill_parent"
 android:orientation="vertical"
 android:padding="10dp">

 <TableLayout
  android:id="@ id/TableLayout"
  android:layout_width="wrap_content"
  android:layout_height="wrap_content"
  android:stretchColumns="1">
  "
  <TableRow 
  android:id="@ id/TableRow01"
  android:layout_width="wrap_content"
  android:layout_height="wrap_content">

  <TextView 
   android:id="@ id/TextView01"
   android:layout_width="wrap_content"
   android:layout_height="wrap_content"
   android:text="歌名"/>
  <EditText 
   android:id="@ id/EditTextName"
   android:layout_width="wrap_content"
   android:layout_height="wrap_content"
   android:text=""/> 
  </TableRow>

 <TableRow 
  android:id="@ id/TableRow02"
  android:layout_width="wrap_content"
  android:layout_height="wrap_content">

  <TextView 
   android:id="@ id/TextView02"
   android:layout_width="wrap_content"
   android:layout_height="wrap_content"
   android:text="歌手"/>
  <EditText 
   android:id="@ id/EditTextSinger"
   android:layout_width="wrap_content"
   android:layout_height="wrap_content"
   android:text=""/> 
 </TableRow>

 <Button 
  android:id="@ id/ButtonAdd"
  android:layout_width="wrap_content"
  android:layout_height="wrap_content"
  android:text="添加"/>
 </TableLayout>

</LinearLayout>

package com.example.musiclist;

import android.app.AlertDialog;
import android.app.ListActivity;
import android.content.DialogInterface;
import android.database.Cursor;
import android.os.Bundle;
import android.support.v4.widget.CursorAdapter;
import android.text.AlteredCharSequence;
import android.view.Menu;
import android.view.MenuItem;
import android.view.View;
import android.widget.AdapterView;
import android.widget.AdapterView.OnItemClickListener;
import android.widget.ListView;
import android.widget.SimpleCursorAdapter;

public class QueryActivity extends ListActivity {
 //列表视图
 private ListView listView = null;

 @Override
 public void onCreate(Bundle savedInstanceState) {
  super.onCreate(savedInstanceState);
  this.setTitle("浏览音乐列表信息");
  final DBHelper helpter = new DBHelper(this);

  //获取listview对象，引用变量和实例化对象
  listView = getListView();

  //查询数据，获取游标
  Cursor c = helpter.query();

  //列表项数组
  String[] from = {"_id", "name", "singer"};

  //列表项ID
  int[] to = {R.id.text0, R.id.text1, R.id.text2};

  //适配器
  SimpleCursorAdapter adapter = new SimpleCursorAdapter(this, R.layout.activity_query, c, from, to); //为列表视图添加适配器
  listView.setAdapter(adapter);

  //提示对话框
  final AlertDialog.Builder builder = new AlertDialog.Builder(this);

  //设置ListView单击监听器
  listView.setOnItemClickListener(new OnItemClickListener() {
   @Override
   public void onItemClick(AdapterView<?>arg0, View arg1, int arg2, long arg3){
    final long temp = arg3;
    builder.setMessage("真的要删除该记录吗？").setPositiveButton("是", new DialogInterface.OnClickListener() {
     public void onClick(DialogInterface dialog, int which) {
      //删除数据
      helpter.del((int)temp);
      //重新查询数据
      Cursor c = helpter.query();
      String[] from = {"_id", "name", "singer"};
      int[] to = {R.id.text0, R.id.text1, R.id.text2};
      SimpleCursorAdapter adapter = new SimpleCursorAdapter(getApplicationContext(), R.layout.activity_query, c, from, to); //为列表视图添加适配器
      listView.setAdapter(adapter);
     }
    }).setNegativeButton("否", null);
    AlertDialog ad = builder.create();
    ad.show();
   }
  });
  helpter.close();
 }
}

<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">

 <TextView
  android:id="@ id/text0"
  android:layout_width="wrap_content"
  android:layout_height="wrap_content"
  android:textSize="25px"/>

 <TextView
  android:id="@ id/text1"
  android:layout_width="wrap_content"
  android:layout_height="wrap_content"
  android:textSize="25px"/>

 <TextView
  android:id="@ id/text2"
  android:layout_width="wrap_content"
  android:layout_height="wrap_content"
  android:textSize="25px"/>

</LinearLayout>