安卓大作业，基本的听歌功能，备忘录功能

【实例简介】安卓大作业，基本的听歌功能，备忘录功能
【实例截图】

【核心代码】

package com.example.activity;

import android.content.BroadcastReceiver;
import android.content.Context;
import android.content.Intent;

public class BootReceiver extends BroadcastReceiver {
	@Override
	public void onReceive(Context context, Intent intent) {
		Intent i = new Intent(context, ThirdActivity.class);
		i.setFlags(Intent.FLAG_ACTIVITY_NEW_TASK); // 指定Activity运行在任务栈中
		context.startActivity(i);
	}
}
ackage com.example.activity;

import java.io.File;
import java.util.ArrayList;
import java.util.Random;
import android.app.Activity;
import android.content.ContentResolver;
import android.database.Cursor;
import android.database.sqlite.SQLiteDatabase;
import android.net.Uri;
import android.os.Bundle;
import android.view.View;
import android.widget.Toast;
public class EighthActivity extends Activity {
	private StudentDBOpenHelper helper;
	@Override
	protected void onCreate(Bundle savedInstanceState) {
		super.onCreate(savedInstanceState);
		setContentView(R.layout.activity_eighth);
		helper = new StudentDBOpenHelper(this);
		// readDB();
		readDBFromProvider();
	}
	private void readDBFromProvider() {
		// TODO Auto-generated method stub
		ContentResolver contentResolver = getContentResolver();
		Uri uri = Uri.parse("content://com.example.studentdb/query");
		Cursor cursor = contentResolver.query(uri, null, null, null, null);
		while (cursor.moveToNext()) {
			int id = cursor.getInt(0);
			String name = cursor.getString(1);
			double score = cursor.getDouble(2);

			System.out
					.println("id="   id   ",name="   name   ",score="   score);
		}
		cursor.close();
	}
	private void readDB() {
		// TODO Auto-generated method stub
		File file = new File(
				"/data/data/com.example.activity/databases/info.db");
		System.out.println("文件是否存在："   file.exists());
		SQLiteDatabase db = SQLiteDatabase.openDatabase(
				"/data/data/com.example.activity/databases/info.db", null,
				SQLiteDatabase.OPEN_READWRITE);
		Cursor cursor = db.query("student", null, null, null, null, null, null);
		while (cursor.moveToNext()) {
			int id = cursor.getInt(0);
			String name = cursor.getString(1);
			double score = cursor.getDouble(2);
			System.out
					.println("id="   id   ",name="   name   ",score="   score);
		}
	}
	public void update(View view) {
		SQLiteDatabase db = helper.getWritableDatabase();
		db.execSQL("update student set score=? where name=?", new Object[] {
				"100", "张三54" });
		db.close();
		Toast.makeText(this, "更新成功！", 1).show();
	}
	public void delete(View view) {
		SQLiteDatabase db = helper.getWritableDatabase();
		db.execSQL("delete from student where name=?", new Object[] { "张三16" });
		Toast.makeText(this, "删除成功！", 1).show();
		db.close();
	}
	public void add(View view) {
		SQLiteDatabase db = helper.getWritableDatabase();
		Random random = new Random();
		db.execSQL("insert into student(name,score) values(?,?)", new Object[] {
				"张三"   random.nextInt(100), "98"   random.nextInt(50) });
		Toast.makeText(this, "添加成功！", 1).show();
		db.close();
	}
	public void findAll(View view) {
		SQLiteDatabase db = helper.getReadableDatabase();
		Cursor cursor = db.rawQuery("select *  from student", null);
		ArrayList<Student> list = new ArrayList<Student>();
		while (cursor.moveToNext()) {
			Student student = new Student();
			student.setId(cursor.getInt(0));
			student.setName(cursor.getString(1));
			student.setScore(cursor.getDouble(2));
			list.add(student);
		}
		for (Student student : list) {
			System.out.println(student.toString());
		}
		cursor.close();
		db.close();
		System.out.println("------");
	}
}