Android开发中对SharedPreferences的操作

package com.preferences;

import android.app.Activity;
import android.content.SharedPreferences;
import android.os.Bundle;
import android.view.KeyEvent;
import android.widget.TextView;

public class Activity01 extends Activity {
private boolean mbMusic = false;
private TextView mTextView = null;
private TextView mTextView1 = null;
private String text = "ni shishui";
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.main);
mTextView = (TextView) this.findViewById(R.id.textView1);
mTextView1 = (TextView) this.findViewById(R.id.textView2);

//得到当前活动的Preferences 对象
SharedPreferences settings = getPreferences(Activity.MODE_PRIVATE);

//取得里面的数据
mbMusic = settings.getBoolean("bmusic", false);
text = settings.getString("string", text);
if(mbMusic)
{

//用来显示数据
mTextView.setText("当前的音乐状态：开");
mTextView1.setText(text);
mbMusic = true;
//mediaPlayer.start();
}else{
mTextView.setText("当前音乐状态：关");
mTextView1.setText(text);
}

}
public boolean onKeyUp(int keyCode,KeyEvent event)
{
switch(keyCode)
{

// 用来改变 mTextView的数据
case KeyEvent.KEYCODE_DPAD_UP:
mTextView.setText("当前音乐状态：开");
mbMusic = true;
//mediaPlayer.start();
break;
case KeyEvent.KEYCODE_DPAD_DOWN:
mTextView.setText("当前音乐状态：关");
mbMusic= false;
// mediaPlayer.stop();
//mediaPlayer.release();
break;
}
return true;
}
public boolean onKeyDown(int keyCode,KeyEvent event)
{
if(keyCode == KeyEvent.KEYCODE_BACK){

// 用来获得当前活动的Preferences
SharedPreferences State = getPreferences(0);

//取得编辑对象
SharedPreferences.Editor editor = State.edit();

// 编辑string类型的数据
editor.putString("string", "你爸是**呀？");

//编辑boolean类型的数据
editor.putBoolean("bmusic", mbMusic);

//最后用commit()方法来保存编辑的数据
editor.commit();
//结束程序
this.finish();

//可以不用写return
return true;
}

//这个必须写 但可以写成return true;不受影响
return super.onKeyDown(keyCode, event);
}