Android File 数据存储

最新推荐文章于 2025-05-26 21:50:46 发布

原创最新推荐文章于 2025-05-26 21:50:46 发布 · 98 阅读

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文章标签：

#Android #Java #OS #UP

本文介绍了一个简单的Android应用，该应用使用MIDIPlayer类来播放背景音乐，并通过按键控制音乐的开关。此外，应用还利用Properties类保存和读取设置，确保每次打开应用时都能记住用户的音乐偏好。


package com.Aina.Android;

import java.io.IOException;

import android.content.Context;
import android.media.MediaPlayer;

public class MIDIPlayer {

	private Context mContext = null;
	private MediaPlayer mMediaPlayer = null;
	public MIDIPlayer(Context context){
		mContext = context;
	}
	public void start(){
		mMediaPlayer = MediaPlayer.create(mContext, R.raw.start);//装载资源
		mMediaPlayer.setLooping(true);//循环播放
		try {
			mMediaPlayer.prepare();
		} catch (IllegalStateException e) {
			e.printStackTrace();
		} catch (IOException e) {
			e.printStackTrace();
		}
		mMediaPlayer.start();
	}

	public void stop(){
		if(mMediaPlayer != null){
			mMediaPlayer.stop();
			mMediaPlayer.release();
		}
	}
}


package com.Aina.Android;

import java.io.FileInputStream;
import java.io.FileNotFoundException;
import java.io.FileOutputStream;
import java.io.IOException;
import java.util.Properties;

import android.app.Activity;
import android.content.Context;
import android.content.Intent;
import android.os.Bundle;
import android.view.KeyEvent;
import android.view.View;
import android.widget.Button;
import android.widget.TextView;

public class Test_File extends Activity {
	/** Called when the activity is first created. */
	private MIDIPlayer mMIDIPlayer = null;
	private boolean bm = false;
	private TextView tv = null;
	private Button btn = null;

	@Override
	public void onCreate(Bundle savedInstanceState) {
		super.onCreate(savedInstanceState);
		setContentView(R.layout.main);
		mMIDIPlayer = new MIDIPlayer(this);
		tv = (TextView) this.findViewById(R.id.TextView);
		btn = (Button) this.findViewById(R.id.Button01);
		this.load();
		if (bm) {
			mMIDIPlayer.start();
			tv.setText("当前音效：开");
		} else {
			mMIDIPlayer.stop();
			tv.setText("当前音效：关");
		}
		btn.setOnClickListener(new Button.OnClickListener() {

			@Override
			public void onClick(View v) {
				Intent intent = new Intent(Test_File.this, sg.class);
				Test_File.this.startActivity(intent);
			}

		});
	}

	@Override
	protected void onPause() {
		this.save();
		if (bm) {
			mMIDIPlayer.stop();
		}
		super.onPause();
	}

	@Override
	public boolean onKeyDown(int keyCode, KeyEvent event) {
		if (keyCode == KeyEvent.KEYCODE_DPAD_UP) {
			mMIDIPlayer.start();
			tv.setText("当前音效：开");
			bm = true;
		} else if (keyCode == KeyEvent.KEYCODE_DPAD_DOWN) {
			mMIDIPlayer.stop();
			tv.setText("当前音效：关");
			bm = false;
		}
		return super.onKeyDown(keyCode, event);
	}

	// 读取数据
	private void load() {
		Properties pro = new Properties();
		try {
			FileInputStream fin = this.openFileInput("music.cfg");// 读取文件
			try {
				pro.load(fin);// 加载到Properties属性文件里面
			} catch (IOException e) {
				e.printStackTrace();
			}
		} catch (FileNotFoundException e) {
			e.printStackTrace();
		}

		bm = Boolean.valueOf(pro.getProperty("isopen", "false"));
	}

	private String read(Context context, String filepath) {
		String data = "";
		StringBuffer sb = new StringBuffer();
		int ch = 0;
		try {
			FileInputStream in = context.openFileInput(filepath);
			while ((ch = in.read()) != -1) {
				sb.append((char) ch);
			}
			in.close();
			in = null;
			data = sb.toString();
		} catch (FileNotFoundException e) {
			e.printStackTrace();
		} catch (IOException e) {
			e.printStackTrace();
		}
		return data;
	}

	// 保存数据
	private void save() {
		Properties pro = new Properties();
		pro.put("isopen", String.valueOf(bm));
		try {
			FileOutputStream fout = this.openFileOutput("music.cfg",
					Activity.MODE_WORLD_READABLE
							| Activity.MODE_WORLD_WRITEABLE);
			pro.store(fout, "");// 写入输出流
		} catch (FileNotFoundException e) {
			e.printStackTrace();
		} catch (IOException e) {
			e.printStackTrace();
		}
	}

	private void write(Context context, String filepath, String msg) {
		try {
			FileOutputStream out = context.openFileOutput(filepath,
					context.MODE_WORLD_WRITEABLE);
			out.write(msg.getBytes());
			out.flush();
			out.close();
			out = null;
		} catch (FileNotFoundException e) {
			e.printStackTrace();
		} catch (IOException e) {
			e.printStackTrace();
		}
	}
}