Android之音乐播放(二)
package cn.itcast.audio;import java.io.File;import java.io.IOException;import android.app.Activity;import android.media.MediaPlayer;import android.os.Bundle;import android.os.Environment;import android.util.Log;import android.view.View;import android.widget.Button;import android.widget.EditText;public class PlayActivity extends Activity {private static final String TAG = "PlayActivity"; private EditText filenameText; private MediaPlayer mediaPlayer; private String filename; private int position; @Override public void onCreate(Bundle savedInstanceState) { super.onCreate(savedInstanceState); setContentView(R.layout.main); filenameText = (EditText)this.findViewById(R.id.filename); mediaPlayer = new MediaPlayer(); ButtonClickListener listener = new ButtonClickListener(); Button playButton = (Button)this.findViewById(R.id.play); Button pauseButton = (Button)this.findViewById(R.id.pause); Button resetButton = (Button)this.findViewById(R.id.reset); Button stopButton = (Button) this.findViewById(R.id.stop); playButton.setOnClickListener(listener); pauseButton.setOnClickListener(listener); resetButton.setOnClickListener(listener); stopButton.setOnClickListener(listener); Log.i(TAG, "onCreate()"); } @Overrideprotected void onRestoreInstanceState(Bundle savedInstanceState) {this.filename = savedInstanceState.getString("filename");this.position = savedInstanceState.getInt("position");super.onRestoreInstanceState(savedInstanceState);Log.i(TAG, "onRestoreInstanceState()");}@Overrideprotected void onSaveInstanceState(Bundle outState) {outState.putString("filename", filename);outState.putInt("position", position);super.onSaveInstanceState(outState);Log.i(TAG, "onSaveInstanceState()");}@Overrideprotected void onPause() {//如果突然电话到来，停止播放音乐if(mediaPlayer.isPlaying()){position = mediaPlayer.getCurrentPosition();//保存当前播放点mediaPlayer.stop();}super.onPause();}@Overrideprotected void onResume() {if(position>0 && filename!=null){//如果电话结束，继续播放音乐try {play();mediaPlayer.seekTo(position);position = 0;} catch (IOException e) {Log.e(TAG, e.toString());}}super.onResume();}@Overrideprotected void onDestroy() { mediaPlayer.release(); super.onDestroy();Log.i(TAG, "onDestroy()");}private final class ButtonClickListener implements View.OnClickListener{@Overridepublic void onClick(View v) {filename = filenameText.getText().toString();//先得到文本框中的内容Button button = (Button) v;//得到button try {switch (v.getId()) {//通过传过来的Buttonid可以判断Button的类型case R.id.play://播放play();break;case R.id.pause:if(mediaPlayer.isPlaying()){mediaPlayer.pause();button.setText(R.string.continue1);//让这个按钮上的文字显示为继续}else{mediaPlayer.start();//继续播放button.setText(R.string.pause);}break;case R.id.reset:if(mediaPlayer.isPlaying()){mediaPlayer.seekTo(0);//让它从0开始播放}else{play();//如果它没有播放，就让它开始播放}break;case R.id.stop:if(mediaPlayer.isPlaying()) mediaPlayer.stop();//如果它正在播放的话，就让他停止break;}} catch (Exception e) {//抛出异常Log.e(TAG, e.toString());}} }private void play() throws IOException {File audioFile = new File(Environment.getExternalStorageDirectory(),filename);mediaPlayer.reset();mediaPlayer.setDataSource(audioFile.getAbsolutePath());mediaPlayer.prepare();mediaPlayer.start();//播放}}?