android - 如何在 Android 中播放音频时显示 MediaController？

Question

如何在播放音频文件时显示 MediaController？我正在创建 MediaController 的实例并调用它的 show() 方法，但它没有显示。有谁能帮我解决这个问题吗？

Answer 1

这是一个使用 MediaPlayer 和 MediaController 播放音频的 Activity 示例。

import android.app.Activity;
import android.media.MediaPlayer;
import android.os.Bundle;
import android.os.Handler;
import android.util.Log;

import android.media.MediaPlayer.OnPreparedListener;
import android.view.MotionEvent;
import android.widget.MediaController;
import android.widget.TextView;

import java.io.IOException;

public class AudioPlayer extends Activity implements OnPreparedListener, MediaController.MediaPlayerControl{
  private static final String TAG = "AudioPlayer";

  public static final String AUDIO_FILE_NAME = "audioFileName";

  private MediaPlayer mediaPlayer;
  private MediaController mediaController;
  private String audioFile;

  private Handler handler = new Handler();

  public void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.audio_player);

    audioFile = this.getIntent().getStringExtra(AUDIO_FILE_NAME);
    ((TextView)findViewById(R.id.now_playing_text)).setText(audioFile);

    mediaPlayer = new MediaPlayer();
    mediaPlayer.setOnPreparedListener(this);

    mediaController = new MediaController(this);

    try {
      mediaPlayer.setDataSource(audioFile);
      mediaPlayer.prepare();
      mediaPlayer.start();
    } catch (IOException e) {
      Log.e(TAG, "Could not open file " + audioFile + " for playback.", e);
    }

  }

  @Override
  protected void onStop() {
    super.onStop();
    mediaController.hide();
    mediaPlayer.stop();
    mediaPlayer.release();
  }

  @Override
  public boolean onTouchEvent(MotionEvent event) {
    //the MediaController will hide after 3 seconds - tap the screen to make it appear again
    mediaController.show();
    return false;
  }

  //--MediaPlayerControl methods----------------------------------------------------
  public void start() {
    mediaPlayer.start();
  }

  public void pause() {
    mediaPlayer.pause();
  }

  public int getDuration() {
    return mediaPlayer.getDuration();
  }

  public int getCurrentPosition() {
    return mediaPlayer.getCurrentPosition();
  }

  public void seekTo(int i) {
    mediaPlayer.seekTo(i);
  }

  public boolean isPlaying() {
    return mediaPlayer.isPlaying();
  }

  public int getBufferPercentage() {
    return 0;
  }

  public boolean canPause() {
    return true;
  }

  public boolean canSeekBackward() {
    return true;
  }

  public boolean canSeekForward() {
    return true;
  }
  //--------------------------------------------------------------------------------

  public void onPrepared(MediaPlayer mediaPlayer) {
    Log.d(TAG, "onPrepared");
    mediaController.setMediaPlayer(this);
    mediaController.setAnchorView(findViewById(R.id.main_audio_view));

    handler.post(new Runnable() {
      public void run() {
        mediaController.setEnabled(true);
        mediaController.show();
      }
    });
  }
}

这是可以与上面的代码一起使用的布局:

<?xml version="1.0" encoding="utf-8"?>

<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
              android:id="@+id/main_audio_view"
              android:layout_width="fill_parent"
              android:layout_height="wrap_content"
              android:layout_gravity="center"
              android:orientation="vertical">
  <TextView
    android:layout_width="wrap_content"
    android:layout_height="wrap_content"
    android:layout_gravity="center"
    android:text="Now playing:"
    android:textSize="25sp"
    android:textStyle="bold"
    />
  <TextView
    android:id="@+id/now_playing_text"
    android:layout_width="wrap_content"
    android:layout_height="wrap_content"
    android:layout_marginTop="20dip"
    android:layout_marginLeft="10dip"
    android:layout_marginRight="10dip"
    android:layout_gravity="center"
    android:text="Now playing.."
    android:textSize="16sp"
    android:textStyle="italic"
    />
</LinearLayout>