如何在Android中实现恢复/暂停录音？

Question

我正在构建具有恢复/暂停功能的m4a录制的Android应用程序。可能吗？如果是，请告诉我解决方案。

谢谢

Answer 1

如果您需要播放音频/视频资源，您可以使用MediaPlayer对象，如果您有特殊需要，您可以将其包装。特别是，要显示视频，您需要一个SurfaceView及其持有者。无论如何，它的工作原理如下：

假设您的媒体资源位于原始文件夹中，媒体播放器可以是这样的：

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

public class MyPlayer {

    private MediaPlayer mPlayer;
    private SurfaceHolder mSurfaceHolder;

    public void play(Context c) {

        if (mPlayer == null) {

            mPlayer = MediaPlayer.create(c, R.<YOUR RESOURCE NAME>);
            mPlayer.setDisplay(mSurfaceHolder);

            //Sets a listener to the mPlayer variable that set's it to null once the playing is finished
            mPlayer.setOnCompletionListener(new MediaPlayer.OnCompletionListener() {

                @Override
                public void onCompletion(MediaPlayer mp) {
                        stop();
                }
            });

        }
        mPlayer.start();
    }

    public void pause() {
        if (mPlayer.isPlaying()) {
            mPlayer.pause();
        }
    }

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

    public void setSurface(SurfaceHolder sh) {
      mSurfaceHolder = sh;
    }

}

播放器将被封装在片段/活动中。假设有一个xml布局，其中SurfaceView作为“屏幕”和三个用于媒体控制的按钮，您的片段将如下所示：

public class PlayerFragment extends Fragment {

    private Button mPlayButton;
    private Button mPauseButton;
    private Button mStopButton;
    private SurfaceView mSurface;
    private SurfaceHolder mHolder;
    private MyPlayer mPlayer = new MyPlayer();

    @Override
    public View onCreateView(LayoutInflater inflater, ViewGroup parent, Bundle savedInstanceState) {

        //Gets the view and sets the player to be able to play a video resource
        View v = inflater.inflate(R.layout.<YOUR XML LAYOUT>, parent, false);
        mSurface = (SurfaceView) v.findViewById(R.id.surface);
        mHolder = mSurface.getHolder();
        mHolder.setKeepScreenOn(true);
        mPlayer.setSurface(mHolder);

        //Inflates the play button and sets on it a listener (created as an anonymous class)
        mPlayButton = (Button) v.findViewById(R.id.playButton);
        mPlayButton.setOnClickListener(new View.OnClickListener() {

            @Override
            public void onClick(View v) {
            mPlayer.play(getActivity());    
            }
        });

        //Inflates the pause button and sets on it a listener (created as an anonymous class)
        mPauseButton = (Button) v.findViewById(R.id.pauseButton);
        mPauseButton.setOnClickListener(new View.OnClickListener() {

            @Override
            public void onClick(View v) {
                mPlayer.pause();    
            }
        });

        //Inflates the stop button and sets on it a listener (created as an anonymous class)
        mStopButton = (Button) v.findViewById(R.id.stopButton);
        mStopButton.setOnClickListener(new View.OnClickListener() {

            @Override
            public void onClick(View v) {
            mPlayer.stop(); 
            }
        });

        return v;
    }

    @Override
    public void onDestroy() {
        super.onDestroy();
        mPlayer.stop();
    }




}

请务必小心，在使用完媒体资源后，或在获得锁后活动/片段被销毁时，请释放媒体资源。如果不这样做，可能会影响其他应用程序或操作系统的行为。

显然，如果您需要更复杂的功能，您必须添加它们。这只是一个非常简单的播放器的示例。还要记住，可能的不兼容性可能会随着某种文件和/或设备而增加。