MediaRecorder & MediaPlayer ~ 個人錄音(四)

Implement 「Play」function

PersonRecordActivity.java

public class PersonRecordActivity extends Activity implements OnCompletionListener, OnErrorListener{

    static final int IDLE_STATE = 0;
    // 播放狀態以2來表示
    static final int PLAYING_STATE = 2;
    // 此值紀錄record的起始時間
    long recordingStart =0;
    MediaPlayer mPlayer = null;
    MediaRecorder mPlayer = null;

    public void onClick(View ImageButton) {
        switch (ImageButton.getId()) {
            // 當user按下play按鈕
            case R.id.ib_play:
                startPlayback();
                updateUi();
                break;
        .
        .
        .
        }
    }

    public void startPlayback() {
        try {
            if(mPlayer == null) {
                mPlayer = new MediaPlayer();
            }        
        // 欲播放檔案之完整路徑
        mPlayer.setDataSource(recordingFile.getAbsolutePath());
        // 監聽"檔案播放完"的事件
        mPlayer.setOnCompletionListener(this);
        // 監聽"檔案播放中產生錯誤"的事件
        mPlayer.setOnErrorListener(this);
        // 緩衝
        mPlayer.prepare(); 
        // 開始播放            
        mPlayer.start();
    } catch (NullPointerException e) {
        mPlayer = null;
        return;       
    } catch (IllegalArgumentException e) {
        mPlayer = null;
        return;
    } catch (IOException e) {
        mPlayer = null;
        return;
    }

        recordingStart = System.currentTimeMillis();
        setState(PLAYING_STATE);
    }

    private void setState(int state) {
        mState = state;
    }

    public void onCompletion(MediaPlayer mp) {
        // 把狀態設為IDLE
        mState = IDLE_STATE;
        stop();
    }

    public boolean onError(MediaPlayer mp, int what, int extra) {
        stop();
        return true;
    }

    // stop()的狀況有兩種, 1. 錄音狀態的stop 2.播放狀態的stop
    public void stop() {
        stopRecording();
        stopPlayback();
    }

    public void stopRecording() {
        if (mRecorder == null)
            return;

        mRecorder.stop();
        mRecorder.release();
        mRecorder = null;  

        setState(IDLE_STATE);
    }

    public void stopPlayback() {
        if (mPlayer == null)
            return;

        mPlayer.stop();
        mPlayer.release();
        mPlayer = null;

        setState(IDLE_STATE);
    }
}