Question

我有一个应用程序，我想从SD卡中选择一首歌并使用按钮播放它。但是，所选歌曲的路径不会返回onActivityResult（）。它始终显示为null。我怎么能得到它？任何帮助表示赞赏。

这是我的作品

@Override
protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_main);
    buttonChoose = (Button) findViewById(R.id.buttonChoose);
    setVolumeControlStream(AudioManager.STREAM_MUSIC);
    buttonChoose.setOnClickListener(this);
}

@Override
public void onClick(View v) {

    if (v.getId() == R.id.buttonChoose) {
        System.gc();
        Intent intent = new Intent(android.content.Intent.ACTION_GET_CONTENT);
        Uri data = Uri.parse("file:///sdcard/media/audio/notifications");
        String type = "audio/mp3";
        intent.setDataAndType(data, type);
        startActivityForResult(intent, 1);
    }

}

@Override
protected void onActivityResult(int requestCode, int resultCode, Intent data) {

    if (requestCode == 1) {
        if (data != null) {
            mp = new MediaPlayer();
            mp.setAudioStreamType(AudioManager.STREAM_MUSIC);
            try {
                uri = getIntent().getData();
                if (uri != null) {
                    mp.setDataSource(getApplicationContext(), uri);
                    mp.prepare();
                    mp.start();

                    mp.start();
                    mp.setOnCompletionListener(new MediaPlayer.OnCompletionListener() {
                        @Override
                        public void onCompletion(MediaPlayer mp) {
                            mp.release();
                        }
                    });
                } else {
                    Toast.makeText(MainActivity.this, "Data is null...", Toast.LENGTH_SHORT).show();
                }

            } catch (Exception exception) {
                exception.printStackTrace();
                Toast.makeText(MainActivity.this, "Error", Toast.LENGTH_SHORT).show();
            }
        }
    }
}

Answer 1

在onActivityResult而不是uri = data.getData();

中使用uri = getIntent().getData();

Answer 2

检查AndroidManifest.xml中的权限

<uses-permission android:name="android.permission.READ_EXTERNAL_STORAGE" />

从SD卡中选择一首歌并在android中播放

2 个答案: