java - 如何播放Environment.DIRECTORY_DOWNLOADS中的mp3文件

Question

我通过以下代码从 Url 下载了 mp3 文件并将其保存在 Environment.DIRECTORY_DOWNLOADS 中:

request.setDestinationInExternalFilesDir(MainActivity.this, Environment.DIRECTORY_DOWNLOADS,"d1.mp3");

我检查了文件可以正常下载。现在我想播放这个 d1.mp3 文件，但是当我按下播放按钮时，它没有开始播放音乐!看起来我在使用“setDataSource”时遇到了问题。如果您检查我的代码并告诉我哪里出错了，我将不胜感激。

private void initMediaPlayer()
{
    String PATH_TO_FILE = Environment.DIRECTORY_DOWNLOADS + "/d1.mp3";
    mp = new  MediaPlayer();

    try {
        mp.setDataSource(PATH_TO_FILE);
        mp.prepare();
        Toast.makeText(this, PATH_TO_FILE, Toast.LENGTH_LONG).show();
        stateMediaPlayer = stateMP_NotStarter;
        textState.setText("- IDLE -");
    } catch (IllegalArgumentException e) {
        // TODO Auto-generated catch block
        e.printStackTrace();
        Toast.makeText(this, e.toString(), Toast.LENGTH_LONG).show();
        stateMediaPlayer = stateMP_Error;
        textState.setText("- ERROR!!! -");
    } catch (IllegalStateException e) {
        // TODO Auto-generated catch block
        e.printStackTrace();
        Toast.makeText(this, e.toString(), Toast.LENGTH_LONG).show();
        stateMediaPlayer = stateMP_Error;
        textState.setText("- ERROR!!! -");
    } catch (IOException e) {
        // TODO Auto-generated catch block
        e.printStackTrace();
        Toast.makeText(this, e.toString(), Toast.LENGTH_LONG).show();
        stateMediaPlayer = stateMP_Error;
        textState.setText("- ERROR!!! -");
    }

}

public void play(View view) {
    initMediaPlayer();
    mp.start();           
}

Answer 1

您应该使用 getExternalFilesDir(Environment.DIRECTORY_DOWNLOADS)(用于应用下载)或 Environment.getExternalStoragePublicDirectory(Environment.DIRECTORY_DOWNLOADS) 获取下载文件的完整路径。