Question

在我的应用程序中，我将播放来自URL的音乐。所以还需要一些时间播放音频，因为它是通过流媒体。我想在等待MediaPlayer播放/开始时实现ProgressDialog。

以下是播放音频的方法： public void playMedia（String songIndex）{

            ProgressDialog pDialog;
            pDialog = new ProgressDialog(context);
            pDialog.setMessage("Loading. . . ");
            pDialog.setCancelable(false);
            pDialog.show();

            Uri songUri = Uri.parse(songIndex);
                    try {
                        mp.setDataSource(context, songUri);
                        mp.setAudioStreamType(AudioManager.STREAM_MUSIC);
                        mp.prepare();

                    } catch (IllegalArgumentException e) {
                        e.printStackTrace();
                    } catch (IllegalStateException e) {
                        e.printStackTrace();
                    } catch (IOException e) {
                        e.printStackTrace();
                    }finally{
                        pDialog.dismiss();
                    }

                    if(mp!=null)
                        mp.start();
        }

这就是我尝试实现它的方式。但它没有用。我有这样的例外：

        08-27 19:48:13.896: E/InputEventReceiver(8798): Exception dispatching input event.
        08-27 19:48:13.896: E/MessageQueue-JNI(8798): Exception in MessageQueue callback: handleReceiveCallback
        08-27 19:48:13.906: E/MessageQueue-JNI(8798): android.view.WindowManager$BadTokenException: Unable to add window -- token null is not for an application
        08-27 19:48:13.906: E/MessageQueue-JNI(8798):   at android.view.ViewRootImpl.setView(ViewRootImpl.java:599)
        08-27 19:48:13.906: E/MessageQueue-JNI(8798):   at android.view.WindowManagerImpl.addView(WindowManagerImpl.java:326)
        08-27 19:48:13.906: E/MessageQueue-JNI(8798):   at android.view.WindowManagerImpl.addView(WindowManagerImpl.java:224)
        08-27 19:48:13.906: E/MessageQueue-JNI(8798):   at android.view.WindowManagerImpl$CompatModeWrapper.addView(WindowManagerImpl.java:149)
        08-27 19:48:13.906: E/MessageQueue-JNI(8798):   at android.app.Dialog.show(Dialog.java:285)
        08-27 19:48:13.906: E/MessageQueue-JNI(8798):   at com.app.adapters.MyRowAdapter.playMedia(MyRowAdapter.java:126)
        08-27 19:48:13.906: E/MessageQueue-JNI(8798):   at com.app.adapters.MyRowAdapter$2$4.onTouch(MyRowAdapter.java:522)
        08-27 19:48:13.906: E/MessageQueue-JNI(8798):   at android.view.View.dispatchTouchEvent(View.java:7185)
        08-27 19:48:13.906: E/MessageQueue-JNI(8798):   at android.view.ViewGroup.dispatchTransformedTouchEvent(ViewGroup.java:2280)
        08-27 19:48:13.906: E/MessageQueue-JNI(8798):   at android.view.ViewGroup.dispatchTouchEvent(ViewGroup.java:2023)
        08-27 19:48:13.906: E/MessageQueue-JNI(8798):   at android.view.ViewGroup.dispatchTransformedTouchEvent(ViewGroup.java:2280)
        08-27 19:48:13.906: E/MessageQueue-JNI(8798):   at android.view.ViewGroup.dispatchTouchEvent(ViewGroup.java:2023)
        08-27 19:48:13.906: E/MessageQueue-JNI(8798):   at android.view.ViewGroup.dispatchTransformedTouchEvent(ViewGroup.java:2280)
        08-27 19:48:13.906: E/MessageQueue-JNI(8798):   at android.view.ViewGroup.dispatchTouchEvent(ViewGroup.java:2023)
        08-27 19:48:13.906: E/MessageQueue-JNI(8798):   at android.view.ViewGroup.dispatchTransformedTouchEvent(ViewGroup.java:2280)
        08-27 19:48:13.906: E/MessageQueue-JNI(8798):   at android.view.ViewGroup.dispatchTouchEvent(ViewGroup.java:2023)

还有其他方法可以实现吗？我应该把这个放在哪里？提前谢谢。

Answer 1

如果你引用了getApplicationContext（），那么你在这里使用的上下文对象pDialog = new ProgressDialog(context);将不起作用。

而是尝试将其替换为，像这样的活动上下文，

 pDialog = new ProgressDialog(ActivityName.this);

Answer 2

    Use Async Task:

     private class MediaPlayer extends AsyncTask<String, Void, String> {

            @Override
            protected String doInBackground(String... params) {
                     Uri songUri = Uri.parse(songIndex);
                        try {
                            mp.setDataSource(context, songUri);
                            mp.setAudioStreamType(AudioManager.STREAM_MUSIC);
                            mp.prepare();

                        } catch (IllegalArgumentException e) {
                            e.printStackTrace();
                        } catch (IllegalStateException e) {
                            e.printStackTrace();
                        } catch (IOException e) {
                            e.printStackTrace();
                        }
return mp;
            }        

            @Override
            protected void onPostExecute(String result) {             
            }

            @Override
            protected void onPreExecute() {
    ProgressDialog pDialog;
                pDialog = new ProgressDialog(context);
                pDialog.setMessage("Uploading file. . . ");
                pDialog.setCancelable(false);
                pDialog.show();
            }

            @Override
            protected void onProgressUpdate(Void... values) {
            }
        }

Android - MediaPlayer流媒体在播放前显示进度对话框

2 个答案: