安卓：使用網頁

-3

我是一個學習者和開發Android應用播放實時流顯示在媒體播放器當前曲目信息。除1個問題外，它工作正常。我想顯示當前正在播放的曲目的標題，可在網頁上找到。用於此目的的我已經使用一個TextView並試圖利用異步任務和稱爲包含一個可運行在異步任務與我可以在30處的間隔更新的TextView的文本的方法seconds.In可運行我稱爲它加載的網頁的方法並將其內容作爲字符串提供。安卓：使用網頁

問題：當它試圖更新的TextView，應用程序崩潰的文本。感謝提前。

以下是我的代碼：

import java.io.IOException; 
import android.app.Activity; 
import android.media.AudioManager; 
import android.media.MediaPlayer; 
import android.os.Bundle; 
import android.view.View; 
import android.view.View.OnClickListener; 
import android.widget.Button; 
import android.widget.Toast; 
import android.app.ProgressDialog; 
import android.media.MediaPlayer.OnPreparedListener; 
import android.os.Handler; 
import java.net.URLConnection; 
import java.net.URL; 
import java.io.InputStream; 
import java.io.BufferedReader; 
import java.io.InputStreamReader; 
import android.util.Log; 
import java.net.MalformedURLException; 
import android.widget.TextView; 
import android.os.AsyncTask; 

public class MusicAndroidActivity extends Activity { 



static MediaPlayer mPlayer; 
    Button buttonPlay; 
    Button buttonStop; 
    Button buttonPause; 
    public TextView txtMessage; 
    private StringBuilder response; 
    private String text="***"; 
    ProgressDialog progDailog; 
    private final static int INTERVAL = 1000 * 30; //2 minutes 
    Handler mHandler; 
    int length=0; 
    String url = "http://www.s8.voscast.com:9630/;stream.mp3"; 
    private final Handler handler = new Handler(); 
    @Override 
    public void onCreate(Bundle savedInstanceState) { 
     super.onCreate(savedInstanceState); 
     setContentView(R.layout.main); 

     buttonStop = (Button) findViewById(R.id.stop); 
     txtMessage=(TextView)findViewById(R.id.txtMessage); 
     buttonStop.setEnabled(false); 
     buttonPause=(Button) findViewById(R.id.pause); 
     buttonPause.setEnabled(false); 
     buttonPlay = (Button) findViewById(R.id.play); 

     buttonPlay.setOnClickListener(new OnClickListener() { 

      public void onClick(View v) { 

       mPlayer = new MediaPlayer(); 
       mPlayer.setAudioStreamType(AudioManager.STREAM_MUSIC); 
       try { 
        buttonPlay.setEnabled(false); 
        buttonStop.setEnabled(true); 
        buttonPause.setEnabled(true); 
        //txtMessage.setText("Loading..."); 
        progDailog = ProgressDialog.show(MusicAndroidActivity.this, "", "Buffering ... \n It can take upto 1 Minute, depending upon your internet speed", true); 
        mPlayer.setDataSource(url); 
       } catch (IllegalArgumentException e) { 
        Toast.makeText(getApplicationContext(), "You might not set the URI correctly!", Toast.LENGTH_LONG).show(); 
       } catch (SecurityException e) { 
        Toast.makeText(getApplicationContext(), "You might not set the URI correctly!", Toast.LENGTH_LONG).show(); 
       } catch (IllegalStateException e) { 
        Toast.makeText(getApplicationContext(), "You might not set the URI correctly!", Toast.LENGTH_LONG).show(); 
       } catch (IOException e) { 
        e.printStackTrace(); 
       } 
       try { 

        mPlayer.setOnPreparedListener(new OnPreparedListener() { 

         public void onPrepared(MediaPlayer mPlayer) { 
          // TODO Auto-generated method stub 
          mPlayer.start(); 
          progDailog.dismiss(); 
          LoadWebPageASYNC task = new LoadWebPageASYNC(); 
          task.execute(new String[]{"http://khilare.com/swltest/sms.html"}); 

         } 
        }); 
        mPlayer.prepareAsync(); 
       } catch (IllegalStateException e) { 
        Toast.makeText(getApplicationContext(), "You might not set the URI correctly!", Toast.LENGTH_LONG).show(); 
       } //catch (IOException e) { 
       //Toast.makeText(getApplicationContext(), "You might not set the URI correctly!", Toast.LENGTH_LONG).show(); 
       //} 

      } 

     }); 



     buttonStop.setOnClickListener(new OnClickListener() { 

      public void onClick(View v) { 
       // TODO Auto-generated method stub 
       if(mPlayer!=null && mPlayer.isPlaying()){ 
        mPlayer.stop(); 
        buttonPlay.setEnabled(true); 
        buttonStop.setEnabled(false); 
        buttonPause.setEnabled(false); 
       } 
      } 
     }); 

     buttonPause.setOnClickListener(new OnClickListener() { 

      public void onClick(View v) { 
       // TODO Auto-generated method stub 
       if(mPlayer!=null && mPlayer.isPlaying()){ 
        mPlayer.pause(); 
        length=mPlayer.getCurrentPosition(); 
        buttonPause.setText("Resume"); 
        //buttonPlay.setEnabled(true); 
        buttonStop.setEnabled(true); 
        buttonPlay.setEnabled(false); 
        //sapp(); 
        //getHTML(); 
        //txtMessage.setText(text); 
        txtMessage.setText(text); 
       } 
       else { 
       //mPlayer.seekTo(length); 
        mPlayer.start(); 
       // mPlayer.seekTo(length); 
        buttonPause.setText("Pause"); 

       } 
      } 
     }); 

    } 

    protected void onDestroy() { 
     super.onDestroy(); 
     // TODO Auto-generated method stub 
     if (mPlayer != null) { 
      mPlayer.release(); 
      mPlayer = null; 
     } 
    } 



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

     @Override 
     protected String doInBackground(String... urls) { 
      getHTML(); 
      //sapp(); 
      txtMessage.setText(text); 
      return null; 
     } 
    } 
    private void sapp() 
    { 
     //Runnable updater1 = new Runnable() { 
      handler.postDelayed(new Runnable() { 
       //@Override 
       public void run() { 
        getHTML(); 
        txtMessage.setText(text); 
       } 
      }, INTERVAL); 


      /*public void run() { 
       getHTML(); 
       txtMessage.setText(text); 
      } 
     };*/ 
     //handler.post(updater1); 
    } 
    private void getHTML() 
    { 
     try { 
      URLConnection connection = new URL("http://khilare.com/swltest/sms.html").openConnection(); 
      connection.setRequestProperty("Accept-Charset", "UTF-8"); 
      InputStream responseStream = connection.getInputStream(); 

      BufferedReader br = new BufferedReader(new InputStreamReader(responseStream)); 
      response = new StringBuilder(); 
      String line; 
      line = br.readLine(); 
      { 
       response.append(line); 
      } 
      text = response.toString(); 
      //txtMessage.setText(text); 
      //Log.i("Output", text); 
     } catch (MalformedURLException e) { 
      txtMessage.setText(e.getMessage()); 
      e.printStackTrace(); 
     } catch (IOException e) { 
      txtMessage.setText(e.getMessage()); 
      e.printStackTrace(); 
     } 
     //textStreamed.setText(text); 
    } 

}

這裏是logcat的：

java.lang.SecurityException: Permission denial: writing to settings requires android.permission.WRITE_SETTINGS 
      at com.android.providers.settings.SettingsProvider.callFromPackage(SettingsProvider.java:645) 
      at android.content.ContentProvider$Transport.call(ContentProvider.java:279) 
      at android.content.ContentProviderNative.onTransact(ContentProviderNative.java:273) 
      at android.os.Binder.execTransact(Binder.java:388) 
      at dalvik.system.NativeStart.run(Native Method) 
05-29 10:56:45.772  302-302/? E/Parcel﹕ Reading a NULL string not supported here. 
05-29 10:56:45.772  302-302/? E/Parcel﹕ Reading a NULL string not supported here. 
05-29 10:56:48.462  302-302/? E/Parcel﹕ Reading a NULL string not supported here. 
05-29 10:56:48.462  302-302/? E/Parcel﹕ Reading a NULL string not supported here. 
05-29 10:56:50.702  302-302/? E/Parcel﹕ Reading a NULL string not supported here. 
05-29 10:56:50.702  302-302/? E/Parcel﹕ Reading a NULL string not supported here. 
05-29 10:56:50.712  302-302/? E/Parcel﹕ Reading a NULL string not supported here. 
05-29 10:56:50.712  302-302/? E/Parcel﹕ Reading a NULL string not supported here. 

05-29 10:57:01.772 28164-28569/com.prgguru.example E/AndroidRuntime﹕ FATAL EXCEPTION: AsyncTask #1 
    java.lang.RuntimeException: An error occured while executing doInBackground() 
      at android.os.AsyncTask$3.done(AsyncTask.java:299) 
      at java.util.concurrent.FutureTask.finishCompletion(FutureTask.java:352) 
      at java.util.concurrent.FutureTask.setException(FutureTask.java:219) 
      at java.util.concurrent.FutureTask.run(FutureTask.java:239) 
      at android.os.AsyncTask$SerialExecutor$1.run(AsyncTask.java:230) 
      at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1080) 
      at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:573) 
      at java.lang.Thread.run(Thread.java:841) 
    Caused by: android.view.ViewRootImpl$CalledFromWrongThreadException: Only the original thread that created a view hierarchy can touch its views. 
      at android.view.ViewRootImpl.checkThread(ViewRootImpl.java:5969) 
      at android.view.ViewRootImpl.invalidateChildInParent(ViewRootImpl.java:921) 
      at android.view.ViewGroup.invalidateChild(ViewGroup.java:4276) 
      at android.view.View.invalidate(View.java:10552) 
      at android.view.View.invalidate(View.java:10507) 
      at android.widget.TextView.checkForRelayout(TextView.java:6531) 
      at android.widget.TextView.setText(TextView.java:3789) 
      at android.widget.TextView.setText(TextView.java:3643) 
      at android.widget.TextView.setText(TextView.java:3618) 
      at com.prgguru.example.MusicAndroidActivity$LoadWebPageASYNC.doInBackground(MusicAndroidActivity.java:158) 
      at com.prgguru.example.MusicAndroidActivity$LoadWebPageASYNC.doInBackground(MusicAndroidActivity.java:152) 
      at android.os.AsyncTask$2.call(AsyncTask.java:287) 
      at java.util.concurrent.FutureTask.run(FutureTask.java:234) 
            at android.os.AsyncTask$SerialExecutor$1.run(AsyncTask.java:230) 
            at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1080) 
            at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:573) 
            at java.lang.Thread.run(Thread.java:841)

來源

2015-05-29 SJSSoft

你的logcat在哪裏？ –

對不起，我錯過了。現在我添加了logcat，請檢查。 – SJSSoft

你的'MusicAndroidActivity $ LoadWebPageASYNC'在哪裏？ –

我知道了。

我使用了一個TimeTask，它調用一個方法UpdateGUI（）;每10秒鐘有。這種方法「UpdateGUI（）;」進一步調用一個方法「getHTML（）;」這加載網頁的內容，以字符串文本。另外這個方法調用通過myRunnable在

myHandler.post(myRunnable);

和myRunnable設置的TextView的文本txtMessage

要完全理解的過程將myHandler，請仔細閱讀this Article

代碼現在是：

import java.io.IOException; 
import android.app.Activity; 
import android.media.AudioManager; 
import android.media.MediaPlayer; 
import android.os.Bundle; 
import android.view.View; 
import android.view.View.OnClickListener; 
import android.widget.Button; 
import android.widget.Toast; 
import android.app.ProgressDialog; 
import android.media.MediaPlayer.OnPreparedListener; 
import android.os.Handler; 
import java.net.URLConnection; 
import java.net.URL; 
import java.io.InputStream; 
import java.io.BufferedReader; 
import java.io.InputStreamReader; 
import android.util.Log; 
import java.net.MalformedURLException; 
import android.widget.TextView; 
import java.util.TimerTask; 
import java.util.Timer; 

public class MusicAndroidActivity extends Activity { 

    static MediaPlayer mPlayer; 
    Button buttonPlay; 
    Button buttonStop; 
    Button buttonPause; 
    public TextView txtMessage; 
    private StringBuilder response; 
    private String text="***"; 
    ProgressDialog progDailog; 
    final Handler myHandler = new Handler(); 
    int length=0; 
    String url = "http://www.example.com:port/;stream.mp3"; 
    @Override 
    public void onCreate(Bundle savedInstanceState) { 
     super.onCreate(savedInstanceState); 
     setContentView(R.layout.main); 
     buttonStop = (Button) findViewById(R.id.stop); 
     txtMessage=(TextView)findViewById(R.id.txtMessage); 
     buttonStop.setEnabled(false); 
     buttonPause=(Button) findViewById(R.id.pause); 
     buttonPause.setEnabled(false); 
     buttonPlay = (Button) findViewById(R.id.play); 

     buttonPlay.setOnClickListener(new OnClickListener() { 
      public void onClick(View v) { 
       mPlayer = new MediaPlayer(); 
       mPlayer.setAudioStreamType(AudioManager.STREAM_MUSIC); 
       try { 
        buttonPlay.setEnabled(false); 
        buttonStop.setEnabled(true); 
        buttonPause.setEnabled(true); 
        progDailog = ProgressDialog.show(MusicAndroidActivity.this, "", "Buffering ... \n It can take upto 1 Minute, depending upon your internet speed", true); 
        mPlayer.setDataSource(url); 
       } catch (IllegalArgumentException e) { 
        Toast.makeText(getApplicationContext(), "You might not set the URI correctly!", Toast.LENGTH_LONG).show(); 
       } catch (SecurityException e) { 
        Toast.makeText(getApplicationContext(), "You might not set the URI correctly!", Toast.LENGTH_LONG).show(); 
       } catch (IllegalStateException e) { 
        Toast.makeText(getApplicationContext(), "You might not set the URI correctly!", Toast.LENGTH_LONG).show(); 
       } catch (IOException e) { 
        e.printStackTrace(); 
       } 
       try { 
        mPlayer.setOnPreparedListener(new OnPreparedListener() { 
          public void onPrepared(MediaPlayer mPlayer) { 
          // TODO Auto-generated method stub 
          mPlayer.start(); 
          progDailog.dismiss(); 
         } 
        }); 
        mPlayer.prepareAsync(); 
        Timer myTimer = new Timer();  // Declared Timer 
        myTimer.schedule(new TimerTask() { // Started Time Task, it will repeat as per given duration (Ours is 1000 or 10 Second) 
         @Override 
         public void run() { 
          UpdateGUI(); // Called Method UdateGUI 
         }     // v 
        }, 0, 10000);   // After Every 10 Seconds 

       } catch (IllegalStateException e) { 
        Toast.makeText(getApplicationContext(), "You might not set the URI correctly!", Toast.LENGTH_LONG).show(); 
       } 
      } 
     }); 

     buttonStop.setOnClickListener(new OnClickListener() { 
      public void onClick(View v) { 
       // TODO Auto-generated method stub 
       if(mPlayer!=null && mPlayer.isPlaying()){ 
        mPlayer.stop(); 
        buttonPlay.setEnabled(true); 
        buttonStop.setEnabled(false); 
        buttonPause.setEnabled(false); 
       } 
      } 
     }); 

     buttonPause.setOnClickListener(new OnClickListener() { 
      public void onClick(View v) { 
       if(mPlayer!=null && mPlayer.isPlaying()){ 
        mPlayer.pause(); 
        length=mPlayer.getCurrentPosition(); 
        buttonPause.setText("Play"); 
        buttonStop.setEnabled(true); 
        buttonPlay.setEnabled(false); 
       } 
       else { 
        mPlayer.start(); 
        buttonPause.setText("Pause"); 
       } 
      } 
     }); 

    } 

    protected void onDestroy() { 
     super.onDestroy(); 
     // TODO Auto-generated method stub 
     if (mPlayer != null) { 
      mPlayer.release(); 
      mPlayer = null; 
     } 
    } 

    private void UpdateGUI() { 
     getHTML(); 
     myHandler.post(myRunnable); // Posted MyRunnable to myHandler 
    } 

    final Runnable myRunnable = new Runnable() { 
     public void run() { 
      txtMessage.setText(text);  //Set txtMessage's value to text (text is a string declared above) 
     } 
    }; 

    private void getHTML() 
    { 
     try { 
      URLConnection connection = new URL("http://example.com/stats/index.php").openConnection(); 
      connection.setRequestProperty("Accept-Charset", "UTF-8"); 
      InputStream responseStream = connection.getInputStream(); 
      BufferedReader br = new BufferedReader(new InputStreamReader(responseStream)); 
      response = new StringBuilder(); 
      String line; 
      line = br.readLine(); 
      { 
       response.append(line); 
      } 
      text = response.toString(); 
     } catch (MalformedURLException e) { 
      txtMessage.setText(e.getMessage()); 
      e.printStackTrace(); 
     } catch (IOException e) { 
      txtMessage.setText(e.getMessage()); 
      e.printStackTrace(); 
     } 
    } 
}

來源

2015-05-30 22:32:39 SJSSoft

安卓：使用網頁

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