的AsyncTask沒有功能以及doinbackground

Question

這裏的問題是，在此之前我把所有的代碼下的onCreate（）;但加載時間超過10秒，它將顯示空白屏幕，直到屏幕完全加載。所以我將一些代碼移到了doInBackground。但我面對它的onCreate（下不會發生一些問題），讓我們看看現在的代碼：

String photoURL1; 
@Override 
    protected void onCreate(Bundle savedInstanceState) 
    { 
     super.onCreate(savedInstanceState); 
     setContentView(R.layout.app_details); 

    tvDescription = (TextView)findViewById(R.id.tvDescription); 

    tvTitle = (TextView)findViewById(R.id.tvTitle); 
    tvDeveloper = (TextView)findViewById(R.id.tvDeveloper); 

    rbRating = (RatingBar)findViewById(R.id.rbRating); 

    ivLogo = (ImageView)findViewById(R.id.ivLogo); 
    ivPhoto1 = (ImageView)findViewById(R.id.ivPhoto1); 
    ivPhoto2 = (ImageView)findViewById(R.id.ivPhoto2); 
    ivPhoto3 = (ImageView)findViewById(R.id.ivPhoto3); 

    new loadPage().execute(null, null, null); 
} 

public class loadPage extends AsyncTask<String, Integer, Void> { 
     private ProgressDialog pdia; 

    @Override 
    protected void onPreExecute(){ 
     super.onPreExecute(); 
     pdia = new ProgressDialog(AppDetails.this); 
     pdia.setMessage("Loading..."); 
     pdia.show(); 
     } 

    @Override 
    protected Void doInBackground(String... aurl) { 
     SoapObject Request = new SoapObject (NAMESPACE, METHOD_NAME); 

     Request.addProperty("title", getIntent().getExtras().getString("xdaTitle")); 

     SoapSerializationEnvelope soapEnvelope = new SoapSerializationEnvelope(SoapEnvelope.VER11); 

     soapEnvelope.dotNet = true; 
     soapEnvelope.setOutputSoapObject(Request); 

     AndroidHttpTransport aht = new AndroidHttpTransport(URL); 

     try 
     { 
      aht.call(SOAP_ACTION, soapEnvelope); 
      SoapObject resultString = (SoapObject) soapEnvelope.getResponse(); 

      for(int i =0; i<resultString.getPropertyCount(); i++) 
      { 
       SoapObject array = (SoapObject) resultString .getProperty(i); 

       title = array.getProperty(1).toString(); 
       developer = array.getProperty(3).toString();  

         //load images  
       photoURL1 = array.getProperty(5).toString(); //get logo url 


       BitmapFactory.Options bmOptions; 
       bmOptions = new BitmapFactory.Options(); 
       bmOptions.inSampleSize = 1;   

      } 
     } 
     catch(Exception e){            
     }   

     return null; 
    } 

    @Override 
    protected void onProgressUpdate(Integer... progress2) { 

    } 


     @Override 
     protected void onPostExecute(Void unused) { 
      tvTitle.setText(title); 
      tvDeveloper.setText(developer); 
      BitmapFactory.Options bmOptions; 
      bmOptions = new BitmapFactory.Options(); 
      bmOptions.inSampleSize = 1; 

      Bitmap bmLogo = LoadImage(photoURL1, bmOptions); 
      ivLogo.setImageBitmap(bmLogo); 
      pdia.dismiss(); 
     } 

這是問題所在。

• 我tvTitle只顯示前3個字符，tvDeveloper僅顯示7〜8個字符（tvtitle和tvDeveloper是一個TextView）
• 力關閉，如果我從doInBackground移動圖像加載器onPostExecute發生。

=======更新：我應該在哪裏停車這個代碼？ =================

MyI = new Intent(Intent.ACTION_VIEW); 
      MyI.setAction(android.content.Intent.ACTION_VIEW); 
      MyI.setDataAndType(Uri.parse("file:///sdcard/MaxApps/" + apkURL.toString()), "application/vnd.android.package-archive"); 

      MyPI = PendingIntent.getActivity(getApplicationContext(), 0, MyI, 0); 
      MyNM = (NotificationManager)getSystemService(Context.NOTIFICATION_SERVICE); 

      Intent intent = new Intent(getApplicationContext(), AppDetails.class); 
      intent.putExtra("xdaTitle", title); 
      final PendingIntent pendingIntent = PendingIntent.getActivity(getApplicationContext(), 0, intent, 0); 

      notification = new Notification(R.drawable.logo, "Downloading...", System.currentTimeMillis()); 
      notification.flags = notification.flags | Notification.FLAG_ONGOING_EVENT; 
      notification.contentView = new RemoteViews(getApplicationContext().getPackageName(), R.layout.downloadapk); 
      notification.contentIntent = pendingIntent; 
      notification.contentView.setImageViewResource(R.id.imgIcon, R.drawable.save); 
      notification.contentView.setTextViewText(R.id.tvText, "Downloading " + apkURL); 
      notification.contentView.setViewVisibility(R.id.pbStatus, View.VISIBLE); 
      notification.contentView.setProgressBar(R.id.pbStatus, 100, progress, false);   
      notificationManager = (NotificationManager) getApplicationContext().getSystemService(getApplicationContext().NOTIFICATION_SERVICE); 

Answer 1

你不能在後臺線程改變UI。

的的AsyncTask有一個更好的選擇，更新，同時下載的用戶界面，這是使用publishProgress()

你需要在你的代碼的一些變化這樣來實現它。

 @Override 
     protected Void doInBackground(String... aurl) { 

       for(int i =0; i<resultString.getPropertyCount(); i++) 
       {      
        String logo_URL = array.getProperty(5).toString(); //get logo url 
        bmLogo = LoadImage(logo_URL, bmOptions); 
        String photo1_URL = array.getProperty(6).toString(); 
        bmPhoto1 = LoadImage(photo1_URL, bmOptions); 
        String photo2_URL = array.getProperty(7).toString(); 
        bmPhoto2 = LoadImage(photo2_URL, bmOptions); 
        String photo3_URL = array.getProperty(8).toString(); 
        bmPhoto3 = LoadImage(photo3_URL, bmOptions); 
        publishProgress(null); 
       } 
      } 
      catch(Exception e){            
      }    

      return null; 
     } 

     @Override 
     protected void onProgressUpdate(Integer... progress2) { 
      ivLogo.setImageBitmap(bmLogo); 
      ivPhoto1.setImageBitmap(bmPhoto1); 
      ivPhoto2.setImageBitmap(bmPhoto2); 
      ivPhoto3.setImageBitmap(bmPhoto3); 
     } 

Answer 2

其實，

ivLogo.setImageBitmap(bmLogo); 
ivPhoto1.setImageBitmap(bmPhoto1); 
ivPhoto2.setImageBitmap(bmPhoto2); 
ivPhoto3.setImageBitmap(bmPhoto3); 

這些線doInBackground()事業的問題。因爲您正嘗試從工作線程（非UI線程）更新MainUI線程。

你不能從AsyncTaskdoInBackground()更新MainUI所以不如把這個UI更新代碼的AsyncTaskonPostExecute()。