NullPointerException을 던지는 AsyncTask의 ProgressDialog?

Question

http 서버에서 json 피드를로드하는 동안 ProgressDialog을 표시하려고합니다. doInBackground 및 onPostExecute에 NullPointerException이 있습니다. AsyncTask을 오해하지 않은 경우 onPostExecute에 최종 코드가 실행됩니다. 내 잘못은 어디 있니? 여기 내 활동 코드입니다 :

public class ResultInput extends Activity { 

    int count = 0; 
    String mainUrl; 
    String[] product_pict_part; 
    InputStream is = null; 
    private ProgressDialog pd; 
    String TAG = "meinDebug"; 
    ParseEan parse_code; 
    String readProductNameEan; 
    ImageView productPic; 
    String productName; 
    Drawable drawable; 
    TextView product_name; 
    TextView text_level; 
    int productLevel; 

    private Context context; 

    // private MyProgressDialog dialog; 
    @Override 
    public void onCreate(Bundle icicle) { 
     super.onCreate(icicle); 
     new ProgressTask(ResultInput.this).execute(); 
    } 

    private InputStream fetch(String urlString) throws MalformedURLException, 
      IOException { 
     DefaultHttpClient httpClient = new DefaultHttpClient(); 
     HttpGet request = new HttpGet(urlString); 
     HttpResponse response = httpClient.execute(request); 
     return response.getEntity().getContent(); 
    } 

    private class ProgressTask extends AsyncTask<String, Void, Boolean> { 
     private ProgressDialog dialog; 
     private Activity activity; 

     // private List<Message> messages; 
     public ProgressTask(Activity activity) { 
      this.activity = activity; 
      context = activity; 
      dialog = new ProgressDialog(context); 
     } 

     /** progress dialog to show user that the backup is processing. */ 

     /** application context. */ 

     protected void onPreExecute() { 
      this.dialog.setMessage("Progress start"); 
      this.dialog.show(); 
     } 

     @Override 
     protected void onPostExecute(final Boolean success) { 
      pd.dismiss(); 
      productPic.setImageDrawable(drawable); 

      Log.i(TAG, "Picture URL " + mainUrl); 
      product_name.setText(productName); 

      if (productLevel == 1) { 
       text_level.setText("helal"); 
      } else if (productLevel == 2) { 
       text_level.setText("mittel"); 
      } else if (productLevel == 3) { 
       text_level.setText("haram"); 
      } else if (productLevel == 4) { 
       text_level.setText("in analyse"); 
      } 

      if (dialog.isShowing()) { 
       dialog.dismiss(); 
      } 

      if (success) { 
       Toast.makeText(context, "OK", Toast.LENGTH_LONG).show(); 
      } else { 
       Toast.makeText(context, "Error", Toast.LENGTH_LONG).show(); 
      } 
     } 

     protected Boolean doInBackground(final String... args) { 
      try { 
       mainUrl = "http://nur-efsan.de/websHalalCheck/public/image/index/dir/"; 
       product_name = (TextView) findViewById(R.id.produkt_name); 
       text_level = (TextView) findViewById(R.id.text_level); 
       productPic = (ImageView) findViewById(R.id.productpic); 
       productName = parse_code.parseJSONPost("data", "name", 
         readProductNameEan); 
       String productPicture = parse_code.parseJSONPost("data", 
         "image", readProductNameEan); 
       productLevel = Integer.parseInt(parse_code.parseJSONPost(
         "data", "levelId", readProductNameEan)); 

       product_pict_part = productPicture.split("/"); 
       mainUrl = mainUrl + product_pict_part[0] + "/name/" 
         + product_pict_part[1]; 

       try { 
        is = fetch(mainUrl); 
       } catch (MalformedURLException e) { 
        // TODO Auto-generated catch block 
        e.printStackTrace(); 
       } catch (IOException e) { 
        // TODO Auto-generated catch block 
        e.printStackTrace(); 
       } 
       drawable = Drawable.createFromStream(is, "src"); 

       return true; 
      } catch (Exception e) { 
       Log.e("tag", "error", e); 
       return false; 
      } 
     } 

    } 

} 

Answer 1

OnPostExecute 방법에

dialog.dismiss(); 

대신

pd.dismiss(); 

둘째

당신은 안 doinbackground 메서드가 UI 스레드가 아니기 때문에 doInBackgroud (...) 메서드에서 TextView 또는 imageview (productname, testview ...)를 참조합니다. onPostExecute method...에서

So give refrence in onCreate method and then call asyncTask와 setValue에 답장을

Answer 2

많은 감사를! 내 코드를 설명해 주면 코드가 바뀝니다! 그리고 난 내 콘텐츠보기 : 내 마지막 코드를 설정하는 것을 잊지 있습니다

package com.halal.helalcheck; 

import java.io.IOException; 
import java.io.InputStream; 
import java.net.MalformedURLException; 

import org.apache.http.HttpResponse; 
import org.apache.http.client.methods.HttpGet; 
import org.apache.http.impl.client.DefaultHttpClient; 

import android.app.Activity; 
import android.app.ProgressDialog; 
import android.content.Context; 
import android.graphics.drawable.Drawable; 
import android.os.AsyncTask; 
import android.os.Bundle; 
import android.util.Log; 
import android.widget.ImageView; 
import android.widget.TextView; 

public class ResultInput extends Activity { 

    int count = 0; 
    String mainUrl; 
    String[] product_pict_part; 
    InputStream is = null; 
    String TAG = "meinDebug"; 
    ParseEan parse_code = new com.halal.helalcheck.ParseEan(); 
    String readProductNameEan; 
    ImageView productPic; 
    String productName; 
    Drawable drawable; 
    TextView product_name; 
    TextView text_level; 
    int productLevel; 


    private Context context; 

    // private MyProgressDialog dialog; 
    @Override 
    public void onCreate(Bundle icicle) { 
     super.onCreate(icicle); 
     setContentView(R.layout.resultwindow); 

     mainUrl = "http://nur-efsan.de/websHalalCheck/public/image/index/dir/"; 
     product_name = (TextView) findViewById(R.id.produkt_name); 
     text_level = (TextView) findViewById(R.id.text_level); 
     productPic = (ImageView) findViewById(R.id.productpic); 


     new ProgressTask(ResultInput.this).execute(); 


    } 

    private InputStream fetch(String urlString) throws MalformedURLException, 
      IOException { 
     DefaultHttpClient httpClient = new DefaultHttpClient(); 
     HttpGet request = new HttpGet(urlString); 
     HttpResponse response = httpClient.execute(request); 
     return response.getEntity().getContent(); 
    } 

    private class ProgressTask extends AsyncTask<String, Void, Boolean> { 
     private ProgressDialog dialog; 
     private Activity activity; 

     public ProgressTask(Activity activity) { 
      this.activity = activity; 
      context = activity; 
      dialog = new ProgressDialog(context); 
     } 

     /** progress dialog to show user that the backup is processing. */ 

     /** application context. */ 

     @Override 
     protected void onPreExecute() { 
      this.dialog.setMessage("Checking Product"); 
      this.dialog.show(); 
     } 

     @Override 
     protected void onPostExecute(final Boolean success) { 
      drawable = Drawable.createFromStream(is, "src"); 
      productPic.setImageDrawable(drawable); 
      Log.i(TAG, "Picture URL " + mainUrl); 
      product_name.setText(productName); 

      if (productLevel == 1) { 
       text_level.setText("helal"); 
      } else if (productLevel == 2) { 
       text_level.setText("mittel"); 
      } else if (productLevel == 3) { 
       text_level.setText("haram"); 
      } else if (productLevel == 4) { 
       text_level.setText("in analyse"); 
      } 

      if (dialog.isShowing()) { 
       dialog.dismiss(); 
      } 

     } 

     @Override 
     protected Boolean doInBackground(final String... args) { 
      try { 
       Bundle b = getIntent().getExtras(); 
       String ean_code = b.getString("barcodestring"); 


       String readProductNameEan = parse_code.readProductEan(ean_code); 
       Log.i(TAG, readProductNameEan); 
       productName = parse_code.parseJSONPost("data", "name", readProductNameEan); 
       Log.i(TAG, productName); 

       productLevel = Integer.parseInt(parse_code.parseJSONPost("data", "levelId", readProductNameEan)); 

       String productPicture = parse_code.parseJSONPost("data", "image", readProductNameEan); 
       product_pict_part = productPicture.split("/"); 
       mainUrl = mainUrl + product_pict_part[0] + "/name/" + product_pict_part[1]; 

       try { 
        is = fetch(mainUrl); 
       } catch (MalformedURLException e) { 
        // TODO Auto-generated catch block 
        e.printStackTrace(); 
       } catch (IOException e) { 
        // TODO Auto-generated catch block 
        e.printStackTrace(); 
       } 


       return true; 
      } catch (Exception e) { 
       Log.e("tag", "error", e); 
       return false; 
      } 
     } 

    } 

}