AndroidアプリケーションでasyncTaskが完了した後に出力がありません

Question

このアクティビティの出力では、タイトルバーで空白の画面が表示されます。私はここで間違って何をしていますか？ asyncTaskメソッドを削除すると出力は完全に出力されますが、時間が遅れます。私を助けてください。

public class viewstoryActivity extends Activity { 
    public Context context; 

    @Override 
    public void onCreate(Bundle savedInstanceState) { 
     super.onCreate(savedInstanceState); 
     setContentView(R.layout.list); 
     context = this; 
     DownloadTask task = new DownloadTask(); 
     task.execute(); 
    } 

    public void test() { 
     try { 
      LinearLayout layout[]; 
      LinearLayout layout2[]; 
      LinearLayout layout3[]; 
      TextView name[]; 
      TextView desc[]; 
      TextView viewCount[]; 
      ImageView website[]; 
      ImageView star[]; 
      TextView category[]; 
      URL url = new URL("http://gdata.youtube.com/feeds/api/videos?start-index=1&max-results=25&vq=itsaperfectstory&orderby=relevance"); 
      DocumentBuilderFactory dbf = DocumentBuilderFactory.newInstance(); 
      DocumentBuilder db = dbf.newDocumentBuilder(); 
      Document doc = db.parse(new InputSource(url.openStream())); 
      // doc.getDocumentElement().normalize(); 
      NodeList nodeList = doc.getElementsByTagName("entry"); 
      layout = new LinearLayout[nodeList.getLength()]; 
      layout2 = new LinearLayout[nodeList.getLength()]; 
      layout3 = new LinearLayout[nodeList.getLength()]; 
      name = new TextView[nodeList.getLength()]; 
      desc = new TextView[nodeList.getLength()]; 
      viewCount = new TextView[nodeList.getLength()]; 
      website = new ImageView[nodeList.getLength()]; 
      star = new ImageView[nodeList.getLength()]; 
      category = new TextView[nodeList.getLength()]; 
      for (int i = 0; i < nodeList.getLength(); i++) { 
       Node node = nodeList.item(i); 
       layout[i] = new LinearLayout(context); 
       layout[i].setOrientation(LinearLayout.HORIZONTAL); 
       layout[i].setBackgroundResource(R.anim.bg); 
       layout[i].setLayoutParams(new LayoutParams(LayoutParams.MATCH_PARENT, 150)); 
       layout2[i] = new LinearLayout(context); 
       layout2[i].setOrientation(LinearLayout.VERTICAL); 
       layout2[i].setLayoutParams(new LayoutParams(400, 150)); 
       layout3[i] = new LinearLayout(context); 
       layout3[i].setOrientation(LinearLayout.VERTICAL); 
       layout3[i].setLayoutParams(new LayoutParams(150, 150)); 
       name[i] = new TextView(context); 
       desc[i] = new TextView(context); 
       viewCount[i] = new TextView(context); 
       website[i] = new ImageView(context); 
       star[i] = new ImageView(context); 
       category[i] = new TextView(context); 
       name[i].setPadding(10, 20, 0, 0); 
       name[i].setTextSize(16); 
       Element fstElmnt = (Element) node; 
       NodeList nameList = fstElmnt.getElementsByTagName("title"); 
       Element nameElement = (Element) nameList.item(0); 
       nameList = nameElement.getChildNodes(); 
       name[i].setText(((Node) nameList.item(0)).getNodeValue()); 
       name[i].setLines(1); 
       NodeList websiteList = fstElmnt.getElementsByTagName("media:content"); 
       Element websiteElement = (Element) websiteList.item(0); 
       websiteList = websiteElement.getChildNodes(); 
       final String url1 = websiteElement.getAttribute("url"); 
       NodeList websiteList1 = fstElmnt.getElementsByTagName("media:thumbnail"); 
       Element websiteElement1 = (Element) websiteList1.item(0); 
       String test = websiteElement1.getAttribute("url"); 
       NodeList descitem = fstElmnt.getElementsByTagName("content"); 
       Element descElement = (Element) descitem.item(0); 
       nameList = descElement.getChildNodes(); 
       desc[i].setText(((Node) nameList.item(0)).getNodeValue()); 
       desc[i].setLines(1); 
       desc[i].setTextColor(Color.DKGRAY); 
       desc[i].setPadding(10, 8, 0, 0); 
       NodeList gditem = fstElmnt.getElementsByTagName("yt:statistics"); 
       Element gdElement = (Element) gditem.item(0); 
       String view1 = gdElement.getAttribute("viewCount"); 
       viewCount[i].setText(view1 + " views"); 
       viewCount[i].setPadding(10, 8, 0, 0); 
       Bitmap bm = null; 
       URL aURL = new URL(test); 
       URLConnection conn = aURL.openConnection(); 
       conn.connect(); 
       InputStream is = conn.getInputStream(); 
       BufferedInputStream bis = new BufferedInputStream(is); 
       bm = BitmapFactory.decodeStream(bis); 
       bis.close(); 
       is.close(); // TODO: handle exception 
       website[i].setImageBitmap(bm); 
       website[i].setPadding(30, 20, 0, 0); 
       layout3[i].addView(website[i]); 
       layout2[i].addView(name[i]); 
       layout2[i].addView(desc[i]); 
       layout2[i].addView(viewCount[i]); 
       NodeList staringitem = fstElmnt.getElementsByTagName("gd:rating"); 
       if ((staringitem == null) || (staringitem.getLength() == 0)) { 
        star[i].setImageResource(R.drawable.star0); 
        layout2[i].addView(star[i]); 
       } else { 
        Element starElement = (Element) staringitem.item(0); 
        String stars = starElement.getAttribute("average"); 
        double d = Double.parseDouble(stars); 
        DecimalFormat decimalFormat = new DecimalFormat("#"); 
        stars = decimalFormat.format(d); 
        if (stars.contentEquals("1")) { 
         star[i].setImageResource(R.drawable.star1); 
         layout2[i].addView(star[i]); 
        } else if (stars.contentEquals("2")) { 
         star[i].setImageResource(R.drawable.star2); 
         layout2[i].addView(star[i]); 
        } else if (stars.contentEquals("3")) { 
         star[i].setImageResource(R.drawable.star3); 
         layout2[i].addView(star[i]); 
        } else if (stars.contentEquals("4")) { 
         star[i].setImageResource(R.drawable.star4); 
         layout2[i].addView(star[i]); 
        } else if (stars.contentEquals("5")) { 
         star[i].setImageResource(R.drawable.star5); 
         layout2[i].addView(star[i]); 
        } else if (stars.contentEquals("0")) { 
         star[i].setImageResource(R.drawable.star0); 
         layout2[i].addView(star[i]); 
        } 
       } 
       layout[i].addView(layout3[i]); 
       layout[i].addView(layout2[i]); 
       // layout.addView(category[i]); 
       // layout[i].addView(img[i]); 
       LinearLayout layout1 = (LinearLayout) findViewById(R.id.LinearLayout); 
       ((LinearLayout) layout1).addView(layout[i]); 
       layout[i].setOnClickListener(new OnClickListener() { 
        public void onClick(View v) { 
         Bundle bundle = new Bundle(); 
         bundle.putString("url", url1); 
         Intent intent = new Intent(viewstoryActivity.this, VidActivity.class); 
         intent.putExtras(bundle); 
         startActivityForResult(intent, 0); 
         overridePendingTransition(R.anim.right_slide_out, R.anim.right_slide_out); 
        } 
       }); 
      } 
     } catch (Exception e) { 
      System.out.println("XML Pasing Excpetion = " + e); 
     } 
    } 

    private class DownloadTask extends AsyncTask<String, Void, String> { 
     ProgressDialog progressDialog; 

     @Override 
     protected void onPreExecute() { 
      progressDialog = ProgressDialog.show(viewstoryActivity.this, "Progress Dialog Title Text", "Process Description Text", true); 
      // do initialization of required objects objects here 
     }; 

     @Override 
     protected String doInBackground(String... urls) { 
      test(); 
      return ""; 
     }; 

     @Override 
     protected void onPostExecute(String result) { 
      super.onPostExecute(result); 
      progressDialog.dismiss(); 
     }; 
    } 
} 

Answer 1

UIに影響を与えているあなたのすべてのタスクがないバックグラウンドスレッドでは、UIスレッド上で実行する必要があります。

は、2つのクラスレベル変数

LinearLayout container; // R.id.LinearLayout1 in your case 
LinearLayout holder; // you will initialize it in your test() method 

がfindViewById(R.id.LinearLayout1);によってonCreate()内containerを初期化し、あなたのlayout.xml内からのコンテナのレイアウトを取得取る：onPostExecute()

提案にすべてのあなたのように文

移動あなたはダウンロード後にあなたのViewsを追加したいg。 doInBackground()

から呼び出さtest()方法で今

holder

holder = new LinearLayout(this); 

としての初期化はholderに、すべてのチャイルズを追加します。

次にonPostExecute()にholder~を加えます。