爲什麼進度沒有顯示

Question

我通過php腳本和httpclient在客戶端從網站獲取數據。數據加載時，我想在操作欄中顯示進度條。問題是進度條沒有顯示。代碼如下 -

public class MainActivity extends Activity { 
    private ListView listView1; 
    private String str = null; 
    private Classification[] classification_datas; 

    @Override 
    protected void onCreate(Bundle savedInstanceState) { 
     StrictMode.setThreadPolicy(new StrictMode.ThreadPolicy.Builder() 
       .detectDiskReads().detectDiskWrites().detectNetwork() 
       .penaltyLog().build()); 
     super.onCreate(savedInstanceState); 
     requestWindowFeature(Window.FEATURE_INDETERMINATE_PROGRESS); 
     setContentView(R.layout.activity_main); 

     ActionBarUtils.setActionBar(this); 

     AsyncData data=new AsyncData(); 
     data.execute("http://kurdshopping.net/apj/category.php"); 
     try { 
      classification_datas = data.get(); 
     } catch (InterruptedException e) { 
      e.printStackTrace(); 
     } catch (ExecutionException e) { 
      e.printStackTrace(); 
     } 
     ClassificationAdapter adapter=new ClassificationAdapter(this, R.layout.listview_item_row, classification_datas); 
     listView1=(ListView) findViewById(R.id.listViewAllItems); 
     View header=(View) getLayoutInflater().inflate(
       R.layout.listview_header_row, null); 
     listView1.addHeaderView(header); 
     listView1.setAdapter(adapter); 
     listView1.setOnItemClickListener(new OnItemClickListener() { 

      @Override 
      public void onItemClick(AdapterView<?> arg0, View arg1, 
        int position, long arg3) { 
       Intent subcategory = new Intent(MainActivity.this, 
         SubCategoryActivity.class); 
       subcategory 
         .putExtra("id", classification_datas[position - 1].id); 
       startActivity(subcategory); 

      } 
     }); 

    } 

    @Override 
    public boolean onCreateOptionsMenu(Menu menu) { 
     // Inflate the menu; this adds items to the action bar if it is present. 
     getMenuInflater().inflate(R.menu.main, menu); 
     return true; 
    } 

    @Override 
    public boolean onOptionsItemSelected(MenuItem item) { 
     switch (item.getItemId()) { 
     case android.R.id.home: 
      break; 
     case R.id.action_all: 
      Intent allitemIntent = new Intent(MainActivity.this, 
        AllItemsActivity.class); 
      startActivity(allitemIntent); 
      break; 
     case R.id.action_search: 
      Intent search = new Intent(this, SearchDialogActivity.class); 
      startActivity(search); 
      break; 
     } 
     return super.onOptionsItemSelected(item); 
    } 

    private class AsyncData extends AsyncTask<String, Void, Classification[]>{ 
     private ProgressDialog pd; 
     @Override 
     protected void onPreExecute() { 
      // TODO Auto-generated method stub 
      super.onPreExecute(); 
      pd=ProgressDialog.show(MainActivity.this, "Loading. Please wait", "Loading Please wait"); 
      pd.show(); 
      setProgressBarIndeterminateVisibility(true); 
     } 

     @Override 
     protected Classification[] doInBackground(String... arg0) { 
      final Classification classification_data[] = new Classification[12]; 
      try { 
       str = CustomHttpClient 
         .executeHttpGet(arg0[0]); 
//    str = CustomHttpClient 
//      .executeHttpGet("http://kurdshopping.net/apj/category.php"); 
       JSONArray array = null; 
       array = new JSONArray(str); 
       JSONObject jdata = null; 
       jdata = array.getJSONObject(0); 

       classification_data[0] = new Classification(R.drawable.motor_icon, 
         jdata.getString("name") 
         /* res.getString(R.string.Motor) */, jdata.getInt("id")); 
       jdata = array.getJSONObject(1); 
       classification_data[1] = new Classification(R.drawable.electronics, 
         jdata.getString("name") 
         /* res.getString(R.string.Electronics) */, 
         jdata.getInt("id")); 
       jdata = array.getJSONObject(2); 
       classification_data[2] = new Classification(
         R.drawable.property_icon, jdata.getString("name") 
         /* res.getString(R.string.Property) */, jdata.getInt("id")); 
       jdata = array.getJSONObject(3); 
       classification_data[3] = new Classification(R.drawable.animal_icon, 
         jdata.getString("name") 
         /* res.getString(R.string.Animals) */, jdata.getInt("id")); 
       jdata = array.getJSONObject(4); 
       classification_data[4] = new Classification(R.drawable.house_icon, 
         jdata.getString("name") 
         /* res.getString(R.string.House) */, jdata.getInt("id")); 
       jdata = array.getJSONObject(5); 
       classification_data[5] = new Classification(R.drawable.gold, 
         jdata.getString("name")/* res.getString(R.string.Gold) */, 
         jdata.getInt("id")); 
       jdata = array.getJSONObject(6); 
       classification_data[6] = new Classification(
         R.drawable.farming_icon, jdata.getString("name") 
         /* res.getString(R.string.Farming) */, jdata.getInt("id")); 
       jdata = array.getJSONObject(7); 
       classification_data[7] = new Classification(
         R.drawable.bussines_icon, jdata.getString("name") 
         /* res.getString(R.string.Business) */, jdata.getInt("id")); 
       jdata = array.getJSONObject(8); 
       classification_data[8] = new Classification(R.drawable.sports_icon, 
         jdata.getString("name") 
         /* res.getString(R.string.Sports) */, jdata.getInt("id")); 
       jdata = array.getJSONObject(9); 
       classification_data[9] = new Classification(
         R.drawable.music_icon, 
         jdata.getString("name")/* res.getString(R.string.Music) */, 
         jdata.getInt("id")); 
       jdata = array.getJSONObject(10); 
       classification_data[10] = new Classification(
         R.drawable.fashion_icon, jdata.getString("name") 
         /* res.getString(R.string.Fashion) */, jdata.getInt("id")); 
       jdata = array.getJSONObject(11); 
       classification_data[11] = new Classification(R.drawable.jobs_icon, 
         jdata.getString("name")/* res.getString(R.string.Jobs) */, 
         jdata.getInt("id")); 
      } catch (NotFoundException e) { 
      } catch (JSONException e) { 
      } catch (Exception e) { 
       // TODO Auto-generated catch block 
       e.printStackTrace(); 
      } 
      return classification_data; 
     } 

     @Override 
     protected void onPostExecute(Classification[] result) { 
      // TODO Auto-generated method stub 
      super.onPostExecute(result); 
      pd.dismiss(); 
      setProgressBarIndeterminateVisibility(false); 
     } 

    } 
} 

我在做我的代碼錯了嗎？提前致謝。

Answer 1

public class MainActivity extends Activity { 
    private ListView listView1; 
    private String str = null; 
    private Classification[] classification_datas; 
    private ProgressDialog pd; 

，並刪除

private ProgressDialog pd; 

從的AsyncTask

，看看它是否適合你。並在preExecuteMethod