安卓：ProgressDialog外部異步類（某塊異步線程）

Question

我主要活動：

public class ChooseWriteSentenceActivity extends ActionBarActivity{ 
    protected void onCreate(Bundle savedInstanceState) { 
     super.onCreate(savedInstanceState); 
     String userName = "Zdzisiu"; 
     String password = "Ziemniak"; 
     MainServie service = new MainService(this); 
     boolean isExsist = service.findUser(String userName, String password); 
     //more code... 
    } 
} 

在我的應用程序服務使用存儲庫和jsonconsumers但簡單的代碼，我跳過他們。

public class MyService{ 
    private Context context; 
    public MyService(Context context){ 
     this.context = context 
    } 
    public boolean findUser(String userName, String password){ 
     String resultS = null; 
     try{ 
      resultS = new QueryExecutorFindUser(context).execute(userName,password).get(); 
     } 
     catch(Exception ex){ 
      ex.printStackTrace(); 
     } 
     boolean realRes = jsonConsumer(resultS).getFindUser(); 
     return realRes; 
    } 
} 

public class QueryExecutorFindUser extends AsyncTask<String,Void,String> { 


protected final String connectionUrl = "http://myWebService:44302/Service.svc/"; 

    protected ProgressDialog progressDialog; 
    protected Context curContext; 

    public QueryExecutor(Context context){ 
     curContext = context; 
    } 

    @Override 
    protected void onPreExecute() 
    { 
     super.onPreExecute(); 
     progressDialog = ProgressDialog.show(curContext,"Loading...", 
       "Loading application View, please wait...", false, false); 
    } 

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

    protected String doInBackground(String... args){ 
     String result = null; 
     String url = connectionUrl + args[0] + "/" + args[1]; 
     HttpResponse response = null; 
     HttpClient httpclient = this.getNewHttpClient(); 
     HttpGet get = new HttpGet(url); 
     get.setHeader("Accept", "application/json"); 
     get.setHeader("Content-type", "application/json"); 
     try{ 
      response = httpclient.execute(get); 
      StatusLine statusLine = response.getStatusLine(); 
      if(statusLine.getStatusCode() == HttpStatus.SC_OK){ 
       if(response != null){ 
        ByteArrayOutputStream out = new ByteArrayOutputStream(); 
        response.getEntity().writeTo(out); 
        out.close(); 
        result = out.toString(); 
       } 
      } else{ 
       throw new IOException(statusLine.getReasonPhrase()); 
      } 
     } catch(Exception ex){ 
      ex.getMessage(); 
     } finally{ 
      if(response != null){ 
       try{ 
        response.getEntity().getContent().close(); 
       } catch(Exception ex){ 
       } 
      } 
     } 

     return result; 
    } 
} 

而且進度對話框顯示，但只有後onCreatre在ChooseWriteSentenceActivity包括QueryExecutor doInBacground（...）的所有代碼完成（所以它在同一時間幾乎消失）。它看起來像......等待與QueryExecutorFindUser.doInBackground（）線程，它是像同步運行（？），我認爲，因爲當我調試代碼onPreExecute（）正確運行（並開始之前doInBackground（...））和progressDialog如果我從QueryExecutorFindUser中刪除擴展AsyncTask，並在主要活動中使用此擴展創建私有類（並從包含服務的onCreated（）運行所有代碼。）.isShowing（）== true（但屏幕上不顯示:(）在這個私人的類.doInBackground（...））findUser（）它工作okey。

我更喜歡progressDialog在一個地方沒有在所有主要活動（實踐中的cource的使用QueryExecutor所有查詢不僅findUser）我不知道我做錯了什麼，我花了整整一天的時間沒有結果:(

Answer 1

對話框綁定到Activity並最終必須由一個託管。所以直到你的應用程序的活動被創建，對話框將不會顯示。