TextView没有得到更新ProgressBar

Question

我想在微调控制器进度条完成后按钮单击更新TextView的文本。

public void launchRingDialog(View view) { 

     final ProgressDialog ringProgressDialog = ProgressDialog.show(MainActivity.this, "Please wait ...", "Downloading File ...", true); 
     ringProgressDialog.setCancelable(true); 
     new Thread(new Runnable() { 
      @Override 
      public void run() { 
       try { 
        String text; 
        int build_num = android.os.Build.VERSION.SDK_INT; 
        Set buildNumbers = getSharedPreferenceData(build_numbers); 
        boolean result = isPresent(buildNumbers, 
          build_num); 
        if (result) { 
         text = "Present"; 
        } else { 
         text = "Not Present"; 
        } 
        //Thread.sleep(5000); 
        System.out.println("Text After button click"); 
        System.out.println(text); 

        TextView compliance = (TextView) findViewById(R.id.compliance); 
        compliance.setText(text); 

       } catch (Exception e) { 

       } 
       ringProgressDialog.dismiss(); 
      } 
     }).start(); 
    } 
    @Override 
    public void onClick(View v) { 
     // TODO Auto-generated method stub 
     if (v.getId() == R.id.download_file) { 
      System.out.println("Inside button click"); 
      launchRingDialog(v); 
     } 
} 

在onCreate中，我检查内部编号，并将文本设置为“Present”。但是，当我做的按钮点击，sharedPreference文件被改变了，我检查，返回“不存在于当前的版本号，这是没有得到体现在TextView的。

它的线程在这里创造出了问题？

Answer 1

的问题在于你试图从另一个线程调用方法compliance.setText（text），这在Android上是不允许的，对于你想要做的事情，你应该真的使用AsyncTask而不是启动你自己的线程。类似这样的：

public void launchRingDialog(View view) { 

     final ProgressDialog ringProgressDialog = ProgressDialog.show(MainActivity.this, "Please wait ...", "Downloading File ...", true); 
     ringProgressDialog.setCancelable(true); 

     new AsyncTask<Void,Void,String>(){ 

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

       String text; 
       int build_num = android.os.Build.VERSION.SDK_INT; 
       Set buildNumbers = getSharedPreferenceData(build_numbers); 
       boolean result = isPresent(buildNumbers, 
         build_num); 
       if (result) { 
        text = "Present"; 
       } else { 
        text = "Not Present"; 
       } 

       return text; 
      } 

      @Override 
      protected void onPostExecute(String s) { 
       TextView compliance = (TextView) findViewById(R.id.compliance); 
       compliance.setText(s); 
       ringProgressDialog.dismiss(); 
      } 
     }.execute(); 
    } 

    @Override 
    public void onClick(View v) { 
     // TODO Auto-generated method stub 
     if (v.getId() == R.id.download_file) { 
      System.out.println("Inside button click"); 
      launchRingDialog(v); 
     } 
    }