Android AsyncTask使用心得及錯誤處理-只能在主線程改變UI組件

Android AsyncTask使用心得及錯誤處理-只能在主線程改變UI組件

大家肯定都會經常使用AsyncTask這個類，特別是在網路處理中，先看改正後的代碼：這是正常的代碼：

 

class sendKeyTask extends AsyncTask{@Overrideprotected void onPostExecute(Integer resultCode) {// TODO Auto-generated method stubsuper.onPostExecute(resultCode);switch (resultCode) {case 6000:NotifyHelper.popNotifyInfo(InnerQuestionActivity.this, "使用者資訊異常", "");break;case 6001:NotifyHelper.popNotifyInfo(InnerQuestionActivity.this, "其他異常", "");break;case 6002:break;default:break;}// 隱藏IMEInputMethodManager imm = (InputMethodManager) getApplicationContext().getSystemService(Context.INPUT_METHOD_SERVICE);// 顯示或者隱藏IMEimm.toggleSoftInput(0, InputMethodManager.HIDE_NOT_ALWAYS);innerQuestionEdit.setText("");//從新重新整理new getQuestionDetailTack().execute(1);}@Overrideprotected Integer doInBackground(String... data) {// TODO Auto-generated method stubint resultCode=4001;HttpClient client= new DefaultHttpClient();HttpPost post = new HttpPost("http://diandianapp.sinaapp.com/add_key.php");StringBuilder builder = new StringBuilder(); List paramsList=new ArrayList();paramsList.add(new BasicNameValuePair("access_token", data[0]));paramsList.add(new BasicNameValuePair("user_name", data[1]));paramsList.add(new BasicNameValuePair("key_detail", data[2]));paramsList.add(new BasicNameValuePair("question_id", data[3]));for(int i=0;i可能有人會說，我讓doInBackground返回一個參數，再在onPostExecute裡面處理不是多次一舉嗎？但是，當你真的將兩部分合成後，會發現，竟然報錯了！報錯內容大體為UI內容只能在主線程更改；這是為什麼呢！
 
NotifyHelper.popNotifyInfo(InnerQuestionActivity.this, "其他異常", "");是對對話提示框的一個彈出方法封裝，這是對UI介面的操作，問題應該就出在這兒了！
我們翻開google的說明看下：
 
protected abstract Result doInBackground (Params... params)Added in API level 3
Override this method to perform a computation on a background thread. The specified parameters are the parameters passed toexecute(Params...) by the caller of this task. This method can callpublishProgress(Progress...) to publish updates on the UI thread.
Parameters