应用程序在更改页面上停止

Question

I am working in one application where i am getting continuous response from server but when i change the page or moved to the other screen the application gets stop.I am receiving the response from server but it is not updating in listview.

I have used onResume and onPause method also but still i am receiving the error.

code;

protected class GetTask extends AsyncTask<Void, Void, Integer> {

        @Override
        protected Integer doInBackground(Void... params) {
            // TODO Auto-generated method stub
            try {
                CallReceiveMsgAPIService();
            } catch (Exception e) {
            }
            return 0;
        }

        @Override
        protected void onPostExecute(Integer result) {
            // TODO Auto-generated method stub
            super.onPostExecute(result);
            try {
                if (initiate != 1) {
                    mMessageHandle.sendEmptyMessage(0);
                    new GetTask().execute();

                    }
                } else {


                    mLiveChatList.setAdapter(adapter);
                    adapter.notifyDataSetChanged();
                    mLiveChatList.requestLayout();
                                        alert();
                }
            } catch (Exception e) {
            }

        }
    }

error:

05-10 14:14:01.213: E/AndroidRuntime(277): FATAL EXCEPTION: main
05-10 14:14:01.213: E/AndroidRuntime(277): java.lang.IllegalStateException: The content of the adapter has changed but ListView did not receive a notification. Make sure the content of your adapter is not modified from a background thread, but only from the UI thread. [in ListView(2131361857, class android.widget.ListView) with Adapter(class com.$ChatListAdapter)]
05-10 14:14:01.213: E/AndroidRuntime(277):  at android.widget.ListView.layoutChildren(ListView.java:1492)
05-10 14:14:01.213: E/AndroidRuntime(277):  at android.widget.AbsListView.onTouchModeChanged(AbsListView.java:1960)
05-10 14:14:01.213: E/AndroidRuntime(277):  at android.view.ViewTreeObserver.dispatchOnTouchModeChanged(ViewTreeObserver.java:591)
05-10 14:14:01.213: E/AndroidRuntime(277):  at android.view.ViewRoot.ensureTouchModeLocally(ViewRoot.java:2021)
05-10 14:14:01.213: E/AndroidRuntime(277):  at android.view.ViewRoot.ensureTouchMode(ViewRoot.java:2005)
05-10 14:14:01.213: E/AndroidRuntime(277):  at android.view.ViewRoot.handleMessage(ViewRoot.java:1774)
05-10 14:14:01.213: E/AndroidRuntime(277):  at android.os.Handler.dispatchMessage(Handler.java:99)
05-10 14:14:01.213: E/AndroidRuntime(277):  at android.os.Looper.loop(Looper.java:123)
05-10 14:14:01.213: E/AndroidRuntime(277):  at android.app.ActivityThread.main(ActivityThread.java:4627)
05-10 14:14:01.213: E/AndroidRuntime(277):  at java.lang.reflect.Method.invokeNative(Native Method)
05-10 14:14:01.213: E/AndroidRuntime(277):  at java.lang.reflect.Method.invoke(Method.java:521)
05-10 14:14:01.213: E/AndroidRuntime(277):  at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:868)
05-10 14:14:01.213: E/AndroidRuntime(277):  at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:626)
05-10 14:14:01.213: E/AndroidRuntime(277):  at dalvik.system.NativeStart.main(Native Method)

could anybody get me out of this ..@Thanks

Answer 1

Call adapter.notifyDataSetChanged(); after there is a change in the list to notify the listView that the contents of list have changed. This will surely solve this error.

protected class GetTask extends AsyncTask<Void, Void, Integer> {
public interface TaskListener
{
public void updateResult(Object result);
}
private TaskListener listener;
        @Override
        protected Integer doInBackground(Void... params) {
            // TODO Auto-generated method stub
            try {
                CallReceiveMsgAPIService();
            } catch (Exception e) {
            }
            return 0;
        }

        @Override
        protected void onPostExecute(Integer result) {
            // TODO Auto-generated method stub
            super.onPostExecute(result);
            try {
                if (initiate != 1) {
                    mMessageHandle.sendEmptyMessage(0);
                    new GetTask().execute();

                    }
                } else {

          listener.updateResult(result);
                    //mLiveChatList.setAdapter(adapter);
                    //adapter.notifyDataSetChanged();
                   // mLiveChatList.requestLayout();
                                      //  alert();
                }
            } catch (Exception e) {
            }

        }
    }

In activity implement this interface TaskListener and in the updateresult method do the code commented.