How to raise a toast in AsyncTask, I am prompted to used the Looper

I have tasks completed by AsyncTask in background. At some point I need to issue a Toast that something is completed.

I've tried and I failed because Caused by: java开发者_JAVA百科.lang.RuntimeException: Can't create handler inside thread that has not called Looper.prepare()

How can I do that?

onPostExecute - executes on UI thread or publishProgress(); in your doinbackground and

protected void onProgressUpdate(Integer... progress) {
}

http://developer.android.com/reference/android/os/AsyncTask.html

you can Toast inside doInBackground

add this code where you want to Toast appear

runOnUiThread(new Runnable() {
public void run() {

    Toast.makeText(<your class name>.this, "Cool Ha?", Toast.LENGTH_SHORT).show();
    }
});

You can also use runOnUiThread method to manipulate your UI from background threads.

If you want to use Toast You should use this method : onProgressUpdate()

protected Integer doInBackground(Void...Params) {
   int check_point = 1;
   publishProgress(check_point);
   return check_point;
}

protected void onProgressUpdate(Integer integers) {
  if(integers == 1) {
    Toast.makeText(classname.this, "Text", 0).show(); 
}

If you want to display the Toast from the background thread you'll have to call runOnUiThread from doInBackground. I don't believe there's another way.

Edit: I take that back. I think you can implement onProgressUpdate, which runs on the UI thread, to show the Toast and make calls to publishProgress from doInBackground.

If you want to display the Toast in doInBackground, you can use it in the OnPostExecute method of AsyncTask.

protected void onPostExecute(String file_url) {    
   Toast.makeText(getApplicationContext(),"Your Message", Toast.LENGTH_LONG).show();

   pDialog.dismiss();//dismiss the progress dialouge
}