Question

In my Activity I use a class which extends from AsyncTask and a parameter which is an instance of that AsyncTask. When I call mInstanceOfAT.execute("") everything is fine.
But the app crash when I press an update button which calls again the AsyncTask(In case the network job didnt work). Cause then appears an Exception which says

Cannot execute task: the task has
already been executed (a task can be
executed only once)

I have tried calling cancel(true) for the instance of the Asyctask, but it doesnt work either. The only solution so far it’s to create new instances of the Asyntask. Is that the correct way?

Thanks.

Answer 1

AsyncTask instances can only be used one time.

Instead, just call your task like new MyAsyncTask().execute("");

From the AsyncTask API docs:

Threading rules

There are a few threading rules that must be followed for this class to work properly:

• The task instance must be created on the UI thread.
• execute(Params…) must be invoked on the UI thread.
• Do not call onPreExecute(), onPostExecute(Result), doInBackground(Params…), onProgressUpdate(Progress…) manually.
• The task can be executed only once (an exception will be thrown if a second execution is attempted.)