Does Asynctask require a progress dialog?
No.
An asynchronous task is defined by a computation that runs on a
background thread and whose result is published on the UI thread. An
asynchronous task is defined by 3 generic types, called Params,
Progress and Result, and 4 steps, called onPreExecute, doInBackground,
onProgressUpdate and onPostExecute.
Programmatically: The progress dialog is introduced when there is a dependency on the async task to complete or reach a particular stage before there is further non-exception resulting interaction from the user.
There is a UI angle to it, which in the specified case engages the user visually or by animation which is a good practice when the app is not 'doing' anything for the user.
Android Ref:AsyncTask
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