Android: How can I pass parameters to AsyncTask's onPreExecute()?

Question

I use an AsyncTask for loading operations that I implemented as an inner class. In onPreExecute() I show a loading dialog which I then hide again in onPostExecute(). But for some of the loading operations I know in advance that they will finish very quickly so I don't want to display the loading dialog. I wanted to indicate this by a boolean parameter that I could pass to onPreExecute() but apparently for some reason onPreExecute() doesn't take any parameters. The obvious workaround would probably be to create a member field in my AsyncTask or in the outer class which I would have to set before every loading operation but that does not seem very elegant. Is there a better way to do this?

Answer 1

Creating the member field in your subclass is the way to go.

Elegant doesn't mean this time you have to change how base classes define methods.

Answer 2

You can override the constructor. Something like:

private class MyAsyncTask extends AsyncTask<Void, Void, Void> {

    public MyAsyncTask(boolean showLoading) {
        super();
        // do stuff
    }

    // doInBackground() et al.
}

Then, when calling the task, do something like:

new MyAsyncTask(true).execute(maybe_other_params);

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Edit: this is more useful than creating member variables because it simplifies the task invocation. Compare the code above with:

MyAsyncTask task = new MyAsyncTask();
task.showLoading = false;
task.execute();