Question

I’ve got a curious problem when I try to show(); my Toasts. You’ll see below two Toasts separated by a try/catch and Thread.sleep(); In this case the second Toast, toast2, will show up but toast1 will not.

If I remove the try/catch both Toasts will show up with no problem.

I’ve seen elsewhere on SO that toast.show(); makes a request on the UI Thread which can be conflicted by other operations. I’m wondering if that is the same problem I have here with the Thread.sleep(); How can I solve this problem?

Thank you

TestService.java

    ///Debug - Show a Toast
    // Toast does NOT show up
    Toast toast1 = Toast.makeText(context,"Service Started", Toast.LENGTH_SHORT);
    toast1.show();

    //Try to sleep for roughly 2 seconds
    try {
        Thread.sleep(2000);
    } catch (InterruptedException e) {
        // TODO Auto-generated catch block
        e.printStackTrace();
    }

    //Debug - Shows a Toast
    Toast toast2 = Toast.makeText(context,"Sleep completed", Toast.LENGTH_SHORT);
    toast2.show();

Answer 1

In real life, you will probably have some logic instead of just “sleep”, right?
THe right android way of, per your example, starting a service would be through executing it on a worker thread. This will make sure you won’t get an ANR.

your could would look something like:

    new AsyncTask<Void, Void, Void>() {

        @Override
        protected void onPostExecute(Void result) {
            Toast toast2 = Toast.makeText(context, "Sleep completed",
                    Toast.LENGTH_SHORT);
            toast2.show();
        }

        @Override
        protected void onPreExecute() {
            Toast toast1 = Toast.makeText(context, "Service Started",
                    Toast.LENGTH_SHORT);
            toast1.show();
        }

        @Override
        protected Void doInBackground(Void... params) {
            // Try to sleep for roughly 2 seconds
            try {
                Thread.sleep(2000);
            } catch (InterruptedException e) {
                // TODO Auto-generated catch block
                e.printStackTrace();
            }
            return null;

        }

    }.execute();