how to show toast in WorkManager doWork()

Question

how to show toast in WorkManager do work()?

When I try, it throws

Caused by: java.lang.RuntimeException: Can't create handler inside thread that has not called Looper.prepare()

Pratik Butani · Accepted Answer · 2019-06-05T06:24:00.540

25

You can create Handler to show Toast on UI thread.

Your doWork method will be like:

@NonNull
@Override
public Result doWork() {
    Log.d(TAG, "doWork for Sync");

    Handler handler = new Handler(Looper.getMainLooper());
    handler.postDelayed(new Runnable() {
        @Override
        public void run() {
            // Run your task here
            Toast.makeText(mContext, "Testing", Toast.LENGTH_SHORT).show();
        }
    }, 1000 );

    return Result.success();
}

Note : mContext will be available in Constructor.

Hope it will help you. Thank you.

edited Jun 05 '19 at 06:24

answered Jun 03 '19 at 13:12

Pratik Butani

60,504
58
273
437

the solution works well, but if you need to run it your work on background it will not. Because it requires context, so be aware! – Nurseyit Tursunkulov Jun 05 '19 at 03:34
3

@NurseyitTursunkulov Context is available inside workers via `getApplicationContext()` anyways so it will work regardless affinity. – VPZ Nov 13 '20 at 16:37

score 0 · Answer 2 · answered Jun 13 '21 at 14:50

Also found alternative solution, worked for me as well:

@Override
public Result doWork() {
    context.getMainExecutor().execute(() -> Toast.makeText(context, "Сас ))", Toast.LENGTH_LONG).show());
    return Result.success();   // may be done with handler
}

But also i saved Context variable to the classfield

Context context;

public BackgroundWorker(Context context, WorkerParameters workerParams) {
    super(context, workerParams);
    this.context = context;
}

how to show toast in WorkManager doWork()

2 Answers2