Android running on UI thread even when using worker thread

Question

I am using a worker thread, as described here but still the code is blocking the UI. If I sleep at the beginning of the run() method, it doesn't block the UI. The thing is, it's a heavy code that runs from the onCreate method, but no matter what I do, I can't make it not block the UI. What am I doing wrong?

protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.main);
    new Thread(new Runnable() {
        @Override
        public void run() {
            for (int i = 0; i < 1000000; i++) {
                Log.d("asdf", "asdf");
            }
        }
    }).start();
}

Answer 1

You are not using an AsyncTask - which is the control Android uses to do long running processes off the UI thread.

Bottom line, use this and you will have much more success.

AsyncTask Android example

Answer 2

Use Handler to or .runOnUiThread(runnable) to call your UI thread. You can execute your thread without the Runnable as well, like this:

new Thread(){
        @Override
        public void run() {
            for (int i = 0; i < 1000000; i++) {
                Log.d("asdf", "asdf");
            }
        }
    }).start();