Changing an Image resource

Question

When I'm clicking on a button, I want to change an Image view to different picture, to wait 3 seconds, and to change it again to another picture (without clicking again).

1 click -> change picture -> wait 3 seconds -> change picture.

This is my code:

northLight.setImageResource(R.drawable.red_and_yellow);

try {
     TimeUnit.MILLISECONDS.sleep(3000);
} catch (InterruptedException e) {}

northLight.setImageResource(R.drawable.green);

While I'm running the program, when I'm actually clicking the button, the program ignores the first setImage and changes it straight to the second setImage (to the green).

How can I solve this?

Answer 1

You can try using a Handler to wait and change the image. When your button gets clicked, change your image and run the handler with a delay of 3 seconds.

//Call this method when your button is clicked
public void changeImage() {
    northLight.setImageResource(R.drawable.red_and_yellow);

    Handler handler = new Handler();
    handler.postDelayed(new Runnable() {
        @Override
        public void run() {
            northLight.setImageResource(R.drawable.green);
        }
    }, 3000);
}