NumberPicker showing wrong value after setValue()

Question

I was trying to create a NumberPicker that would meet my needs, but I stumbled upon something and I don\'t understand what it is.

The behavior is simple, I have three nu

Answer 1

I had a similar issue. I was using the scrollBy() method to set the value of the number picker programmatically and on two of the values, wrong numbers were shown. After some investigation I realized that there was some code in the onTouch of the NumberPicker, which was not being called when setting values programmatically.

So I simulate a touch right after I set a value.

public void changeValueByOne(final boolean increment) {

    int scrollStep = getHeight() / 3;

    scrollBy(0, increment ? scrollStep : (-1 * scrollStep));

    simulateTouchHack();
}

private void simulateTouchHack() {
    MotionEvent motionEventDown = MotionEvent.obtain(
            SystemClock.uptimeMillis(),
            SystemClock.uptimeMillis() + 100,
            MotionEvent.ACTION_DOWN,
            getWidth() / 2,
            getHeight() / 2,
            0
    );

    dispatchTouchEvent(motionEventDown);

    MotionEvent motionEventUp = MotionEvent.obtain(
            SystemClock.uptimeMillis() + 200,
            SystemClock.uptimeMillis() + 300,
            MotionEvent.ACTION_UP,
            getWidth() / 2,
            getHeight() / 2,
            0
    );

    dispatchTouchEvent(motionEventUp);
}

Answer 2

Calling invalidate() on the NumberPicker might help. I called it from Fragment.onViewCreated and so far so good