Wrong data shown after setDisplayedValues about numberpicker HOT 3 CLOSED

I was having the exact same problem with a very erratic behavior. Found out that the component view is not reusable. Let me explain.

First, you need to have the exact order of:

numberPicker.setMinValue
numberPicker.setMaxValue
numberPicker.setDisplayedValues

If you invoke the "numberPicker.setDisplayedValues" first, which is a logic thing to do, you start getting a ArrayIndexOutOfBoundsException with a fixed index of 99. So, you do things in that order.

But the problem is when you try to reuse that same NumberPicker with different values. If the min or max value index is bigger than the displayed values list already there, you get again an ArrayIndexOutOfBoundsException.

But if the indexes are ok, the list is still all mixed up, with the selected value overlapping the other values, and sometimes even some missing values that only appear when we try to scroll through them.

The solution that I found was to set in the XML layout only a container for the NumberPicker (like a FrameLayout or something). And then, programmatically, create the NumberPicker and add it to the container. E.g.:

private void setNumberPicker(ViewGroup numberPickerContainer, String[] displayValues, String valueToSet) {
    NumberPicker numberPicker = new NumberPicker(getContext());

    numberPicker.setLayoutParams(new LinearLayout.LayoutParams(LinearLayout.LayoutParams.MATCH_PARENT, LinearLayout.LayoutParams.MATCH_PARENT));

    numberPicker.setSelectedTextColorResource(R.color.picker_selected_text_color);
    numberPicker.setSelectedTextSize(R.dimen.picker_selected_text_size);
    numberPicker.setTextColorResource(R.color.picker_text_color);
    numberPicker.setTextSize(R.dimen.picker_text_size);
    numberPicker.setDividerColorResource(android.R.color.transparent);

    final int DEFAULT_VISIBLE_ITEMS = 9;
    int itemsLength = displayValues.length;
    int numberOfVisibleItems = itemsLength < DEFAULT_VISIBLE_ITEMS ? (itemsLength + 1) : DEFAULT_VISIBLE_ITEMS;
    numberPicker.setWheelItemCount(numberOfVisibleItems);

    numberPicker.setMinValue(1);
    numberPicker.setMaxValue(displayValues.length);
    numberPicker.setDisplayedValues(displayValues);

    for (int i = 0; i < displayValues.length; i++) {
        if (displayValues[i].equals(valueToSet)) {
            numberPicker.setValue(i + 1);
            break;
        }
    }

    numberPickerContainer.removeAllViews();
    numberPickerContainer.addView(numberPicker);
}

Hope this helps others with the same problem.

from numberpicker.

+1'd the component being not reusable. I can't get it to work using any of workarounds here without at least graphical glitch (last item being on top before scrolling despite wrap around = false).

@ShawnLin013 this issue definitely should not be closed, it leads devs to believing that they're doing something wrong, so they reorder the min/max/val calls and do some weird workarounds, meanwhile it's the API here being fundamentally broken.

Don't get my wrong, I'm glad you reworked horrible original NumberPicker to point of being somewhat usable, but closing the issue just leads to people wasting time.

from numberpicker.

Hi @oenukr,
Thank you for your patch, but unfortunately there is an unacceptable side effect.
You can try the following code when received data from remote service.
I had tested it after the view is initialized 10 seconds later, and it's working correctly.

new CountDownTimer(10000, 1000) {
    @Override
    public void onTick(long millisUntilFinished) {
         // do nothing
     }

    @Override
    public void onFinish() {
        int length = 10;
        String[] numbers = new String[length];
        for (int i = 0; i < numbers.length; i++) {
            numbers[i] = String.valueOf(i);
        }
        numberPicker.setMinValue(1);
        numberPicker.setMaxValue(length);
        numberPicker.setDisplayedValues(numbers);
        numberPicker.setValue(0);
    }
}.start();

from numberpicker.