Accessibility: UISlider's UIControlEventValueChanged is not posted when slider.value is set in Voice-over mode

Question

I am having a UISlider in my parent view. I want to honor the Voice-over gestures for slider movement and thus, i have implemented accessibilityIncrement and accessibilityDecrement methods as below:

- (void)accessibilityIncrement
{
     float finalValue = self.value;
    finalValue = (finalValue + 1);
    if (finalValue > self.maximumValue)
        finalValue = self.maximumValue;
    self.value = finalValue;    
}

- (void)accessibilityDecrement
{
    float finalValue = self.value;
    finalValue = (finalValue - 1);
    if (finalValue < self.minimumValue)
        finalValue = self.minimumValue;
    self.value = finalValue;

}

The issue is when I set the value of the slider (using self.value = finalValue), the selector for UIControlEventValueChanged event does not get called. Is this a Bug?

Thanks!

Avow

Figured out a work-around with the help of a friend, [self sendActionsForControlEvents:UIControlEventValueChanged]; can be used inside accessibilityIncrement and accessibilityDecrement functions to achieve the same. – Avow

Answer 1

A recommended solution for a UISlider with VoiceOver consists in using a delegate in your code with the increment and decrement methods you already use to adapt the slider value according to the knob location.

Guidance