Continuously change value of UILabel on thumb image of UISlider

Question

I have a UISlider(min 1 ,max 10). I want its thumb to have a UILabel placed on top of it that continuously updates and changes its text on moving the UISlider's thumb. So, I grabbed thumb image from the UISlider and added a UILabel to it but the label seems to overwrite itself without erasing the previous value once the thumb is moved.

- (IBAction)SnoozeSliderValueChanged:(id)sender {

    UIImageView *handleView = [_snoozeSlider.subviews lastObject];
    UILabel *label = [[UILabel alloc] initWithFrame:handleView.bounds];
    label.text = [NSString stringWithFormat:@"%0.0f", self.snoozeSlider.value];
    label.backgroundColor = [UIColor clearColor];
    label.textAlignment = NSTextAlignmentCenter;
    [handleView addSubview:label];

}

Initially,

Then, when i start dragging,

I want the label to erase the previous value and show current value as the thumb is moved. Any help is appreciated.Thanks!

Answer 1

    - (IBAction)SnoozeSliderValueChanged:(id)sender {

        //Get the Image View
        UIImageView *handleView = [_snoozeSlider.subviews lastObject];

        // Get the Slider value label
        UILabel *label = (UILabel*)[handleView viewWithTag:1000];

        // If the slider label not exist then create it and add it to the Handleview. So handle view will have only one slider value label, so no more memory issues & not needed to remove from superview.
        // Creation of object is Pain to iOS. So simply reuse it by creating only once.
        // Note that tag setting below, which will helpful to find out that view presents in later case
        if (label==nil) {

            label = [[UILabel alloc] initWithFrame:handleView.bounds];

            label.tag = 1000;

            label.backgroundColor = [UIColor clearColor];

            label.textAlignment = NSTextAlignmentCenter;

            [handleView addSubview:label];


        }

        // Update the slider value
        label.text = [NSString stringWithFormat:@"%0.0f", self.snoozeSlider.value];

    }