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UISlider and UIScrollView

Asked 2011-01-05T02:21:02.867
17

I have a UISlider as part of a view that is loaded into a UIScrollView with paging enabled. I've noticed an unexpected behavior. If the user tries to use the slider quickly (i.e. press and move) it "activates" the scroll view, causing the page to switch. However, if your press and hold for a second the slider "activates" and you can then adjust the slider value. This behavior is undesirable.

What is the best way to make the UISlider responsive when loaded into a UIScrollView? I've thought about adding a "blocker" view that just eats up touch events that is placed under the slider, but not sure if this is the best way to go about it.

iphone uiscrollview uislider
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You can subclass UIScrollView and override the method - (BOOL)touchesShouldBegin:(NSSet *)touches withEvent:(UIEvent *)event inContentView:(UIView *)view as follows:

- (BOOL)touchesShouldBegin:(NSSet *)touches withEvent:(UIEvent *)event inContentView:(UIView *)view {
    if ([view isKindOfClass:[UISlider class]]) {
        UITouch *touch = [[event allTouches] anyObject];
        CGPoint location = [touch locationInView:view];
        CGRect thumbRect;
        UISlider *mySlide = (UISlider*) view;
        CGRect trackRect = [mySlide trackRectForBounds:mySlide.bounds];
        thumbRect = [mySlide thumbRectForBounds:mySlide.bounds trackRect:trackRect value:mySlide.value];
        if (CGRectContainsPoint(thumbRect, location))
            return YES;
    }
    return NO;
}

Also Set yourScrollView.delaysContentTouches = NO; property for the scrollview.

answered 2013-05-22T12:26:11.167

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