iPhone:Programming UISlider to position at clicked location

Question

How to set the slider to clicked position and get the slider value on the clicked location on UISlider in iPhone programming. i know we can drag the slider to that position

Answer 1

I was using the subclassed UISlider code to listen to ValueChanged events in ios6> in order to implement a snap-to-grid type of function.

This was broken when upgrading to iOS7 as it no longer fired the UIControlEventsValueChanged. For anyone having the same problem it is fixed by adding a line in the if() as below:

-(void) touchesBegan:(NSSet *)touches withEvent:(UIEvent *)event {

    UITouch *touch = [[event allTouches] anyObject];
    CGPoint touchLocation = [touch locationInView:self];

    // if we didn't tap on the thumb button then we set the value based on tap location
    if (!CGRectContainsPoint(lastKnownThumbRect, touchLocation)) {

        self.value = self.minimumValue + (self.maximumValue - self.minimumValue) * (touchLocation.x / self.frame.size.width);
        [self sendActionsForControlEvents:UIControlEventValueChanged];
    }

    [super touchesBegan:touches withEvent:event];
}

- (CGRect)thumbRectForBounds:(CGRect)bounds trackRect:(CGRect)rect value:(float)value {

    CGRect thumbRect = [super thumbRectForBounds:bounds trackRect:rect value:value];
    lastKnownThumbRect = thumbRect;
    return thumbRect;
}

Hope it helps someone :)