iPhone : How to detect the end of slider drag?

Question

How to detect the event when the user has ended the drag of a slider pointer?

Answer 1

You can add an action that takes two parameters, sender and an event, for UIControlEventValueChanged:

[slider addTarget:self action:@selector(onSliderValChanged:forEvent:) forControlEvents:UIControlEventValueChanged]

Then check the phase of the touch object in your handler:

- (void)onSliderValChanged:(UISlider*)slider forEvent:(UIEvent*)event {     
    UITouch *touchEvent = [[event allTouches] anyObject];
    switch (touchEvent.phase) {     
        case UITouchPhaseBegan:
            // handle drag began
            break;
        case UITouchPhaseMoved:
            // handle drag moved
            break;
        case UITouchPhaseEnded:
            // handle drag ended
            break;
        default:
            break;
    }
}

Swift 4 & 5

slider.addTarget(self, action: #selector(onSliderValChanged(slider:event:)), for: .valueChanged)

@objc func onSliderValChanged(slider: UISlider, event: UIEvent) {
    if let touchEvent = event.allTouches?.first {
        switch touchEvent.phase {
        case .began:
            // handle drag began
        case .moved:
            // handle drag moved
        case .ended:
            // handle drag ended
        default:
            break
        }
    }
}

Note in Interface Builder when adding an action you also have the option to add both sender and event parameters to the action.

Answer 2

Connect Touch Up Inside and Value Changed

Answer 3

In Swift 4 you can use this function

1 Frist step:- Adding the target in slider

self.distanceSlider.addTarget(self, action: #selector(self.sliderDidEndSliding(notification:)), for: ([.touchUpInside,.touchUpOutside]))

2 Second step:- Create a function

@objc func sliderDidEndSliding(notification: NSNotification)
{
   print("Hello-->\(distanceSlider.value)")
}

Answer 4

You can use:

- (void)addTarget:(id)target action:(SEL)action 
                   forControlEvents:(UIControlEvents)controlEvents  

to detect when the touchDown and touchUp events occur in UISlider