Way to make a UIButton continuously fire during a press-and-hold situation?

问题

You know how Mario just keeps running to the right when you press and hold the right-button on the D-Pad? In the same manner, I want my UIButton to continuously fire its action for the duration that it is held down. Is this possible for a UIButton? If not, is this possible to do with a UIImageView by overriding a touch handling method in a certain way? Actually, before trying to do get this done with UIButton I had some UIImageViews (Arranged to function as a D-Pad) that were checked by touch handling methods but things started to get messy so I thought this could be done easier with UIButton and thus switched over. Anybody who knows how to get recognition of a continuous, stationary (not-moved) down-touch, please share.

回答1:

Don't use a button, use multi-touch and NSTimer:

Make a view-local NSTimer object inside your interface, then use it to start/cancel the timer

-(void)movePlayer:(id)sender {
   <Code to move player>
}

-(void)touchesBegan:(NSSet*)touches  withEvent:(UIEvent*)event {
    timer = [NSTimer scheduledTimerWithTimeInterval:0.3 target:self selector:@selector(movePlayer:) userInfo:nil repeats:YES];
}

-(void)touchesEnded:(NSSet*)touches  withEvent:(UIEvent*)event {
   if (timer != nil) 
      [timer invalidate];
      timer = nil;
}

-(void)touchesMoved:(NSSet*)touches  withEvent:(UIEvent*)event {
    if (timer != nil) {
       [timer invalidate];
       timer = nil;
    }
}

This way, you can repeat the event at a predefined interval, and not have to rely on a button, and get the repeat behaviour you're looking for. Note the touchesMoved trigger - if they move their finger, this cancels the timer, and the player stops moving.

回答2:

You can also do similar to what is shown in the previous answer and still use a UIButton.

Just have the timer started on the "Touch Down" and have the timer stopped on either "Touch Up Inside" or "Touch Up Outside".

Personally, I like using UIButtons because they offer some built in visual enhancements you don't have to code on your own.

回答3:

For me the following works:

1. Create a button.
2. Create 2 methods (stop touching and start touching) either in view controller or to a subclass.
3. Add 3 Control Events. Touch Up Inside and Touch Drag Exit that both of them go to stop touching method and Touch Down goes with start touching method.
4. When start touching method invokes we should start an NSTimer with interval approximately 0.2 (it's up to you how fast you would like to be invoked), repeat true and as a selector a method that you want to be invoked (having the actual stuff you want to execute when user hits the button).
5. When stop touching method invokes we should invalidate timer (.invalidate()) and assign timer as nil.

That's all!

回答4:

And Now for Something Completely Different:
ReactiveCocoa 6.

self.button.reactive
    .controlEvents([.touchDown])
    .observeValues { button in
        SignalProducer.timer(interval: .milliseconds(500), on: QueueScheduler.main)
            .take(until: button.reactive.controlEvents([.touchDragOutside, .touchDragExit, .touchUpInside, .touchUpOutside, .touchCancel]).map { _ in return })
            .prefix(value: Date())
            .startWithValues { date in
                NSLog("\(date)")
            }
        }

来源：https://stackoverflow.com/questions/903114/way-to-make-a-uibutton-continuously-fire-during-a-press-and-hold-situation