我如何禁用touchesBegan：多点触摸？

Question

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

I am currently getting 1 object in

touches 

when I do a tap with two fingers simultaneously (holding option key and clicking on the simulator). I believe this is because I haven't enabled the

multipleTouchEnabled 

property of the attached view. I want to make it so that I don't register this event for multi-touches.

Looking into the issue, it seems like it would work if I enable multipleTouchEnabled, and then do

if ([touches count] > 1) {
    return;
}

in my

touchesBegan:

However, this seems strange to me in that I am ENABLING multipleTouchEnabled to DISABLE multiple touches, and am worried if there will be side-effects. Is there a better way to solve my problem?

Answer 1

You should just be able to disable the multitouch property on the view , in IB you have to actually go over to the side panel and click on the thing that says view next to files owner to get it and then uncheck it, or you could do it in code in viewdidload:

self.view.multiTouchEnabled = NO;

Answer 2

First add a gesture recognizer to your view:

UITapGestureRecognizer *multipleTouches = [[UITapGestureRecognizer alloc] initWithTarget:self action:@selector(handleMultiTap:)];
multipleTouches.numberOfTouchesRequired = 2;
[yourViewName addGestureRecognizer:multipleTouches];
[multipleTouches release];

Hope it will help you.

Answer 3

You could use a gesture recognizer, this is probably more readbale than the touches delegate even if your code works:

UITapGestureRecognizer *gestureRecognizer = [[UITapGestureRecognizer alloc] initWithTarget:self action:@selector(myAction:)];
gestureRecognizer.numberOfTouchesRequired = 2;

Answer 4

If it is compulsory to use NSTouches then you can use the following methods to get the desired task achieve.

 [view setMultipleTouchEnabled:NO]; [view setExclusiveTouch:YES]; 

more over you can play with

setMultipleTouchEnabled:

by keeping

view's setExclusiveTouch to YES

Answer 5

您可以使用此行来避免某个点的多次触摸，为您的视图设置独占触摸“是”。

[self.view setExclusiveTouch:YES];