how to handle 1 to 3 fingers swipe gesture in iOS

问题:

I use the following code to handle 1 finger swipe in my code:

UISwipeGestureRecognizer *swipe = [[UISwipeGestureRecognizer alloc] initWithTarget:self action:@selector(handleViewsSwipe:)];
    [swipe setDirection:UISwipeGestureRecognizerDirectionLeft];
    [swipe setDelaysTouchesBegan:YES];
    [[self view] addGestureRecognizer:swipe];

I know i can add the following line to make it handle 2 fingers swipe:

 [swipe setNumberOfTouchesRequired:2];

However when I add the above code 1 finger swipe is no longer detected since the number of touches required is now 2. What can I do to make my code work for 1, 2 or 3 fingers swipe?

I tried using the following code but this doesn't do what I want to do.

UIPanGestureRecognizer *panRecognizer = [[UIPanGestureRecognizer alloc] initWithTarget:self action:@selector(handleViewsSwipe:)];
    [panRecognizer setMinimumNumberOfTouches:1];
    [panRecognizer setMaximumNumberOfTouches:3];
    [panRecognizer setDelaysTouchesBegan:YES];
    [[self view] addGestureRecognizer:panRecognizer];
    [panRecognizer release];

Thank you.

回答1:

In your handleViewsSwipe you can get the numberOfTouches property from the gesture recognizer.

- (void)handleViewsSwipe:(UISwipeGestureRecognizer *)recognizer {
    NSUInteger touches = recognizer.numberOfTouches;
    switch (touches) {
        case 1:
            break;
        case 2:
            break;
        case 3:
            break;
        default:
            break;
    }
}

Just switch the same method for what to do depending on how many touches you get.

回答2:

Add three swipe gesture recognizers to your view:

for (int i = 1; i <= 3; ++i) {
    UISwipeGestureRecognizer *swipe = [[UISwipeGestureRecognizer alloc] initWithTarget:self action:@selector(handleViewsSwipe:)];
    swipe.numberOfTouchesRequired = i;
    swipe.direction = UISwipeGestureRecognizerDirectionLeft;
    swipe.delaysTouchesBegan = YES;
    [self.view addGestureRecognizer:swipe];
}

Worked for me.