获取所有当前的 UITouch，包括未更新的 UITouch

Question

所以我正在做自定义手势识别，我遇到了麻烦。我需要监控所有当前的触摸，但touchesBegan、touchesEnded、touchesMoved 和touchesCancelled 都只给我他们正在监控的触摸。我需要对所有的触摸进行计算，不管它们是否被监控。我已经进行了一些研究，并看到了自己监控触摸的建议，但对我来说并不顺利。这是我的代码：

-(void)touchesBegan:(NSSet *)touches withEvent:(UIEvent *)event {
    /* Called when a touch begins */
    [myTouches unionSet:touches];
}
-(void)touchesMoved:(NSSet *)touches withEvent:(UIEvent *)event {

    NSArray *objects = [myTouches allObjects];

    for (UITouch *touch in touches) {
        for (UITouch *touch2 in objects) {
            if (CGPointEqualToPoint([touch2 locationInView:self.view], [touch previousLocationInView:self.view])) {
                [myTouches removeObject:touch2];
                [myTouches addObject:touch];
            }
        }
    }
}
-(void)touchesCancelled:(NSSet *)touches withEvent:(UIEvent *)event {
    [myTouches minusSet:touches];
}

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

    [myTouches minusSet:touches];

    NSArray *objects = [myTouches allObjects];

    for (UITouch *touch in touches) {
        for (UITouch *touch2 in objects) {
            if (CGPointEqualToPoint([touch2 locationInView:self.view], [touch previousLocationInView:self.view])) {
                [myTouches removeObject:touch2];
            }
        }
    }
}

我想要的：myTouches 应该是屏幕上所有触摸的准确表示。 我得到了什么：myTouches 不断增长，尽管有时来自事件的触摸被正确注册为与myTouches 中的触摸相同。我还做了一个测试，我对touchesBegan 中注册的触摸次数进行整数计数，并减去touchesEnded 中注册的触摸次数，结果总是为正数，这意味着注册的触摸次数多于结束的次数。请帮忙！

Answer 1

尝试 UIApplication 的子类来监控应用程序中的所有触摸。

    @interface MyUIApplication : UIApplication

然后在MyUIApplication中使用事件sendEvent

    - (void)sendEvent:(UIEvent *)event {

        [super sendEvent:event];
        NSSet *allTouches = [event allTouches];
        if ([allTouches count] > 0) {

             //To get phase of a touch
             UITouchPhase phase = ((UITouch *)[allTouches anyObject]).phase;
             if (phase == UITouchPhaseBegan){

                 //Do the stuff
             }
             //also you can use UITouchPhaseMoved, UITouchPhaseEnded,
             // UITouchPhaseCancelled and UITouchPhaseStationary
        }
    }

别忘了在 main 中添加类

    int main(int argc, char *argv[])
    {
          @autoreleasepool {
                return UIApplicationMain(argc, argv, NSStringFromClass([MyUIApplication class]), NSStringFromClass([AppDelegate class]));
          }
    }