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我努力学习斯威夫特,这有我真的很困惑:斯威夫特UIGestureRecognizer符号
说你加入了手势:
faceView.addGestureRecognizer(UIPinchGestureRecognizer(target: faceView, action: "scale:"))
这是尺度函数:
func scale(gesture: UIPinchGestureRecognizer) {
if gesture.state == .Changed {
scale *= gesture.scale
gesture.scale = 1
}
}
为什么在缩放结束时会出现冒号(例如:“scale:”)?是否要引用scale函数接受UIPinchGestureRecognizer类型的参数这一事实?
如果是,那么冒号是如何表示该参数的?
可能重复[@selector()在Swift?](http://stackoverflow.com/questions/24007650/selector-in-swift) –
@RashwanL would'nt重复,但非常相关。还相关:[何时使用冒号与选择器](http://stackoverflow.com/questions/4953623/when-to-use-a-colon-with-a-selector) – tskulbru