检测触摸拖动外部的结束

Question

我在一个按钮上有一个Touch Drag Outside事件，我想在用户停止拖动并再次抬起屏幕的手指时检测并运行一个方法。我找不到与按钮中匹配的事件，而touchesEnded也无效。 怎么办？

Answer 1

您应该使用touchesCancelled:withEvent:

Answer 2

You can use "PangestureRecognizer" in this case and can determine the states of gestures

if (gestureRecognizer.state == UIGestureRecognizerStateBegan) 
{

//do something

}

else if (gestureRecognizer.state == UIGestureRecognizerStateChanged) 
{

//do something

}
else if (gestureRecognizer.state == UIGestureRecognizerStateEnded)
{

//do something

}