【iOS】Touch Drag Inside 和 Touch Drag Outside、Touch Drag Enter、Touch Drag Exit的区别

Touch Drag Inside：手指在控件窗口内拖动

Touch Drag Outside：手指在控件窗口外拖动

Touch Drag Enter：手指从控件窗口外部拖动到内部

Touch Drag Exit：手指从控件窗口内部拖动到外部

[依据] 来自Apple官方文档 UIControlEvents：

UIControlEventTouchDragInside：An event where a finger is dragged inside the bounds of the control.

UIControlEventTouchDragOutside：An event where a finger is dragged just outside the bounds of the control.

UIControlEventTouchDragEnter：An event where a finger is dragged into the bounds of the control.

UIControlEventTouchDragExit：An event where a finger is dragged from within a control to outside its bounds.