UIResponder API分析

介绍:

UIResponder主要用于事件响应,事件转发以方便用户交互操作

1.首先UIResponder 实现了UIResponderStandardEditActions协议,协议方法有

- (void)cut:(nullable id)sender NS_AVAILABLE_IOS(3_0);
- (void)copy:(nullable id)sender NS_AVAILABLE_IOS(3_0);
- (void)paste:(nullable id)sender NS_AVAILABLE_IOS(3_0);
- (void)select:(nullable id)sender NS_AVAILABLE_IOS(3_0);
- (void)selectAll:(nullable id)sender NS_AVAILABLE_IOS(3_0);
- (void)delete:(nullable id)sender NS_AVAILABLE_IOS(3_2);
- (void)makeTextWritingDirectionLeftToRight:(nullable id)sender NS_AVAILABLE_IOS(5_0);
- (void)makeTextWritingDirectionRightToLeft:(nullable id)sender NS_AVAILABLE_IOS(5_0);
- (void)toggleBoldface:(nullable id)sender NS_AVAILABLE_IOS(6_0);
- (void)toggleItalics:(nullable id)sender NS_AVAILABLE_IOS(6_0);
- (void)toggleUnderline:(nullable id)sender NS_AVAILABLE_IOS(6_0);

- (void)increaseSize:(nullable id)sender NS_AVAILABLE_IOS(7_0);
- (void)decreaseSize:(nullable id)sender NS_AVAILABLE_IOS(7_0);

可以配合UIMenuController实现子类控件的复制、粘贴删除等操作，也可以自定义UIMenuItem实现自己的功能,再使用时要注意- (BOOL)canBecomeFirstResponder;方法和- (BOOL)canPerformAction:(SEL)action withSender:(nullable id)sender NS_AVAILABLE_IOS(3_0);方法。具体参照UIMenuController和UIResponderStandardEditActions分析