说明：这是一个带长按复制功能的Label扩展
前按：实现该功能需要用到的类有，UIMenuItem、UIMenuController、UIPasteboard。
代码：
// .h文件
#import@interface UILabel (CopyLabel)
- (void)copyLabelText;
@end
- (void)copyLabelText{
[self setUp];
}
- (void)setUp{
self.userInteractionEnabled = YES;
[self addGestureRecognizer:[[UILongPressGestureRecognizer alloc] initWithTarget:self action:@selector(longPressAction:)]];
}
- (void)longPressAction:(UILongPressGestureRecognizer *)press{
//设置为第一响应，通过第一响应者UIMenuController可以获得支持那些操作信息
[self becomeFirstResponder];
UIMenuController *menu = [UIMenuController sharedMenuController];
UIMenuItem *copyMenu = [[UIMenuItem alloc] initWithTitle:@"复制" action:@selector(copyMenuAction)];
menu.menuItems = @[copyMenu];
[menu setTargetRect:self.bounds inView:self];
[menu setMenuVisible:YES animated:YES];
}
- (void)copyMenuAction{
if (!self.text) return;
UIPasteboard *paste = [UIPasteboard generalPasteboard];
paste.string = self.text;
}
// 用于UIMenuController显示，缺一不可
-(BOOL)canBecomeFirstResponder{
return YES;
}
// 用于UIMenuController显示，缺一不可
-(BOOL)canPerformAction:(SEL)action withSender:(id)sender{
if (action == @selector(copyMenuAction)){
return YES;
}
return NO;//隐藏系统默认的菜单项
}