要想在label中使用 必须是继承于label的分类

//
//  MYlabel.m
//  MenuController
//
//  Created by 张明 on 16/3/8.
//  Copyright © 2016年 张明. All rights reserved.
//

#import "MYlabel.h"

@implementation MYlabel

- (void)awakeFromNib
{
    
    [self setup];
    
}

- (instancetype)initWithFrame:(CGRect)frame
{
    if (self = [super initWithFrame:frame]) {
        [self setup];
    }
    return self;
}

- (void)setup
{
    self.userInteractionEnabled = YES;
    
     [self addGestureRecognizer:[[UITapGestureRecognizer alloc] initWithTarget:self action:@selector(labelClick)]];
}

/*
 让label有资格成为第一响应者
 
 */
- (BOOL)canBecomeFirstResponder
{
    return YES;
}

- (void)labelClick
{
    //1.label要成为第一响应者(作用是:告诉UIMenuController支持哪些操作,这些操作如何处理)
    [self becomeFirstResponder];
    
    //2.显示MenuController
    UIMenuController *menu = [UIMenuController sharedMenuController];
    //targetRect :MenuController需要指向的矩形框
    //targetview:targetrect会以targetview的左上角为坐标原点
    
    [menu setTargetRect:self.bounds inView:self];
    [menu setMenuVisible:YES animated:YES];
    
}
/*
 label能执行哪些操作(比如copy.paste 等等)
 
 @return YES:支持这种操作
 
 */
- (BOOL)canPerformAction:(SEL)action withSender:(id)sender
{
    if (action == @selector(cut:) || action == @selector(copy:) || action == @selector(paste:)) return YES;
    
    return NO;
    
}

- (void)copy:(id)sender
{
    //将自己的文字赋值到粘贴板
    UIPasteboard *board = [UIPasteboard generalPasteboard];
    board.string = self.text;
}

- (void)cut:(id)sender
{
    //将自己的文字赋值到粘贴板
    [self copy:sender];
    
    //清空文字
    self.text = nil;
    
    
}

- (void)paste:(id)sender
{
    
    //将粘贴板的文字复制到自己身上
    UIPasteboard *board = [UIPasteboard generalPasteboard];
    
    self.text = board.string;

}

@end