UIMenuController的使用，对UILabel拷贝以及定制菜单

1. Menu所处的View必须实现 – (BOOL)canBecomeFirstResponder, 且返回YES
这个一定要返回YES

2. Menu所处的View必须实现 – (BOOL)canPerformAction:withSender, 并根据需求返回YES或NO

3. 使Menu所处的View成为First Responder (becomeFirstResponder)

4. 定位Menu (- setTargetRect:inView:)

5. 展示Menu (- setMenuVisible:animated:)

//
//  ViewController.m
//  UIMenuController
//
//  Created by 陆巧怡 on 15/9/6.
//  Copyright © 2015年 Simon. All rights reserved.
//

#import "ViewController.h"

@interface ViewController ()
@property (nonatomic, strong) NSString *text;
@property (nonatomic, strong) UILabel *label;
@end

@implementation ViewController

- (void)viewDidLoad {
    [super viewDidLoad];
    self.label = [[UILabel alloc]initWithFrame:CGRectMake(0, 100, 300, 30)];
    self.label.text = @"点击出现UIMenuController";
    self.label.userInteractionEnabled = YES;
    [self.view addSubview:self.label];
    
    
    UITapGestureRecognizer *touch = [[UITapGestureRecognizer alloc] initWithTarget:self action:@selector(handleTap:)];
    touch.numberOfTapsRequired = 1;
    [self.label addGestureRecognizer:touch];
    
}

-(void)handleTap:(UIGestureRecognizer*) recognizer{
    //是当前的对象成为第一响应者
    [self becomeFirstResponder];
    //创建UIMenuController的控件
    UIMenuItem *flag = [[UIMenuItem alloc] initWithTitle:@"国旗" action:@selector(flag:)];
    UIMenuItem *approve = [[UIMenuItem alloc] initWithTitle:@"Approve" action:@selector(approve:)];
    UIMenuItem *deny = [[UIMenuItem alloc] initWithTitle:@"Deny" action:@selector(deny:)];
    
    UIMenuController *menu = [UIMenuController sharedMenuController];
    [menu setMenuVisible:NO];

    [menu setMenuItems:[NSArray arrayWithObjects:flag, approve, deny, nil]];
    [menu setTargetRect:self.label.frame inView:self.label.superview];
    [menu setMenuVisible:YES animated:YES];
}

#pragma mark UIMenuController 控件方法
- (void)flag:(id)sender {
    NSLog(@"国旗");
}

- (void)approve:(id)sender {
    NSLog(@"Approve");
}

- (void)deny:(id)sender {
    NSLog(@"Deny");
}
- (void)didReceiveMemoryWarning {
    [super didReceiveMemoryWarning];
}
#pragma mark 默认是为NO的。这里一定要设置成YES 要不然就不会出现
- (BOOL)canBecomeFirstResponder{
    return YES;
}

//针对于copy的实现
-(void)copy:(id)sender{
    //这里是粘贴板 可以复制文字，图片
    UIPasteboard *pboard = [UIPasteboard generalPasteboard];
    pboard.string = self.label.text;
}

-(BOOL)canPerformAction:(SEL)action withSender:(id)sender{
    
    //这里也是间接影响显示在UIMenuController的控件
    if (action == @selector(copy:)) {
        return YES;
    }else if (action == @selector(flag:)){
        return NO;
    }else if (action == @selector(approve:)){
        return YES;
    }else if (action == @selector(deny:)){
        return YES;
    }else{
        return [super canPerformAction:action withSender:sender];
    }

}

@end