iOS中UIMenuController使用

UIMenuController提供了弹出菜单功能，能实现剪切，复制，粘贴，选着，全选和删除的功能，用户也可以添加自定义菜单项。

默认情况下，UITextField，UITextView，UIWebView已经支持UIMenuController。

UITextView *textView = [[UITextView alloc] initWithFrame:self.view.bounds];
textView.editable = NO;
textView.text = @“ASDFASDF”;
[self.view addSubview:textView];

    
UIMenuController *menu = [UIMenuController sharedMenuController];
UIMenuItem *menuItem = [[UIMenuItem alloc] initWithTitle:@"Share" action:@selector(onShareClick:)];
menu.menuItems = [NSArray arrayWithObject:menuItem];

• canBecomeFirstResponder

让控件具备成为第一响应者的资格

• canPerformAction:(SEL)action withSender:(id)sender

通过第一响应者的这个方法告诉UIMenuController可以显示什么内容 

//监听自己的定义事件
- (BOOL)canPerformAction:(SEL)action withSender:(id)sender {
    if(action == @selector(onShareClick:)) {
        if (textView.selectedRange.length>0) {
            return YES;
        }
    }
    return NO;
}

- (BOOL)canBecomeFirstResponder {
    return true;

}

让其他控件也支持UIMenuController

设置控件允许交互

UILabel *label = [UILabel alloc] initWithFrame:CGRectMake(0, 0, 100, 20)];
[self.view addSubView:label];
self.userInteractionEnabled = YES;

向控件添加长按手势 

UITapGestureRecognizer *tgr = [[UITapGestureRecognizer alloc] initWithTarget:self action:@selector(labelClick)];
[label addGestureRecognizer: tgr];

 在长按响应事件中弹出菜单

// 让label成为第一响应者
[label becomeFirstResponder];
    
//获得菜单 - 单例模式
UIMenuController * menu = [UIMenuController sharedMenuController];
  
// 添加MenuItem
UIMenuItem* replay = [[UIMenuItem alloc] initWithTitle:@"回复" action:@selector(reply:)];
UIMenuItem* report = [[UIMenuItem alloc] initWithTitle:@"举报" action:@selector(report:)];
menu.menuItems = @[replay, report];

// 显示菜单
[menu setTargetRect:self.bounds inView:self];
[menu setMenuVisible:YES animated:YES];

重写方法控制菜单显示

- (BOOL)canBecomeFirstResponder{
    return YES;
}

- (BOOL)canPerformAction:(SEL)action withSender:(id)sender {
    if (action == @selector(reply:) || action ==  @selector(report:))
        return  YES;
    return NO;
}