IOS MenuController初步了解

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• 默认情况下有以下控件已经支持MenuController。
  • UITextField
  • UITextView
  • UIWebView

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• 让其他控件也支持MenuController

    例如:UILabel
  

• 自定义label

• 重写两个方法

 //允许自己成为第一响应者
- (BOOL)canBecomeFirstResponder{
    return YES;
}
//Label能够执行哪些操作（menu）
- (BOOL)canPerformAction:(SEL)action withSender:(id)sender{

    if (action == @selector(copy:) || action == @selector(cut:)) {
        return YES;
    }

    return NO;
}

• 实现各种操作方法

 - (void)copy:(id)sender{
    //复制版
    UIPasteboard * paste = [UIPasteboard generalPasteboard];

    paste.string = self.text;

}

- (void)cut:(id)sender{

    UIPasteboard * paste = [UIPasteboard generalPasteboard];

    paste.string = self.text;

    self.text = nil;

}

- (void)paste:(id)sender{

    UIPasteboard * paste = [UIPasteboard generalPasteboard];

    self.text = paste.string;

}

• 让Label成为第一响应者

 //让自己成为第一响应者
    [self becomeFirstResponder];

• 显示MenuController

     //初始化menu
    UIMenuController * menu = [UIMenuController sharedMenuController];
    //设置menu的显示位置
    [menu setTargetRect:self.frame inView:self.superview];
    //让menu显示并且伴有动画
    [menu setMenuVisible:YES animated:YES];