如何在 UITextfield 中禁用 UIMenuController 的复制和定义 UIMenuItems

我正在实施自定义UIMenuController并试图弄清楚。如何合法禁用“复制”和“定义”UIMenuItemsUIMenuController in UITextfield？文本字段不可编辑。我尝试使用以下方法禁用“复制”：

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

    return [super canPerformAction:action withSender:sender];
}


- (IBAction)tapTextViewGesture:(id)sender {

  UIMenuItem *myItem1 = [[UIMenuItem alloc] initWithTitle:@"myItem1" action:@selector(myItem1Pressed:)];
  UIMenuItem *myItem2 = [[UIMenuItem alloc] initWithTitle:@"myItem2" action:@selector(myItem2Pressed:)];
  UIMenuItem *myItem3 = [[UIMenuItem alloc] initWithTitle:@"myItem3" action:@selector(myItem3Pressed:)];

    // Access the application's shared menu
    UIMenuController *menu = [UIMenuController sharedMenuController];

    [menu setMenuItems:[NSArray arrayWithObjects:myItem1,myItem2,myItem3, nil]];

    CGRect menuRect = CGRectMake(20, 50, 200, 0);


    // Show the menu from the cursor's position
    [menu setTargetRect:menuRect inView:self.view];


    [menu setMenuVisible:YES animated:YES];
}

但菜单仍然显示“复制”和“定义”UIMenuItems。我怎样才能禁用它们，只留下我的物品？

最后通过子类化解决了UITextView（为其创建自定义类）并刚刚添加

- (BOOL)canPerformAction:(SEL)action withSender:(id)sender
{

    if (action == @selector(copy:))
    {
        return NO;
    }

    return NO;
}

我的自定义 TextView 子类的 .m 文件内部。

之后“复制”不再出现，无论有没有[menu update];