自定义了一个Label，想在长按label时弹出自定义的操作菜单，用到了UIMenuController。
思路很简单，在label中添加长按手势，实现-(BOOL)canBecomeFirstResponder和- (BOOL)canPerformAction:(SEL)action withSender:(id)sender方法：
-(BOOL)canBecomeFirstResponder
{
return YES;
}
- (BOOL)canPerformAction:(SEL)action withSender:(id)sender
{
NSLog(@"%@",NSStringFromSelector(action));
if(action == @selector(cut:) || action == @selector(copy:) || action == @selector(myCut:)|| action == @selector(myPaste:)){
return YES;
}
else
{
return NO;
}
}
但是menu一直没有显示出来。
后来发现我在项目的其它地方设置了某个window makeKeyAndVisible，所以在-(BOOL)canBecomeFirstResponder中要额外做一些事情才能显示menu：
-(BOOL)canBecomeFirstResponder
{
UIWindow *window = [[UIApplication sharedApplication].delegate window];
if ([window isKeyWindow] == NO)
{
[window becomeKeyWindow];
[window makeKeyAndVisible];
}
return YES;
}
