禁止UITextField的弹出菜单 Select / Select All的出现

方法一1需要重写一个UITextField，比如：

#pragma mark -PasswordTextField
@implementation PasswordTextField

- (BOOL)canPerformAction:(SEL)action withSender:(id)sender
{
    if (action == @selector(paste:))
        return NO;
    if (action == @selector(select:))
        return NO;
    if (action == @selector(selectAll:))
        return NO;
    return [super canPerformAction:action withSender:sender];
}

@end

2方法二

-(BOOL)canPerformAction:(SEL)action withSender:(id)sender {
    UIMenuController *menuController = [UIMenuController sharedMenuController];
    if (menuController) {
        [UIMenuController sharedMenuController].menuVisible = NO;
    }
    return NO;
}