- (BOOL)textFieldShouldBeginEditing:(UITextField *)textField
{
    NSInteger tag = textField.tag;
    if(tag ==10 || tag ==11 || tag ==12){
        if(keyboardVisible){//判断键盘是否显示
            [textField resignFirstResponder];
        }
        [self moveTo:pickView andX:0 andY:HIGHT-230 andTime:0.3];
        return NO;
    }else{
        return YES;
    }


}

当键盘显示时，用[textField resignFirstResponder]为什么不能隐藏键盘？
执行了这句代码，但是键盘不能隐藏......

if(keyboardVisible){//判断键盘是否显示
            [textField resignFirstResponder];
}