ios-MBProgressHUD+MJ.h

showError: 会在[self.textfield resignFirstResponder];执行时隐藏不能达到显示2.5秒左右的效果

解决方法：
延时执行隐藏键盘的代码，延时正好等于showError:显示时长
[self performSelector:@selector(hideKeyBoardAfterShowCommentNote) withObject:self afterDelay:2.5];

- (void)hideKeyBoardAfterShowCommentNote
{
       [self.textfield resignFirstResponder];
}