如何解决此错误

首先，不要使用转换，使用 int.Parse （抛出异常）或者更好的是 int.TryParse 。并非所有人输入的字符串都可以解析为整数;我不知道为什么你决定 User.Identity.Name 应该。无论如何，使用我提到的方法，你可以检查它并处理无法解析字符串的情况。

-SA

First of all, don't use Convert, uses int.Parse (which throws exception) or, better, int.TryParse. Not all strings someone enters can be parsed as integer; I have no idea why did you decide that User.Identity.Name should. Anyway, with the methods I mentioned you can check it up and handle the cases when the string cannot be parsed.

—SA

除非 User.Identity.Name 始终只包含0到9的数字，并且具有适合Int32的总值， Convert.ToInt32 将永远失败。



鉴于它被称为名称它可能不是一个数字。我首先看看它应该包含什么，并检查你的实际含义是什么：

Unless User.Identity.Name always contains only the digits 0 to 9, and has a total value that will fit in an Int32, then Convert.ToInt32 will always fail.

Given that it's called Name the chances are that it isn't a number. I'd start by looking at what it should contain, and check if what you actually meant was something like:

changemodel.AdminId = Convert.ToInt32(User.Identity.Id);

或者更有可能：

Or more likely:

changemodel.AdminId = User.Identity.Id;

但是如果你必须转换它然后使用TryParse：

But if you do have to convert it then use TryParse:

if (!int.TryParse(User.Identity.Id, out changemodel.AdminId))
   {
   // Report or log problem
   ...
   }
else
   {
   // Work with value
   ...