ASP.NET Core 2-GetUserIdAsync返回带有Guid ID的空结果 [英] ASP.NET Core 2 - GetUserIdAsync returning null Result with Guid Ids

问题描述

我当前正在将网站移植到ASP.NET Core 2，并且当我使用扩展了 IdentityUser<的用户类调用 userManager.GenerateEmailConfirmationTokenAsync(user)时，引发了以下异常.Guid> :

I'm currently porting a site to ASP.NET Core 2 and am getting the following Exception thrown when I call userManager.GenerateEmailConfirmationTokenAsync(user) with a user class that extends IdentityUser<Guid>:

System.ArgumentNullException: Value cannot be null.
Parameter name: value
   at System.IO.BinaryWriter.Write(String value)
   at Microsoft.AspNetCore.Identity.DataProtectorTokenProvider`1.<GenerateAsync>d__11.MoveNext()

GenerateAsync() 调用 UserManager.GetUserIdAsync() ，它在 Result 中返回 null 值，而 Write()抱怨关于，即使我经过的 User 实例在 Id 中具有 07c0423e-f36b-1410-8007-800000000000 .

GenerateAsync() makes a call to UserManager.GetUserIdAsync(), which is returning the null value in Result, which Write() is complaining about, even though the User instance I'm passing through has 07c0423e-f36b-1410-8007-800000000000 in Id.

如果我直接在调用 GenerateEmailConfirmationTokenAsync()的同一个 UserManager 实例上直接调用 userManager.GetUserIdAsync(user)在 Result 中使用相同的 null 值.

If I call userManager.GetUserIdAsync(user) directly on the same UserManager instance on which I'm calling GenerateEmailConfirmationTokenAsync() I get this same null value in Result.

有人知道如何解决这个问题吗?

Does anyone have any ideas how to resolve this?

编辑:根据要求，可以在 github.com/上找到一个功能示例.BenjaminNolan/GetUserIdAsyncNullExample

Edit: As requested, a functional example can be found at github.com/BenjaminNolan/GetUserIdAsyncNullExample

推荐答案

您遇到的问题是

The problem you have is with these lines from your User class:

[Key]
[DatabaseGenerated(DatabaseGeneratedOption.Identity)]
[DefaultValue("NEWSEQUENTIALID()")]
new public Guid Id { get; set; }

您使用新修饰符此处禁止显示以下编译器警告:

Your use of the new modifier here is suppressing the following compiler warning:

'User.Id'隐藏继承的成员'IdentityUser.Id'.

'User.Id' hides inherited member 'IdentityUser.Id'.

此警告通知您，如果您通过 User 引用(而不是例如 IdentityUser< Guid> 引用-基础)访问 Id 类)，您将使用不同 Id 属性.如果在控制器中检查 user.Id 的值并将其与(((IdentityUser< Guid>)user).Id >(广播到基类以访问其 Id 属性).

This warning informs you that if you access Id via a User reference (rather than e.g. a IdentityUser<Guid> reference - the base class), you will be working with a different Id property. You can see what this looks like if you inspect the value of user.Id in your controller and compare that with the value of ((IdentityUser<Guid>)user).Id (casting to the base class in order to access its Id property).

很容易解决您的情况-只需从 User 类中删除 Id 属性:您已经指定了现有的 Id IdentityUser< TKey> 中的>属性将是 Guid 类型，并且其已配置为密钥，等等.

It's easy to fix in your case - just remove the Id property from your User class: you've already specified that the existing Id property from IdentityUser<TKey> will be of type Guid and its already configured to be the key, etc.

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