c# - 内部不能有带有动态代码的 [Authorize()]

Question

我试图让授权接受角色作为枚举或 smart enum这样我就不必调试魔术字符串及其拼写错误

但我一直因为这两个错误而走入死胡同:

• Attribute constructor parameter 'roles' has type 'Role[]', which is not a valid attribute parameter type

• An attribute argument must be a constant expression, typeof expression or array creation expression of an attribute parameter type

这是我的代码:

AuthorizeRoles.cs

public class AuthorizeRoles : AuthorizeAttribute
{
    public AuthorizeRoles(params Role[] roles)
    {
        string allowed = string.Join(", ", roles.ToList().Select(x => x.Name));
        Roles = allowed;
    }
}

Role.cs

public class Role
{
    public readonly string Name;

    public enum MyEnum  // added
    {
        Admin,
        Manager
    }

    public static readonly Role Admin = new Role("Admin");
    public static readonly Role Manager = new Role("Manager");

    public Role(string name)
    {
        Name = name;
    }

    public override string ToString()
    {
        return Name;
    }

在我的 Controller 中我做了这个

    [AuthorizeRoles(Role.Admin, Role.Manager)]
    [AuthorizeRoles(Role.MyEnum.Admin)] // added 
    public IActionResult Index()
    {
        return Content("hello world");
    }

我看过这些答案，但没有用

• answer 1
• answer 2
• answer 3

Answer 1

由于 CLR 约束(属性如何存储在元数据中)，属性参数只能是原始类型或这些类型的数组(和 Type s)。你不能传递 Role (自定义对象)到属性。

枚举是有效的，但编译器无法将您的枚举 ( Role.MyEnum ) 转换为 Role ，这是 AuthorizeRoles 的构造函数的类型需要。所以这是一个编译器错误。

如您所料，解决方案是创建一个构造函数，该构造函数接受 Role.MyEnum 的数组。 ，如下所示:

public class AuthorizeRoles : Attribute
{
    public string Roles { get; private set; }

    public AuthorizeRoles(params Role.MyEnum[] roles)
    {
        string allowed = string.Join(", ", roles);
        Roles = allowed;
    }
}

public class Role
{
    public readonly string Name;

    public enum MyEnum
    {
        Admin,
        Manager
    }

    public Role(string name)
    {
        Name = name;
    }

    public override string ToString()
    {
        return Name;
    }
}

// ...

[AuthorizeRoles(Role.MyEnum.Admin)]
public IActionResult Index()
{
    // ...
}