ASP.NET Core RoleManager在Blazor Server中创建新角色失败

我正在开发Blazor Server应用，实现角色创建功能时遇到问题：调用RoleManager.CreateAsync(newRole)时，即使传入硬编码的角色名（比如"Administrator"），仍会抛出角色名无效的错误，日志提示：

Microsoft.AspNetCore.Identity.RoleManager[0]
      Role (null) validation failed: InvalidRoleName.
fail: TestWebsite.Pages.Admin.Users[0]
      Role name '' is invalid.
fail: TestWebsite.Pages.Admin.Users[0]
      InvalidRoleName

已确认传入的ApplicationRole对象名称不为空，且ApplicationRole仅继承IdentityRole未做重写，猜测问题出在依赖注入或Identity服务实现上。

相关代码 #

Blazor页面注入与创建逻辑 #

@inject RoleManager<ApplicationRole> roleManager

@code {
    // 省略其他页面逻辑代码...

    // ===== NEW ROLE CREATION =====
    private bool _creatingRole = false;
    private RoleModel roleModel = new();
    private EditContext? editContext;

    protected override void OnInitialized() {
        editContext = new(roleModel);
        editContext.EnableDataAnnotationsValidation();
    }

    private async Task HandleValidSubmit() {
        if (editContext != null && editContext.Validate()) {
            Logger.LogInformation(roleModel.Name);
            ArgumentNullException.ThrowIfNull(roleModel.Name);

            // 硬编码角色名仍报错
            var result = await roleManager.CreateAsync(new ApplicationRole("Administrator"));

            if (result.Succeeded)
            {
                _creatingRole = false;
                _loadingRoles = true;
                LoadAllRoles();
            } 
            else
            {
                foreach (var error in result.Errors)
                {
                    Logger.LogError(error.Description);
                    Logger.LogError(error.Code);
                }
            }
        }
    }

    public class RoleModel
    {
        [Required(ErrorMessage = "Role name is required")]
        [StringLength(256, MinimumLength = 3, ErrorMessage = "Role name must be 3 to 256 characters long")]
        public string? Name { get; set; }
    }
}

Program.cs配置 #

using TestWebsite.Data.Identity;
using TestWebsite.Models;
using Microsoft.AspNetCore.Identity;
using System.Data;
using System.Data.SqlClient;

var builder = WebApplication.CreateBuilder(args);

builder.Services.AddRazorPages();
builder.Services.AddServerSideBlazor();

builder.Services.AddScoped<IDapperUserStore, DapperUserStore>();
builder.Services.AddScoped<IDapperRoleStore, DapperRoleStore>();

builder.Services
    .AddIdentity<ApplicationUser, ApplicationRole>()
    .AddUserStore<DapperUserStore>()
    .AddRoleStore<DapperRoleStore>()
    .AddDefaultTokenProviders();

builder.Services.AddTransient<IDbConnection>(
    sp => new SqlConnection(builder.Configuration.GetConnectionString("KristeraLocal"))
);

var app = builder.Build();

// 省略中间件配置...
app.Run();

问题根源与解决方法 #

问题出在你自定义的DapperRoleStore实现上。RoleManager.CreateAsync执行时，会先通过IRoleStore<TRole>的GetRoleNameAsync方法获取角色名称，再进行验证。如果你的DapperRoleStore中GetRoleNameAsync方法没有正确返回角色的Name属性，就会导致验证时认为角色名为空。

检查并修正DapperRoleStore的以下核心方法：

• GetRoleNameAsync：确保正确返回角色对象的Name属性

  public Task<string> GetRoleNameAsync(ApplicationRole role, CancellationToken cancellationToken = default)
  {
      cancellationToken.ThrowIfCancellationRequested();
      return Task.FromResult(role.Name);
  }
  

• SetRoleNameAsync：确保正确为角色对象赋值名称

  public Task SetRoleNameAsync(ApplicationRole role, string roleName, CancellationToken cancellationToken = default)
  {
      cancellationToken.ThrowIfCancellationRequested();
      role.Name = roleName;
      return Task.CompletedTask;
  }
  

• 规范化名称处理：确保GetNormalizedRoleNameAsync和SetNormalizedRoleNameAsync正确处理规范化名称（通常转大写），避免后续其他验证或存储问题

  public Task<string> GetNormalizedRoleNameAsync(ApplicationRole role, CancellationToken cancellationToken = default)
  {
      cancellationToken.ThrowIfCancellationRequested();
      return Task.FromResult(role.NormalizedName);
  }
  
  public Task SetNormalizedRoleNameAsync(ApplicationRole role, string normalizedName, CancellationToken cancellationToken = default)
  {
      cancellationToken.ThrowIfCancellationRequested();
      role.NormalizedName = normalizedName;
      return Task.CompletedTask;
  }
  

同时确认DapperRoleStore的CreateAsync方法中，正确将角色的Name和NormalizedName写入数据库，规范化名称建议通过RoleManager的NormalizeKey方法生成（或手动转大写）。

内容的提问来源于stack exchange，提问作者Kristers