如何在 AuthenitcationStateProvider (.Net 6) 中使用 Blazored.LocalStorage？

Question

我正在尝试在我的 CustomAuthStateProvider class 中使用 localStorageService，这样我就可以基于 LocalStorage 中的密钥创建一个 AuthenticationState（只是为了学习和练习）。 然而，当我运行我的应用程序时，我收到一条错误消息，告诉我找不到适合 CustomAuthStateProvider 的构造函数。 该错误是有道理的，但我不明白如何修复它并且在网上找不到太多。

这是错误：

Microsoft.AspNetCore.Components.WebAssembly.Rendering.WebAssemblyRenderer[100]
      Unhandled exception rendering component: A suitable constructor for type 'BlazorBattles.Client.CustomAuthStateProvider' could not be located. Ensure the type is concrete and services are registered for all parameters of a public constructor.
System.InvalidOperationException: A suitable constructor for type 'BlazorBattles.Client.CustomAuthStateProvider' could not be located. Ensure the type is concrete and services are registered for all parameters of a public constructor.

这是我的 CustomAuthStateProvider implimenting AuthenticationStateProvider：

public class CustomAuthStateProvider : AuthenticationStateProvider
    {
        private readonly ILocalStorageService _localStorageService;
        CustomAuthStateProvider(ILocalStorageService localStorageService)
        {
            _localStorageService = localStorageService;
        }

        public override async Task<AuthenticationState> GetAuthenticationStateAsync()
        {
            if (await _localStorageService.GetItemAsync<bool>("isAuthenticated"))
            {
                ClaimsIdentity claimsIdentity = new ClaimsIdentity(new[]
                {
                    new Claim(ClaimTypes.Name, "Thomas")
                }, "Test Authentication");

                ClaimsPrincipal user = new ClaimsPrincipal(claimsIdentity);
                AuthenticationState state = new AuthenticationState(user);

                //Tell all the components that the Auth state has changed
                NotifyAuthenticationStateChanged(Task.FromResult(state));
                return (state);
            }

            //This will result in an unauthorised user because it does not have a claims identity
            return (new AuthenticationState(new ClaimsPrincipal()));
        }
    }

这是我的 Program.cs

using BlazorBattles.Client;
using BlazorBattles.Client.Services;
using Microsoft.AspNetCore.Components.Web;
using Microsoft.AspNetCore.Components.WebAssembly.Hosting;
using Blazored.Toast;
using Blazored.LocalStorage;
using Microsoft.AspNetCore.Components.Authorization;

var builder = WebAssemblyHostBuilder.CreateDefault(args);
builder.RootComponents.Add<App>("#app");
builder.RootComponents.Add<HeadOutlet>("head::after");

builder.Services.AddBlazoredToast();
builder.Services.AddBlazoredLocalStorage();
builder.Services.AddScoped(sp => new HttpClient { BaseAddress = new Uri(builder.HostEnvironment.BaseAddress) });
builder.Services.AddScoped<IBananaService, BananaService>();
builder.Services.AddScoped<IUnitService, UnitService>();
builder.Services.AddScoped<AuthenticationStateProvider, CustomAuthStateProvider>();
builder.Services.AddOptions();
builder.Services.AddAuthorizationCore();

await builder.Build().RunAsync();

我为 Blazored.LocalStorage 使用 V4.3.0，为 Microsoft.AspNetCore.Components.Authorization 使用 V6

谢谢。

当我删除构造函数和对 LocalStorage 的引用时，它按预期工作，但是当我尝试注入 LocalStorage 以使用它时，我得到了错误。 我不确定在这种特定情况下如何正确使用构造函数？

更新：我的问题的解决方案是为构造函数添加 public 关键字

Answer 1

我认为您的主要问题是您的自定义AuthenticationStateProvider inheritance。

这是我的“传递”WASM 提供程序，它注入（但从不使用）本地存储。 它只是从基本代码中获取用户。 请注意它是 inheritance。

    public class CustomAuthenticationStateProvider 
        : RemoteAuthenticationService<RemoteAuthenticationState, RemoteUserAccount, MsalProviderOptions>
    {
        private readonly ILocalStorageService _localStorageService;

        public CustomAuthenticationStateProvider(
            IJSRuntime jsRuntime, 
            IOptionsSnapshot<RemoteAuthenticationOptions<MsalProviderOptions>> options, 
            NavigationManager navigation, 
            AccountClaimsPrincipalFactory<RemoteUserAccount> accountClaimsPrincipalFactory,
            ILocalStorageService localStorageService
            ) 
            : base(jsRuntime, options, navigation, accountClaimsPrincipalFactory)
        {
            _localStorageService= localStorageService;
        }

        public async override Task<AuthenticationState> GetAuthenticationStateAsync()
        {
            var auth = await base.GetAuthenticationStateAsync();

            return new AuthenticationState(auth.User ?? new ClaimsPrincipal());
        }
    }

作为参考，这里是我使用 AzureAD 进行身份验证的程序。

var builder = WebAssemblyHostBuilder.CreateDefault(args);
builder.RootComponents.Add<App>("#app");
builder.RootComponents.Add<HeadOutlet>("head::after");

builder.Services.AddHttpClient("Blazr.AzureOIDC.WASM.ServerAPI", client => client.BaseAddress = new Uri(builder.HostEnvironment.BaseAddress))
    .AddHttpMessageHandler<BaseAddressAuthorizationMessageHandler>();

// Supply HttpClient instances that include access tokens when making requests to the server project
builder.Services.AddScoped(sp => sp.GetRequiredService<IHttpClientFactory>().CreateClient("Blazr.AzureOIDC.WASM.ServerAPI"));

builder.Services.AddMsalAuthentication(options =>
{
    builder.Configuration.Bind("AzureAd", options.ProviderOptions.Authentication);
    options.ProviderOptions.DefaultAccessTokenScopes.Add("api://api.id.uri/access_as_user");
});
builder.Services.AddBlazoredLocalStorage();
builder.Services.AddScoped<AuthenticationStateProvider, CustomAuthenticationStateProvider>();

await builder.Build().RunAsync();

Answer 2

尝试像这样注册CustomAuthStateProvider服务：

// Make the same instance accessible as both AuthenticationStateProvider and CustomAuthStateProvider
builder.Services.AddScoped<CustomAuthStateProvider>();
builder.Services.AddScoped<AuthenticationStateProvider>(provider => provider.GetRequiredService<CustomAuthStateProvider>());

Answer 3

我上面的代码的问题是我在构造函数中遗漏了 public 关键字，现在它按预期工作了。 非常感谢所有对我的帖子发表评论并提供潜在解决方案的人，感谢您花时间帮助我！

原始代码：

CustomAuthStateProvider(ILocalStorageService localStorageService)
{
    _localStorageService = localStorageService;
}

更新代码：

public CustomAuthStateProvider(ILocalStorageService localStorageService)
{
    _localStorageService = localStorageService;
}