c# - Blazor - IHttpClientFactory.CreateClient 上的“指定转换无效”
问题描述
现在我正在尝试在 Blazor WASM 中实现绝对基本的（假）身份验证。我使用 .Net 5.0 和身份验证创建了一个 Visual Studio“Blazor Webassembly App”项目。我剥离了除 Index.razor 之外的 .razor 文件，它得到了以下实现
@page "/"
@inherits DataLayerGeneratorClient.Pages.Main.IndexBase
@using Microsoft.AspNetCore.Components.Authorization
@using Microsoft.AspNetCore.Components.WebAssembly.Authentication
<AuthorizeView>
<Authorized>
Hello, @context.User.Identity.Name!
<button class="nav-link btn btn-link" @onclick="Logout">
Log out
</button>
</Authorized>
<NotAuthorized>
<table>
<tr>
<td>User</td>
<td><input type="text" @bind="AuthenticationStateProvider.User" /></td>
</tr>
<tr>
<td>Password</td>
<td><input type="text" @bind="AuthenticationStateProvider.Password" /></td>
</tr>
</table>
<br />
<button @onclick="Login">Login</button>
</NotAuthorized>
</AuthorizeView>
和 IndexBase.cs
public class IndexBase : LayoutComponentBase
{
[Inject]
public IHttpClientFactory HttpClientFactory { get; set; }
[Inject]
public CustomAuthenticationStateProvider AuthenticationStateProvider { get; set; }
public async Task Login(MouseEventArgs e)
{
using (HttpClient client = HttpClientFactory.CreateClient("ServerAPI"))
{
...
}
}
}
我还做了一个 CustomAuthenticationStateProvider
public class CustomAuthenticationStateProvider : AuthenticationStateProvider
{
public override Task<AuthenticationState> GetAuthenticationStateAsync()
{
//Login failed
return Task.FromResult(new AuthenticationState(new ClaimsPrincipal(new ClaimsIdentity())));
//Login succeeded
//Claim claim = new Claim(ClaimTypes.Name, "TestUser");
//ClaimsIdentity claimsIdentity = new ClaimsIdentity(new[] { claim }, "fake auth");
//ClaimsPrincipal claimsPrincipal = new ClaimsPrincipal(claimsIdentity);
//AuthenticationState authenticationState = new AuthenticationState(claimsPrincipal);
//return Task.FromResult(authenticationState);
}
}
还有一个 CustomAuthorizationMessageHandler
public class CustomAuthorizationMessageHandler : AuthorizationMessageHandler
{
private readonly CustomAuthenticationStateProvider _customAuthenticationStateProvider;
public CustomAuthorizationMessageHandler(IAccessTokenProvider provider, NavigationManager navigation, CustomAuthenticationStateProvider customAuthenticationStateProvider) : base(provider, navigation)
{
if (customAuthenticationStateProvider == null)
{
throw new ArgumentNullException(nameof(customAuthenticationStateProvider));
}
_customAuthenticationStateProvider = customAuthenticationStateProvider;
}
...
}
在 App.razor 我更改了 DefaultLayout
DefaultLayout="@typeof(Index)"
最后是 Program.cs 的主要内容
public static async Task Main(string[] args)
{
var builder = WebAssemblyHostBuilder.CreateDefault(args);
builder.RootComponents.Add<App>("#app");
builder.Services.AddApiAuthorization();
builder.Services.AddAuthorizationCore();
builder.Services.AddScoped<CustomAuthenticationStateProvider>();
builder.Services.AddScoped<AuthenticationStateProvider, CustomAuthenticationStateProvider>();
builder.Services.AddScoped<CustomAuthorizationMessageHandler>();
builder.Services.AddScoped<AuthorizationMessageHandler, CustomAuthorizationMessageHandler>();
builder.Services.AddHttpClient("ServerAPI").AddHttpMessageHandler(sp =>
{
return sp.GetService<CustomAuthorizationMessageHandler>().ConfigureHandler(authorizedUrls: new[] { "http://localhost:10000" });
});
builder.Services.AddScoped(serviceProvider => serviceProvider.GetRequiredService<IHttpClientFactory>().CreateClient("ServerAPI"));
await builder.Build().RunAsync();
}
现在的问题。一旦 IHttpClientFactory.CreateHttpClient 被执行，它就会失败并显示错误“指定的强制转换无效”。什么演员表无效？
编辑 1 注入 HttpClient 而不是 IHttpClientFactory 似乎不是答案。当我测试它时，错误只是在启动而不是单击按钮时出现。如果有帮助，这里又是堆栈跟踪
System.InvalidCastException: Specified cast is not valid.
at Microsoft.Extensions.DependencyInjection.WebAssemblyAuthenticationServiceCollectionExtensions.<>c__0`3[[Microsoft.AspNetCore.Components.WebAssembly.Authentication.RemoteAuthenticationState, Microsoft.AspNetCore.Components.WebAssembly.Authentication, Version=5.0.2.0, Culture=neutral, PublicKeyToken=adb9793829ddae60],[Microsoft.AspNetCore.Components.WebAssembly.Authentication.RemoteUserAccount, Microsoft.AspNetCore.Components.WebAssembly.Authentication, Version=5.0.2.0, Culture=neutral, PublicKeyToken=adb9793829ddae60],[Microsoft.AspNetCore.Components.WebAssembly.Authentication.ApiAuthorizationProviderOptions, Microsoft.AspNetCore.Components.WebAssembly.Authentication, Version=5.0.2.0, Culture=neutral, PublicKeyToken=adb9793829ddae60]].<AddRemoteAuthentication>b__0_1(IServiceProvider sp)
at Microsoft.Extensions.DependencyInjection.ServiceLookup.CallSiteRuntimeResolver.VisitFactory(FactoryCallSite factoryCallSite, RuntimeResolverContext context)
at Microsoft.Extensions.DependencyInjection.ServiceLookup.CallSiteVisitor`2[[Microsoft.Extensions.DependencyInjection.ServiceLookup.RuntimeResolverContext, Microsoft.Extensions.DependencyInjection, Version=5.0.0.1, Culture=neutral, PublicKeyToken=adb9793829ddae60],[System.Object, System.Private.CoreLib, Version=5.0.0.0, Culture=neutral, PublicKeyToken=7cec85d7bea7798e]].VisitCallSiteMain(ServiceCallSite callSite, RuntimeResolverContext argument)
at Microsoft.Extensions.DependencyInjection.ServiceLookup.CallSiteRuntimeResolver.VisitCache(ServiceCallSite callSite, RuntimeResolverContext context, ServiceProviderEngineScope serviceProviderEngine, RuntimeResolverLock lockType)
at Microsoft.Extensions.DependencyInjection.ServiceLookup.CallSiteRuntimeResolver.VisitScopeCache(ServiceCallSite singletonCallSite, RuntimeResolverContext context)
at Microsoft.Extensions.DependencyInjection.ServiceLookup.CallSiteVisitor`2[[Microsoft.Extensions.DependencyInjection.ServiceLookup.RuntimeResolverContext, Microsoft.Extensions.DependencyInjection, Version=5.0.0.1, Culture=neutral, PublicKeyToken=adb9793829ddae60],[System.Object, System.Private.CoreLib, Version=5.0.0.0, Culture=neutral, PublicKeyToken=7cec85d7bea7798e]].VisitCallSite(ServiceCallSite callSite, RuntimeResolverContext argument)
at Microsoft.Extensions.DependencyInjection.ServiceLookup.CallSiteRuntimeResolver.VisitConstructor(ConstructorCallSite constructorCallSite, RuntimeResolverContext context)
at Microsoft.Extensions.DependencyInjection.ServiceLookup.CallSiteVisitor`2[[Microsoft.Extensions.DependencyInjection.ServiceLookup.RuntimeResolverContext, Microsoft.Extensions.DependencyInjection, Version=5.0.0.1, Culture=neutral, PublicKeyToken=adb9793829ddae60],[System.Object, System.Private.CoreLib, Version=5.0.0.0, Culture=neutral, PublicKeyToken=7cec85d7bea7798e]].VisitCallSiteMain(ServiceCallSite callSite, RuntimeResolverContext argument)
at Microsoft.Extensions.DependencyInjection.ServiceLookup.CallSiteRuntimeResolver.VisitCache(ServiceCallSite callSite, RuntimeResolverContext context, ServiceProviderEngineScope serviceProviderEngine, RuntimeResolverLock lockType)
at Microsoft.Extensions.DependencyInjection.ServiceLookup.CallSiteRuntimeResolver.VisitScopeCache(ServiceCallSite singletonCallSite, RuntimeResolverContext context)
at Microsoft.Extensions.DependencyInjection.ServiceLookup.CallSiteVisitor`2[[Microsoft.Extensions.DependencyInjection.ServiceLookup.RuntimeResolverContext, Microsoft.Extensions.DependencyInjection, Version=5.0.0.1, Culture=neutral, PublicKeyToken=adb9793829ddae60],[System.Object, System.Private.CoreLib, Version=5.0.0.0, Culture=neutral, PublicKeyToken=7cec85d7bea7798e]].VisitCallSite(ServiceCallSite callSite, RuntimeResolverContext argument)
at Microsoft.Extensions.DependencyInjection.ServiceLookup.CallSiteRuntimeResolver.Resolve(ServiceCallSite callSite, ServiceProviderEngineScope scope)
at Microsoft.Extensions.DependencyInjection.ServiceLookup.RuntimeServiceProviderEngine.<>c__DisplayClass1_0.<RealizeService>b__1(ServiceProviderEngineScope p)
at Microsoft.Extensions.DependencyInjection.ServiceLookup.RuntimeServiceProviderEngine.<>c__DisplayClass1_0.<RealizeService>b__0(ServiceProviderEngineScope scope)
at Microsoft.Extensions.DependencyInjection.ServiceLookup.ServiceProviderEngine.GetService(Type serviceType, ServiceProviderEngineScope serviceProviderEngineScope)
at Microsoft.Extensions.DependencyInjection.ServiceLookup.ServiceProviderEngineScope.GetService(Type serviceType)
at Microsoft.Extensions.DependencyInjection.ServiceProviderServiceExtensions.GetService[CustomAuthorizationMessageHandler](IServiceProvider provider)
at DataLayerGeneratorClient.Program.<>c.<Main>b__0_0(IServiceProvider sp) in D:\Dev\4.0\Test2\DataLayerGenerat…tem.Lazy`1[[Microsoft.Extensions.Http.ActiveHandlerTrackingEntry, Microsoft.Extensions.Http, Version=5.0.0.0, Culture=neutral, PublicKeyToken=adb9793829ddae60]].ExecutionAndPublication(LazyHelper executionAndPublication, Boolean useDefaultConstructor)
at System.Lazy`1[[Microsoft.Extensions.Http.ActiveHandlerTrackingEntry, Microsoft.Extensions.Http, Version=5.0.0.0, Culture=neutral, PublicKeyToken=adb9793829ddae60]].CreateValue()
at System.Lazy`1[[Microsoft.Extensions.Http.ActiveHandlerTrackingEntry, Microsoft.Extensions.Http, Version=5.0.0.0, Culture=neutral, PublicKeyToken=adb9793829ddae60]].get_Value()
at Microsoft.Extensions.Http.DefaultHttpClientFactory.CreateHandler(String name)
at Microsoft.Extensions.Http.DefaultHttpClientFactory.CreateClient(String name)
at DataLayerGeneratorClient.Program.<>c.<Main>b__0_1(IServiceProvider serviceProvider) in D:\Dev\4.0\Test2\DataLayerGeneratorClient\Program.cs:line 32
at Microsoft.Extensions.DependencyInjection.ServiceLookup.CallSiteRuntimeResolver.VisitFactory(FactoryCallSite factoryCallSite, RuntimeResolverContext context)
at Microsoft.Extensions.DependencyInjection.ServiceLookup.CallSiteVisitor`2[[Microsoft.Extensions.DependencyInjection.ServiceLookup.RuntimeResolverContext, Microsoft.Extensions.DependencyInjection, Version=5.0.0.1, Culture=neutral, PublicKeyToken=adb9793829ddae60],[System.Object, System.Private.CoreLib, Version=5.0.0.0, Culture=neutral, PublicKeyToken=7cec85d7bea7798e]].VisitCallSiteMain(ServiceCallSite callSite, RuntimeResolverContext argument)
at Microsoft.Extensions.DependencyInjection.ServiceLookup.CallSiteRuntimeResolver.VisitCache(ServiceCallSite callSite, RuntimeResolverContext context, ServiceProviderEngineScope serviceProviderEngine, RuntimeResolverLock lockType)
at Microsoft.Extensions.DependencyInjection.ServiceLookup.CallSiteRuntimeResolver.VisitScopeCache(ServiceCallSite singletonCallSite, RuntimeResolverContext context)
at Microsoft.Extensions.DependencyInjection.ServiceLookup.CallSiteVisitor`2[[Microsoft.Extensions.DependencyInjection.ServiceLookup.RuntimeResolverContext, Microsoft.Extensions.DependencyInjection, Version=5.0.0.1, Culture=neutral, PublicKeyToken=adb9793829ddae60],[System.Object, System.Private.CoreLib, Version=5.0.0.0, Culture=neutral, PublicKeyToken=7cec85d7bea7798e]].VisitCallSite(ServiceCallSite callSite, RuntimeResolverContext argument)
at Microsoft.Extensions.DependencyInjection.ServiceLookup.CallSiteRuntimeResolver.Resolve(ServiceCallSite callSite, ServiceProviderEngineScope scope)
at Microsoft.Extensions.DependencyInjection.ServiceLookup.RuntimeServiceProviderEngine.<>c__DisplayClass1_0.<RealizeService>b__1(ServiceProviderEngineScope p)
at Microsoft.Extensions.DependencyInjection.ServiceLookup.RuntimeServiceProviderEngine.<>c__DisplayClass1_0.<RealizeService>b__0(ServiceProviderEngineScope scope)
at Microsoft.Extensions.DependencyInjection.ServiceLookup.ServiceProviderEngine.GetService(Type serviceType, ServiceProviderEngineScope serviceProviderEngineScope)
at Microsoft.Extensions.DependencyInjection.ServiceLookup.ServiceProviderEngineScope.GetService(Type serviceType)
at Microsoft.AspNetCore.Components.ComponentFactory.<>c__DisplayClass6_0.<CreateInitializer>g__Initialize|2(IServiceProvider serviceProvider, IComponent component)
at Microsoft.AspNetCore.Components.ComponentFactory.PerformPropertyInjection(IServiceProvider serviceProvider, IComponent instance)
at Microsoft.AspNetCore.Components.ComponentFactory.InstantiateComponent(IServiceProvider serviceProvider, Type componentType)
at Microsoft.AspNetCore.Components.RenderTree.Renderer.InstantiateComponent(Type componentType)
at Microsoft.AspNetCore.Components.RenderTree.Renderer.InstantiateChildComponentOnFrame(RenderTreeFrame& frame, Int32 parentComponentId)
at Microsoft.AspNetCore.Components.RenderTree.RenderTreeDiffBuilder.InitializeNewComponentFrame(DiffContext& diffContext, Int32 frameIndex)
at Microsoft.AspNetCore.Components.RenderTree.RenderTreeDiffBuilder.InitializeNewSubtree(DiffContext& diffContext, Int32 frameIndex)
at Microsoft.AspNetCore.Components.RenderTree.RenderTreeDiffBuilder.InsertNewFrame(DiffContext& diffContext, Int32 newFrameIndex)
at Microsoft.AspNetCore.Components.RenderTree.RenderTreeDiffBuilder.AppendDiffEntriesForRange(DiffContext& diffContext, Int32 oldStartIndex, Int32 oldEndIndexExcl, Int32 newStartIndex, Int32 newEndIndexExcl)
at Microsoft.AspNetCore.Components.RenderTree.RenderTreeDiffBuilder.ComputeDiff(Renderer renderer, RenderBatchBuilder batchBuilder, Int32 componentId, ArrayRange`1 oldTree, ArrayRange`1 newTree)
at Microsoft.AspNetCore.Components.Rendering.ComponentState.RenderIntoBatch(RenderBatchBuilder batchBuilder, RenderFragment renderFragment)
at Microsoft.AspNetCore.Components.RenderTree.Renderer.RenderInExistingBatch(RenderQueueEntry renderQueueEntry)
at Microsoft.AspNetCore.Components.RenderTree.Renderer.ProcessRenderQueue()…
编辑 2 一旦我删除对 CustomAuthenticationStateProvider 的任何引用，错误就消失了。但这有什么意义呢？
编辑 3 我通过删除 AddApiAuthorization 并实现自定义 HttpMessageHandler 而不是 cucstom AuthorizationMessageHandler 使其工作
解决方案
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