"Exception has been thrown by the target of an invocation" 在 ASP .Net Core 构造函数中注入 Amazon S3 服务时出错

Question

我有一个 ASP .Net Core 2.2 Web API。在其中，我有一个端点，前端（Angular 应用程序）可以将文件发送到 API，然后 API 又将此文件上传到 Amazon S3 存储桶（ us-east-1 地区）。

当我在 Visual Studio 中调试时，这非常有效，但是当我发布到我的服务器（Windows Server 2016）时，我得到以下异常：

Error: Exception has been thrown by the target of an invocation. at System.RuntimeMethodHandle.InvokeMethod(Object target, Object[] arguments, Signature sig, Boolean constructor, Boolean wrapExceptions) at System.Reflection.RuntimeConstructorInfo.Invoke(BindingFlags invokeAttr, Binder binder, Object[] parameters, CultureInfo culture)
at Amazon.Extensions.NETCore.Setup.ClientFactory.CreateClient(Type serviceInterfaceType, AWSCredentials credentials, ClientConfig config) at Amazon.Extensions.NETCore.Setup.ClientFactory.CreateServiceClient(ILogger logger, Type serviceInterfaceType, AWSOptions options) at Amazon.Extensions.NETCore.Setup.ClientFactory.CreateServiceClient(IServiceProvider provider) at Microsoft.Extensions.DependencyInjection.ServiceLookup.CallSiteRuntimeResolver.VisitFactory(FactoryCallSite factoryCallSite, ServiceProviderEngineScope scope) at Microsoft.Extensions.DependencyInjection.ServiceLookup.CallSiteVisitor2.VisitCallSite(IServiceCallSite callSite, TArgument argument) at Microsoft.Extensions.DependencyInjection.ServiceLookup.CallSiteRuntimeResolver.VisitScoped(ScopedCallSite scopedCallSite, ServiceProviderEngineScope scope) at Microsoft.Extensions.DependencyInjection.ServiceLookup.CallSiteRuntimeResolver.VisitSingleton(SingletonCallSite singletonCallSite, ServiceProviderEngineScope scope) at Microsoft.Extensions.DependencyInjection.ServiceLookup.CallSiteVisitor2.VisitCallSite(IServiceCallSite callSite, TArgument argument) at Microsoft.Extensions.DependencyInjection.ServiceLookup.CallSiteRuntimeResolver.VisitConstructor(ConstructorCallSite constructorCallSite, ServiceProviderEngineScope scope) at Microsoft.Extensions.DependencyInjection.ServiceLookup.CallSiteVisitor2.VisitCallSite(IServiceCallSite callSite, TArgument argument) at Microsoft.Extensions.DependencyInjection.ServiceLookup.CallSiteRuntimeResolver.VisitScoped(ScopedCallSite scopedCallSite, ServiceProviderEngineScope scope) at Microsoft.Extensions.DependencyInjection.ServiceLookup.CallSiteRuntimeResolver.VisitSingleton(SingletonCallSite singletonCallSite, ServiceProviderEngineScope scope) at Microsoft.Extensions.DependencyInjection.ServiceLookup.CallSiteVisitor2.VisitCallSite(IServiceCallSite callSite, TArgument argument) at Microsoft.Extensions.DependencyInjection.ServiceLookup.DynamicServiceProviderEngine.<>c__DisplayClass1_0. 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.ActivatorUtilities.GetService(IServiceProvider sp, Type type, Type requiredBy, Boolean isDefaultParameterRequired)
at lambda_method(Closure , IServiceProvider , Object[] ) at Microsoft.AspNetCore.Mvc.Controllers.ControllerActivatorProvider.<>c__DisplayClass4_0. b__0(ControllerContext controllerContext) at Microsoft.AspNetCore.Mvc.Controllers.ControllerFactoryProvider.<>c__DisplayClass5_0. g__CreateController|0(ControllerContext controllerContext) at Microsoft.AspNetCore.Mvc.Internal.ControllerActionInvoker.Next(State& next, Scope& scope, Object& state, Boolean& isCompleted) at Microsoft.AspNetCore.Mvc.Internal.ControllerActionInvoker.InvokeInnerFilterAsync() at Microsoft.AspNetCore.Mvc.Internal.ResourceInvoker.InvokeNextResourceFilter() at Microsoft.AspNetCore.Mvc.Internal.ResourceInvoker.Rethrow(ResourceExecutedContext context) at Microsoft.AspNetCore.Mvc.Internal.ResourceInvoker.Next(State& next, Scope& scope, Object& state, Boolean& isCompleted) at Microsoft.AspNetCore.Mvc.Internal.ResourceInvoker.InvokeFilterPipelineAsync() at Microsoft.AspNetCore.Mvc.Internal.ResourceInvoker.InvokeAsync()
at Microsoft.AspNetCore.Routing.EndpointMiddleware.Invoke(HttpContext httpContext) at Microsoft.AspNetCore.Routing.EndpointRoutingMiddleware.Invoke(HttpContext httpContext) at PropWorx.API.Middlewares.TenantIdentifier.Invoke(HttpContext httpContext, SharedContext sharedContext) in C:\Users\fabsr\source\repos\PropWorx.API\PropWorx.API\Middlewares\TenantIdentifier.cs:line 73 at Microsoft.AspNetCore.Builder.Extensions.MapWhenMiddleware.Invoke(HttpContext context) at Microsoft.AspNetCore.Builder.Extensions.MapWhenMiddleware.Invoke(HttpContext context) at Microsoft.AspNetCore.StaticFiles.StaticFileMiddleware.Invoke(HttpContext context) at Swashbuckle.AspNetCore.SwaggerUI.SwaggerUIMiddleware.Invoke(HttpContext httpContext) at Swashbuckle.AspNetCore.Swagger.SwaggerMiddleware.Invoke(HttpContext httpContext, ISwaggerProvider swaggerProvider) at Microsoft.AspNetCore.Authentication.AuthenticationMiddleware.Invoke(HttpContext context) at Microsoft.AspNetCore.Diagnostics.ExceptionHandlerMiddleware.Invoke(HttpContext context)

我在 %UserProfile%.aws 文件夹中创建了 "credentials" 文件。

我已将以下两个 NuGet 包添加到项目中：

AWSSDK.Extensions.NETCore.Setup
AWSSDK.S3

我的Startup.cs里有这个：

public void ConfigureServices(IServiceCollection services)
{
    services.AddAWSService<IAmazonS3>();
    services.AddSingleton<IS3Service, S3Service>();
}

S3Service.cs 看起来像这样：

public class S3Service : IS3Service
{
    private readonly IAmazonS3 _client;

    public S3Service(IAmazonS3 client)
    {
        _client = client;
    }

    // Some methods to upload and delete objects... not important
}

我将此服务注入我的控制器之一：

public class FilesController : ControllerBase
{
    private readonly IS3Service _s3Service;

    public FilesController(IS3Service s3Service)
    {
        _s3Service = s3Service;
    }

    // Some actions to receive the file... not important
}

只要我调用此控制器中的任何操作，就会发生错误。事实上，错误似乎是在将 S3Service 注入控制器的构造函数时发生的。如果我删除构造函数注入，即：

public class FilesController : ControllerBase
{
    private readonly IS3Service _s3Service;

    public FilesController()
    {
    }

    // Some actions to receive the file... not important
}

错误消失（当然不能正常工作）

有什么想法吗？就像我说的，这在我的笔记本电脑上完美运行，同时在 VS2017 中调试。但是当发布到服务器时它不起作用。 API 中的所有其他控制器工作正常。在构造函数中注入 S3Service 时似乎是个问题...

Answer 1

我更改了我的代码以不通过而是直接在我的 IS3Serice 方法中实例化它来获取 IAmazonS3 实例并且它起作用了。不知何故，DI 无法选择配置值，这就是无法解析对象的原因。

您可以从 here

获得一些相关信息

我仔细阅读了实际文档 https://docs.aws.amazon.com/sdk-for-net/v3/developer-guide/net-dg-config-netcore.html

并找到以下内容：

如果您查看项目属性中的“调试”选项卡，您会看到此文件设置为“开发”。这对于本地测试非常有用，因为您可以将配置放在 appsettings.Development.json 文件中，该文件在本地测试期间是只读的。当您部署 EnvironmentName 设置为 Production 的 Amazon EC2 实例时，该文件将被忽略，适用于 .NET 的 AWS 开发工具包回退到为 Amazon EC2 实例配置的 IAM 凭证和区域。

这可能是您在生产环境中尝试使用访问密钥时初始配置不起作用的原因。

也可以看看下面的回答

Answer 2

我保持简单。在我的本地机器上，我将密钥保存在用户机密中，而在生产服务器上，我将这些密钥保存在 IIS 配置文件中。并且只是从 ConfigurationManager 访问这些值。基本上它使用了新的 AmazonS3Client(string, string, string) 语法。此外，我使用的是一个非常旧的 .net 核心版本，这个问题有可能得到解决。查看似乎有效。

"Exception has been thrown by the target of an invocation" 在 ASP .Net Core 构造函数中注入 Amazon S3 服务时出错

"Exception has been thrown by the target of an invocation" error when injecting Amazon S3 Service in ASP .Net Core constructor

aws-sdk

asp.net-core

asp.net-core-webapi