System.AggregateException:“Some services are not able to be constructed, Unable to resolve service for type 'Microsoft.AspNetCore.Http.IHttpContextAccessor

System.AggregateException:“Some services are not able to be constructed (Error while validating the service descriptor 'ServiceType: CSFramework.LicenseCoreWebApi.UserContext Lifetime: Scoped ImplementationType: CSFramework.LicenseCoreWebApi.UserContext': Unable to resolve service for type 'Microsoft.AspNetCore.Http.IHttpContextAccessor' while attempting to activate 'CSFramework.LicenseCoreWebApi.UserContext'.) (Error while validating the service descriptor 'ServiceType: CSFramework.LicenseCore.Interfaces.IUserContext Lifetime: Scoped ImplementationType: CSFramework.LicenseCoreWebApi.UserContext': Unable to resolve service for type 'Microsoft.AspNetCore.Http.IHttpContextAccessor' while attempting to activate 'CSFramework.LicenseCoreWebApi.UserContext'.) (Error while validating the service descriptor 'ServiceType: CSFramework.LicenseServerV3.Business.LicenseAdminToolBusiness Lifetime: Scoped ImplementationType: CSFramework.LicenseServerV3.Business.LicenseAdminToolBusiness': Unable to resolve service for type 'Microsoft.AspNetCore.Http.IHttpContextAccessor' while attempting to activate 'CSFramework.LicenseCoreWebApi.UserContext'.) (Error while validating the service descriptor 'ServiceType: CSFramework.LicenseCore.Interfaces.IDataServiceAdmin Lifetime: Scoped ImplementationType: CSFramework.LicenseServerV3.Business.LicenseAdminToolBusiness': Unable to resolve service for type 'Microsoft.AspNetCore.Http.IHttpContextAccessor' while attempting to activate 'CSFramework.LicenseCoreWebApi.UserContext'.)”

错误原因

无法解析Microsoft.AspNetCore.Http.IHttpContextAccessor接口服务类型。

Microsoft.AspNetCore.Http.IHttpContextAccessor接口不能作为自动注入接口的参数使用，如：

public UserContext(IServiceProvider serviceProvider, IHttpContextAccessor httpContext)
{
    _serviceProvider = serviceProvider;
    this.IP = httpContext.HttpContext.GetClientIP();
}

解决方案

注入 HttpContextAccessor ：

builder.Services.AddHttpContextAccessor();

注入后，建议改用下面代码：

取消 Microsoft.AspNetCore.Http.IHttpContextAccessor 接口作为注入接口的参数，改为获取服务方式：

public UserContext(IServiceProvider serviceProvider)
{
    _serviceProvider = serviceProvider;

    var provider = serviceProvider.GetService<IHttpContextAccessor>();
    if (provider != null)
    {
        this.IP = provider.HttpContext.GetClientIP();
    }
}