问题描述
我在简单的ASP.NET Core 2.0 WebAPI应用程序中使用KeyFilter属性时遇到问题.
I have problem to using KeyFilter attribute in a simple ASP.NET Core 2.0 WebAPI application.
<PackageReference Include="Autofac" Version="4.6.1" />
<PackageReference Include="Autofac.Extensions.DependencyInjection" Version="4.2.0" />
<PackageReference Include="Microsoft.AspNetCore.All" Version="2.0.0" />
Program.cs:
Program.cs:
public class Program
{
public static void Main(string[] args)
{
BuildWebHost(args).Run();
}
public static IWebHost BuildWebHost(string[] args) =>
WebHost.CreateDefaultBuilder(args)
.ConfigureServices(services => services.AddAutofac())
.UseStartup<Startup>()
.Build();
}
Startup.cs:
Startup.cs:
public Startup(IConfiguration configuration)
{
Configuration = configuration;
}
public IConfiguration Configuration { get; }
public IContainer ApplicationContainer { get; private set; }
// This method gets called by the runtime.
// Use this method to add services to the container.
public IServiceProvider ConfigureServices(IServiceCollection services)
{
services.AddMvc();
// Autofac
var builder = new ContainerBuilder();
builder.Populate(services);
builder.RegisterType<ClassX1>()
.Keyed<IInterfaceX>("first")
.WithParameter("name", "X1")
.SingleInstance();
builder.RegisterType<ClassX1>()
.Keyed<IInterfaceX>("second")
.WithParameter("name", "X2")
.SingleInstance();
builder.RegisterType<ClassX1>()
.As<IInterfaceX>()
.WithParameter("name", "X3")
.SingleInstance();
builder.RegisterType<ValuesController>()
.WithAttributeFiltering();
ApplicationContainer = builder.Build();
return ApplicationContainer.Resolve<IServiceProvider>();
// return new AutofacServiceProvider(this.ApplicationContainer);
}
// This method gets called by the runtime.
// Use this method to configure the HTTP request pipeline.
public void Configure(IApplicationBuilder app, IHostingEnvironment env)
{
if (env.IsDevelopment())
{
app.UseDeveloperExceptionPage();
}
app.UseMvc();
}
ClassX1.cs:
ClassX1.cs:
public class ClassX1: IInterfaceX
{
public ClassX1(string name)
{
Name = name;
}
public string Name { get; }
}
IInterfaceX.cs:
IInterfaceX.cs:
public interface IInterfaceX
{
string Name { get; }
}
ValuesController.cs:
ValuesController.cs:
[Route("api/[controller]")]
public class ValuesController : Controller
{
private readonly IInterfaceX _x;
public ValuesController([KeyFilter("second")] IInterfaceX x)
{
_x = x;
}
// GET api/values
[HttpGet]
public IEnumerable<string> Get()
{
return new string[] { "value1", "value2", _x.Name };
}
}
调用"/api/values"会产生["value1","value2","X3"].但我希望["value1","value2","X2"].
Calling "/api/values" yield ["value1","value2","X3"].But i expect ["value1","value2","X2"].
如果我删除了第三个注册(使用X3),则
if i remove the third registration (with X3) then
尝试直接解析可以正确运行:
Trying to direct resolving works correct:
var temp = ApplicationContainer.ResolveKeyed<IInterfaceX>("second");
怎么了?
推荐答案
是的,它对于WebAPI控制器非常有效.
Yes, it works pretty cool for WebAPI Controllers.
解决方案是添加.AddControllersAsServices():
The solution is to add .AddControllersAsServices():
public IServiceProvider ConfigureServices(IServiceCollection services)
{
services.AddMvc().AddControllersAsServices();
这篇关于将KeyFilter与ASP.NET Core 2.0结合使用的文章就介绍到这了,希望我们推荐的答案对大家有所帮助,也希望大家多多支持!