我是DI库的新手,并尝试在Owin的WebApi 2项目中使用Autofac。这是我的Owin Startup课程,
[assembly: OwinStartup(typeof(FMIS.SIGMA.WebApi.Startup))]
namespace FMIS.SIGMA.WebApi
{
public class Startup
{
public void Configuration(IAppBuilder app)
{
var builder = new ContainerBuilder();
var config = new HttpConfiguration();
WebApiConfig.Register(config);
builder.RegisterApiControllers(Assembly.GetExecutingAssembly());
var container = builder.Build();
config.DependencyResolver = new AutofacWebApiDependencyResolver(container);
app.UseAutofacMiddleware(container);
app.UseAutofacWebApi(config);
app.UseWebApi(config);
ConfigureOAuth(app);
}
public void ConfigureOAuth(IAppBuilder app)
{
OAuthAuthorizationServerOptions OAuthServerOptions = new OAuthAuthorizationServerOptions()
{
AllowInsecureHttp = true,
TokenEndpointPath = new PathString("/token"),
AccessTokenExpireTimeSpan = TimeSpan.FromDays(1),
Provider = new SimpleAuthorizationServerProvider()
};
// Token Generation
app.UseOAuthAuthorizationServer(OAuthServerOptions);
app.UseOAuthBearerAuthentication(new OAuthBearerAuthenticationOptions());
}
}
}
当我调用Api方法时,我收到此错误
尝试创建类型的控制器时发生错误 'myController的'。确保控制器有一个 无参数公共构造函数。
我在这里缺少什么?
MyController 代码是这样的
public class MyController : ApiController
{
ISomeCommandHandler someCommanHandler;
public MyController(ISomeCommandHandler SomeCommandHandler)
{
this.someCommanHandler = SomeCommandHandler;
}
// POST: api/My
public void Post([FromBody]string value)
{
someCommanHandler.Execute(new MyCommand() {
Name = "some value"
});
}
// GET: api/My
public IEnumerable<string> Get()
{
}
// GET: api/My/5
public string Get(int id)
{
}
}
答案 0 :(得分:3)
您已将DependencyResolver
设置为AutofacWebApiDependencyResolver
,因此Autofac会发挥作用并为您实例化依赖项。现在,您必须明确告诉Autofac在需要接口实例时应该使用哪些具体实现。
您的控制器需要ISomeCommandHandler
的实例:
MyController(ISomeCommandHandler SomeCommandHandler)
因此,您需要配置公开该接口的类型:
builder.RegisterType<CommandHandler>.As<ISomeCommandHandler>();
有关Autofac注册概念的更多示例,请查看此documentation section。