WebAPI 2.0发布和删除路由

Question

我在同一个控制器上有两个动作,具有相同的路径,但有不同的HttpMethod要求(POSTvs DELETE).

[AllowAnonymous]
public class TestController : ApiController
{
    [Route("~/api/test")]
    [HttpDelete]
    public IHttpActionResult Endpoint1()
    {
        return this.Ok("endpoint1");
    }

    [Route("~/api/test")]
    [HttpPost]
    public IHttpActionResult Endpoint2()
    {
        return this.Ok("endpoint2");
    }
}

这一切都很好 - 两个端点在切换时都DELETE有效POST.

例如

DELETE /api/test = endpoint1
POST /api/test = endpoint2

如果我将操作分成单独的控制器,它就不再起作用了:

[AllowAnonymous]
public class TestController : ApiController
{
    [Route("~/api/test")]
    [HttpDelete]
    public IHttpActionResult Endpoint1()
    {
        return this.Ok("endpoint1");
    }
}

[AllowAnonymous]
public class TestController2 : ApiController
{
    [Route("~/api/test")]
    [HttpPost]
    public IHttpActionResult Endpoint2()
    {
        return this.Ok("endpoint2");
    }
}

例如

DELETE /api/test = endpoint1
POST /api/test = { "Message": "The requested resource does not support http method 'POST'." }

这是从框架中预期的吗？

编辑: 确切的WebAPI包版本是:5.2.3

Answer 1

到底是怎么回事

Web API 2.0不允许在两个不同的控制器上匹配路由.这在MVC 6(Web API组合框架)中得到了解决.

我该怎么办呢

首先像@woogy,你说,它不是一个非常常见的模式,因此大多数用户不应该去这里(或者当它进入RTM时转移到MVC 6).

根本原因是路由实际匹配,动词定义了一个IActionHttpMethodProvider不限制路由匹配,并且它匹配多个控制器因此失败.

但是,您可以在路线上定义约束,并且作为副作用可以获得更简洁的API.

让我们开始吧

定义动词约束

这将限制路径仅匹配预定义的动词,因此它与其他控制器不匹配.

public class VerbConstraint : IHttpRouteConstraint
{
    private HttpMethod _method;

    public VerbConstraint(HttpMethod method)
    {
        _method = method;
    }

    public bool Match(HttpRequestMessage request,
                      IHttpRoute route,
                      string parameterName,
                      IDictionary<string, object> values,
                      HttpRouteDirection routeDirection)
    {
        // Note - we only want to constraint on the outgoing path
        if (routeDirection == HttpRouteDirection.UriGeneration || 
            request.Method == _method)        
        {
            return true;
        }

        return false;
    }
}

为新属性定义抽象基类

public abstract class VerbRouteAttribute : RouteFactoryAttribute, IActionHttpMethodProvider
{
    private string _template;
    private HttpMethod _method;

    public VerbRouteAttribute(string template, string verb)
        : base(template)
    {
        _method = new HttpMethod(verb);
    }

    public Collection<HttpMethod> HttpMethods
    {
        get
        {
            var methods = new Collection<HttpMethod>();
            methods.Add(_method);

            return methods;
        }
    }

    public override IDictionary<string, object> Constraints
    {
        get
        {
            var constraints = new HttpRouteValueDictionary();
            constraints.Add("verb", new VerbConstraint(_method));
            return constraints;
        }
    }
}

此类合并3件事1.路径属性与路径模板2.对路径应用动词路由约束3.指定动作方法选择器,因此系统的其余部分(如帮助页面)识别它就像[HttpPost]/[HttpDelete]

现在让我们定义实现

public class PostRouteAttribute : VerbRouteAttribute
{
    public PostRouteAttribute(string template) : base(template, "POST")
    {
    }
}

public class DeleteRouteAttribute : VerbRouteAttribute
{
    public DeleteRouteAttribute(string template) : base(template, "DELETE")
    {
    }
}

您可以告诉它们非常简单,只需在代码中使用这些属性就可以更加顺畅.

最后让我们应用新属性(并删除方法属性)

[AllowAnonymous]
public class TestController : ApiController
{
    [DeleteRoute("api/test")]
    public IHttpActionResult Endpoint1()
    {
        return this.Ok("endpoint1");
    }
}

[AllowAnonymous]
public class TestController2 : ApiController
{
    [PostRoute("api/test")]
    public IHttpActionResult Endpoint2()
    {
        return this.Ok("endpoint2");
    }
}