即使路由存在，也没有找到该请求的候选人

Question

我有一个具有以下声明的控制器

[Authorize(Roles = Role.Admin)]
[ApiController]
[Route("meta/[controller]")]
public class ActionParameterController : BaseController<ActionParameterController>

里面有如下方法

[HttpPost("insert/{action}/{entity}")]
public IActionResult InsertActionParameter(
    [FromBody] MetaActionParameter parameter,
    int action,
    int entity)

但是，当我尝试向此端点发出 POST 请求时，我得到 404。 网址：

http://localhost:5000/meta/actionParameter/insert/2/2

控制台输出是：

2021-08-19 14:03:35.311 (Microsoft.AspNetCore.Hosting.Diagnostics.POST) [Information] Request starting HTTP/1.1 POST http://192.168.14.104:5000/meta/actionParameter/insert/1/2 - 0
2021-08-19 14:03:38.116 (Microsoft.AspNetCore.HostFiltering.HostFilteringMiddleware.) [Verbose] All hosts are allowed.
2021-08-19 14:03:38.117 (Microsoft.AspNetCore.StaticFiles.StaticFileMiddleware.POST) [Debug] "POST" requests are not supported
2021-08-19 14:03:38.120 (Microsoft.AspNetCore.StaticFiles.StaticFileMiddleware.POST) [Debug] "POST" requests are not supported
2021-08-19 14:03:38.125 (Microsoft.AspNetCore.StaticFiles.StaticFileMiddleware.POST) [Debug] "POST" requests are not supported
2021-08-19 14:03:38.132 (Microsoft.AspNetCore.Authentication.JwtBearer.JwtBearerHandler.) [Debug] AuthenticationScheme: "Bearer" was not authenticated.
2021-08-19 14:03:38.180 (Microsoft.AspNetCore.Routing.Matching.DfaMatcher.) [Debug] No candidates found for the request path '"/meta/actionParameter/insert/1/2"'
2021-08-19 14:03:38.182 (Microsoft.AspNetCore.Routing.EndpointRoutingMiddleware.) [Debug] Request did not match any endpoints
2021-08-19 14:03:38.185 (Microsoft.AspNetCore.Server.Kestrel.) [Debug] Connection id ""0HMB303OBKKOL"" completed keep alive response.
2021-08-19 14:03:38.191 (Microsoft.AspNetCore.Hosting.Diagnostics.POST) [Information] Request finished HTTP/1.1 POST http://192.168.14.104:5000/meta/actionParameter/insert/1/2 - 0 - 404 0 - 2880.056

我尝试从IActionDescriptorCollectionProvider 获取所有路线并打印路线。该控制器中还有其他可以工作的路由。

如果我将路由更改为仅“插入”，请求就会通过。据我所知，路线之间没有冲突。

我应该采取哪些进一步的步骤来诊断这个问题？

Answer 1

我想我知道问题出在哪里了。

我认为操作和/或插入字可能是保留字。

我使用以下代码进行了测试，并且成功了：

    [HttpGet("insert/{xaction}/{xentity}")]
    public IActionResult InsertActionParameterGet(int xaction, int xentity)
    {
        Console.WriteLine(xaction + " " + xentity);
    
        return new JsonResult("Ok");
}

请注意，我刚刚在动作和实体中添加了一个“x”，作为测试。
另外，我对 GET 操作进行了测试。
在添加“x”之前，它不起作用，所以我认为这些可能是保留字。

Answer 2

你需要在Http Method Attribute处写完整的router，像这样：

[HttpPost("meta/ActionParameter/insert/{action}/{entity}")]
public IActionResult InsertActionParameter([FromBody] MetaActionParameter parameter, int action, int entity)

Answer 3

这里有一个类似的问题：C# Web Api 2 PUT and POST requests "not supported"

根据那个，您似乎不应该使用 [FromBody]。
所以你的方法签名应该是这样的：

   [HttpPost("insert/{action}/{entity}")]
   public IActionResult InsertActionParameter(int action, int entity)

要准备好请求的正文，您可以执行以下操作：

            var bodyStr = "";
            var req = context.HttpContext.Request;
    
            // Allows using several time the stream in ASP.Net Core
            req.EnableRewind(); 
    
            // Arguments: Stream, Encoding, detect encoding, buffer size 
            // AND, the most important: keep stream opened
            using (StreamReader reader 
                      = new StreamReader(req.Body, Encoding.UTF8, true, 1024, true))
            {
                bodyStr = reader.ReadToEnd();
            }
    
            // Rewind, so the core is not lost when it looks the body for the request
            req.Body.Position = 0;
    
            // Do whatever work with bodyStr here