.net - Swagger 错误 用于操作的模糊 HTTP 方法 操作需要显式 HttpMethod 绑定(bind)

Question

我正在尝试为我的 API 生成 swagger 文档。每次我导航到 Swagger 文档时，我都会收到此错误:

Ambiguous HTTP method for action - [ControllerName]Controller.DownloadFile. Actions require an explicit HttpMethod binding for Swagger/OpenAPI 3.0

这是它在我的 Controller 中提示的“违规”代码:

    using Models;
using Utilities;
using Microsoft.AspNetCore.Mvc;
using Microsoft.Extensions.Configuration;
using System;
using System.Collections.Generic;
using System.IO;
using System.Threading.Tasks;


namespace Controllers
{
    [Route("api/[controller]")]
    [ApiController]
    public class LibrarianController : ControllerBase
    {
        private IFileUploadUtilties fileUtilities;
        private IConfiguration config;
        private ApiContext context;
        private IFileRetrieval fileRetrieval;
        public LibrarianController(IFileUploadUtilties utilities, IConfiguration config, FinwiseApiContext context, IFileRetrieval fileRetrieval)
        {
            fileUtilities = utilities;
            this.config = config;
            this.context = context;
            this.fileRetrieval = fileRetrieval;
        }

       [HttpGet]
        public IActionResult Get()
        {
            return Ok("Ok");
        }

        // GET api/<LibrarianController>/5
        [HttpGet("/api/[controller]/{Id}")]
        public async Task<IActionResult> Get(int id)
        {
            try
            {
                return Ok(await fileRetrieval.GetFileForPartnerItemById(id));
            }
            catch(Exception ex)
            {
                return NotFound();
            }
            
        }
        [HttpGet ("/api/[controller]/[action]/{fileId}")]
        public async Task<IActionResult> DownloadFile(int fileId)
        {
            if (fileId == 0)
                return Content("File Id missing");

            var fileDownload = await fileRetrieval.GetFileForPartnerItemById(fileId);
            var contentType = await fileUtilities.GetFileType(Path.GetExtension(fileDownload.NewFileName));

            var path = Path.Combine(config.GetSection("StoredFilePath").Value, fileDownload.NewFileName);

            var memory = new MemoryStream();
            using (var stream = new FileStream(path, FileMode.Open))
            {
                await stream.CopyToAsync(memory);
            }
            memory.Position = 0;
            return File(memory, contentType, Path.GetFileName(path));
        }

        [HttpGet("api/[controller]/{PartnerId}/{ItemId}")]
        public async Task<List<FileUploads>> GetFiles(string PartnerId, string ItemId)
        {
            var getFiles =  await fileRetrieval.GetAllFilesForPartnerItem(PartnerId, ItemId);
            return getFiles;
        }
        
        
        // POST api/<LibrarianController>
        [HttpPost]
        public async Task<IActionResult> Post([FromForm] FileInformation fileInfo)
        {
            int newFileVersion = 1;

            if (fileInfo == null || fileInfo.Files == null || fileInfo.Files.Count == 0)
                return BadRequest("File(s) not found");

            try
            {
                foreach (var locFile in fileInfo.Files)
                {
                    //check for file extension, if not there, return an error
                    var fileExtension = Path.GetExtension(locFile.FileName);
                    if (string.IsNullOrEmpty(fileExtension))
                        return BadRequest("Files must include file extension");


                    var valid = await fileUtilities.IsFileValid(locFile);

                    var newFileName = string.Concat(Guid.NewGuid().ToString(),valid.fileExtension);

                    var newFileLocation = Path.Combine(config.GetSection("StoredFilePath").Value, newFileName);
                   

                    if (!valid.FileExtensionFound)
                    {
                        return BadRequest($"Error {valid.FileExtensionFoundError}");
                    }
                    if (!valid.FileSizeAllowed)
                    {
                        return BadRequest($"Error: {valid.FileSizeAllowedError}");
                    }


                    //check for an existing file in the database.  If there is one, increment the file version before the save
                    var currentFile = await fileUtilities.FileExists(fileInfo, locFile);

                    if (currentFile != null)
                    {
                        newFileVersion = currentFile.Version + 1;
                    }
              
                    //save to the file system
                    using (var stream = new FileStream(newFileLocation, FileMode.OpenOrCreate, FileAccess.ReadWrite))
                    {
                        await locFile.CopyToAsync(stream);
                    }

                    //save to the db.  Check to see if the file exists first.  If it does, do an insert, if not, return an error
                    if (System.IO.File.Exists(newFileLocation))
                    {
                        FileUploads upload = new FileUploads
                        {
                            EntityId = fileInfo.EntityId,
                            FileName = locFile.FileName,
                            ItemId = fileInfo.ItemId.ToString(),
                            NewFileName = newFileName,
                            ValidFile = true,
                            Version = newFileVersion
                        };
                        context.FileUploads.Add(upload);
                        context.SaveChanges();
                        //TODO: fire event the file has been saved provide Id key to find the record
                        //upload.Id;
                    }
                    else
                    {
                        return BadRequest("Error: File Could not be saved");
                    }

                }
            }
            catch (Exception ex)
            {
                return BadRequest("Failure to upload files.");
            }
            return Ok("File Uploaded");
        }

        // PUT api/<LibrarianController>/5
        [HttpPut("{id}")]
        public void Put(int id, [FromBody] string value)
        {
        }

        // DELETE api/<LibrarianController>/5
        [HttpDelete("{id}")]
        public void Delete(int id)
        {
        }
    }
}

当我测试它时，这个端点工作正常。我设置了路由，它用 HTTP 装饰，所以我不明白它在提示什么。我环顾四周寻找解决方案，但据我所知，它表明 Controller 中没有修饰的公共(public)方法，但是该 Controller 中没有未修饰的方法。这里有什么问题？如果我从 HttpGet 中删除路由信息，则无法访问该方法，因此我需要同时拥有 Route 和 HttpGet 装饰器才能访问此方法(除非我也做错了)。我怎样才能解决这个问题？

Answer 1

为什么模棱两可
这是您前往 DownloadFile() 的路线:

[HttpGet ("/api/[controller]/[action]/{fileId}")]
public async Task<IActionResult> DownloadFile(int fileId)

这是 GetFiles() :

[HttpGet("api/[controller]/{PartnerId}/{ItemId}")]
public async Task<List<FileUploads>> GetFiles(string PartnerId, string ItemId)

考虑一个 GET 请求 /api/Librarian/DownloadFile/62959061 .此网址适合两种操作:

对于 DownloadFile() , 下载文件为 [action]和 62959061 是 fileId .

对于 GetFiles() , 下载文件为 PartnerId和 62959061 是 ItemId . (在进行模型绑定(bind)时，.NET 会将 62959061 视为字符串。)

这就是为什么你有模棱两可的错误。
建议
为每个操作分配一个唯一的名称和可预测的路线。
1.方法名重复
而不是这些:

public IActionResult Get() { /*...*/ }
public async Task<IActionResult> Get(int id) { /*...*/ }

重命名方法之一以避免相同的方法名称:

public IActionResult Get() { /*...*/ }
public async Task<IActionResult> GetById(int id) { /*...*/ }

2. 定义独特的路线
形成你定义的 Controller ，我建议你使用 [RoutePrefix]在 Controller 级别并使用 [Route]或 [Http{Method}]在行动层面。 Here是关于它们是什么的相关讨论。
使用相同的模式定义路由可以避免意外创建模糊路由。以下是我重新定义路由的尝试:

[RoutePrefix("api/[controller]")] // api/Librarian
[ApiController]
public class LibrarianController : ControllerBase
{
    [HttpGet("")] // GET api/Librarian/
    public IActionResult Get() { /*...*/ }

    [HttpGet("{Id}")] // GET api/Librarian/62959061
    public async Task<IActionResult> GetById(int id) { /*...*/ }

    [HttpGet("download/{fileId}")] // GET api/Librarian/download/62959061
    public async Task<IActionResult> DownloadFile(int fileId) { /*...*/ }

    [HttpGet("getfiles/{PartnerId}/{ItemId}")] // GET api/Librarian/getfiles/partnerid/itemid
    public async Task<List<FileUploads>> GetFiles(string PartnerId, string ItemId) { /*...*/ }

    [HttpPost("")] // POST api/Librarian/
    public async Task<IActionResult> Post([FromForm] FileInformation fileInfo) { /*...*/ }

    [HttpPut("{id}")] // PUT api/Librarian/62959061
    public void Put(int id, [FromBody] string value) { /*...*/ }

    [HttpDelete("{id}")] // DELETE api/Librarian/62959061
    public void Delete(int id) { /*...*/ }
}

通过为 DownloadFile() 添加路径和 GetFiles()应用程序应该能够正确识别路线，因为应用程序知道 /download 的所有路线必去 DownloadFile()以及带有 /getfiles 的所有路线必去 GetFiles() .