如何使用Web API上传文件和模型？

Basically I'm trying to upload an image along with an enum using Web API 2.

基本上我正在尝试使用Web API 2上传图像和枚举。

Here's the controller signature:

这是控制器签名：

[HttpPost]
public UploadResponseVm Upload([FromBody]ResImageType type)
{

The thing is, whenever I try to post a multipart form (with a file and a type) I get a 415 error:

问题是，每当我尝试发布多部分表单（带有文件和类型）时，我都会收到415错误：

{"Message":"The request entity's media type 'multipart/form-data' is not supported for this resource.","ExceptionMessage":"No MediaTypeFormatter is available to read an object of type 'ResImageType' from content with media type 'multipart/form-data'.","ExceptionType":"System.Net.Http.UnsupportedMediaTypeException","StackTrace":" at System.Net.Http.HttpContentExtensions.ReadAsAsync[T](HttpContent content, Type type, IEnumerable1 formatters, IFormatterLogger formatterLogger, CancellationToken cancellationToken)\r\n at System.Web.Http.ModelBinding.FormatterParameterBinding.ReadContentAsync(HttpRequestMessage request, Type type, IEnumerable1 formatters, IFormatterLogger formatterLogger, CancellationToken cancellationToken)"}

{“Message”：“此资源不支持请求实体的媒体类型'multipart / form-data'。”，“ExceptionMessage”：“没有MediaTypeFormatter可用于从具有媒体类型的内容中读取'ResImageType'类型的对象'multipart / form-data'。“，”ExceptionType“：”System.Net.Http.UnsupportedMediaTypeException“，”StackTrace“：”at System.Net.Http.HttpContentExtensions.ReadAsAsync [T]（HttpContent内容，类型类型，IEnumerable1 formatters，IFormatterLogger formatterLogger，CancellationToken cancellationToken）\ r \ n在System.Web.Http.ModelBinding.FormatterParameterBinding.ReadContentAsync（HttpRequestMessage请求，类型类型，IEnumerable1格式化程序，IFormatterLogger formatterLogger，CancellationToken cancellationToken）“}

I have even added the following to my startup.cs class:

我甚至在startup.cs类中添加了以下内容：

    config.Formatters.Insert(0, new System.Net.Http.Formatting.JsonMediaTypeFormatter());

How can I upload a model along with a file using a web api controller?

如何使用web api控制器上传模型和文件？

1 个解决方案

#1

There is no formatter that could handle/relate to your ResImageType object. I have once solved a similar problem without a formatter by using a parameter-less method and have processed the data inside the method. For example:

没有可以处理/与您的ResImageType对象相关的格式化程序。我曾经使用无参数方法解决了没有格式化程序的类似问题，并处理了方法中的数据。例如：

public async Task<HttpResponseMessage> PostFormData()
    {
        if (!Request.Content.IsMimeMultipartContent("form-data"))
        {
            return Request.CreateResponse(HttpStatusCode.BadRequest);
        }

            string upDir= "PathOfDirectory";

            MultipartFormDataStreamProvider streamProvider = new MultipartFormDataStreamProvider(upDir);                
            MultipartFileStreamProvider multipartFileStreamProvider = await Request.Content.ReadAsMultipartAsync(streamProvider);

            // Loop through files.
            foreach (MultipartFileData file in streamProvider.FileData)
            {
                // Save filepaths to DB or do something else
            }
            return Request.CreateResponse(HttpStatusCode.OK);
    }

Similar solution from MS Docs

来自MS Docs的类似解决方案

Another possibility is to create a DTO-like class that is used to transfer the object and use a formatter, for example MultipartDataMediaFormatter seems legit (haven't tried).

另一种可能性是创建一个类似DTO的类，用于传输对象并使用格式化程序，例如MultipartDataMediaFormatter似乎合法（尚未尝试过）。