在 C# 中使用 RestClient 作为 multipart/form-data 上传文件

Question

我正在尝试使用restClient (RestSharp) 请求从 c# 类上传文件。我正在创建 Method.POST 方法并将一个音频文件添加到此请求中作为 multipart/form-data。

当我执行请求时服务器抛出异常。

例外 ：

 System.ArgumentNullException: Value cannot be null.
 Parameter name: value
 at System.Enum.TryParseEnum(Type enumType, String value, Boolean ignoreCase, EnumResult& parseResult)
 at System.Enum.Parse(Type enumType, String value, Boolean ignoreCase)
 at Groove.Libraries.Helper.EnumHelper.ParseEnum[T](String value) in D:\project\Groove\Web\Groove\Libraries\Helper\EnumHelper.cs:line 47
 at Groove.Controllers.Api.DocumentController. 
 <PostDocumentUpload>d__5.MoveNext()

RestClient 请求代码：

string api_url = "http://localhost:57997/";
var fullFileName = "Adios.mp3";
var filepath = @"C:\Users\Admin\Desktop\Adios.mp3";

RestClient client = new RestClient(ApiModel.api_url);

var request = new RestRequest("api/document", Method.POST);
request.AddFile(Path.GetFileNameWithoutExtension(fullFileName), filepath);
request.AddHeader("Content-Type", "multipart/form-data");
request.AddParameter("ReferenceType",28,ParameterType.RequestBody);
IRestResponse response = client.Execute(request);

服务器代码：

public async Task<object> PostDocumentUpload()
    {
        try
        {
            // Make temp physical path where file to be saved
            var tempPath =
                HttpContext.Current.Server.MapPath(string.Format("{0}/{1}", Constants.MediaResourceFolder,
                    Constants.MediaResorceTempFolder));

            // Check temporary path is exist or not, if not then create temporary folder
            if (!Directory.Exists(tempPath))
            {
                Directory.CreateDirectory(tempPath);
            }

            // Create object of MyMultipartFormDataStreamProvider class
            var stream = new MultipartHelper(tempPath);

            // Save file at temp path
            await RequestContext.Request.Content.ReadAsMultipartAsync(stream);

            // Exception throw from Here,
            ReferenceType referenceType = EnumHelper.ParseEnum<ReferenceType>(stream.FormData["ReferenceType"]);
           // -------------other code     
        }
        catch (Exception ex)
        {
            return FailureResponse(ex);
        }

我想问题是 stream.FormData["ReferenceType"] 没有从请求中正确设置。

我不想更改服务器代码。因为当您从邮递员或浏览器调用时它工作正常。

有人可以帮忙吗？谢谢

Answer 1

我通过更改几个代码找到了解决方案。

更新代码：

       var request = new RestRequest("api/document", Method.POST);

        request.AddFile(Path.GetFileNameWithoutExtension(fullFileName), filepath);
        request.AddParameter("ReferenceType", ReferenceType.ToString());
        request.AddParameter("RefId", StudioEventEntryId.ToString());

        request.AlwaysMultipartFormData = true;

        IRestResponse response = client.Execute(request);