C# HttpClient Post 参数同时上传文件上传图片调用接口

// 调用接口上传文件
using (var client = new HttpClient())
{
    using (var multipartFormDataContent = new MultipartFormDataContent())
    {
        var values = new[]
        {
            new KeyValuePair<string, string>("a", "3"),
            new KeyValuePair<string, string>("c", "2"),
            new KeyValuePair<string, string>("d", "2")
             //other values
        };
  
        foreach (var keyValuePair in values)
        {
            multipartFormDataContent.Add(new StringContent(keyValuePair.Value),
                String.Format("\"{0}\"", keyValuePair.Key));
        }
  
        multipartFormDataContent.Add(new ByteArrayContent(System.IO.File.ReadAllBytes(@"D:\test.jpg")),
            "\"pic\"",
            "\"test.jpg\"");
  
        var requestUri = "http://localhost:8080";
        var html = client.PostAsync(requestUri, multipartFormDataContent).Result.Content.ReadAsStringAsync().Result;
    }
}

API 接口，接收请求参数和上传的文件

public string UploadHeadImg()
     {
 
         var ts = HttpContext.Current.Request["d"];
         HttpPostedFile file = System.Web.HttpContext.Current.Request.Files[0];
         // 文件扩展名
         string fileExtension = Path.GetExtension(file.FileName).ToLower();    
  
         Stream sr = file.InputStream;//头像文件流
         Bitmap bitmap = (Bitmap)Bitmap.FromStream(sr);
         bitmap.Save(“c:/img/1.jpg”, System.Drawing.Imaging.ImageFormat.Jpeg);
       return "success";
     }