C# web api post 图像作为表单数据

Question

在 postman 中很容易做到：

为了通过网络实现它api，我写了下面的代码：

HttpClient client = new HttpClient();
string url = "https://upload.*******.com/api/upload/photos";
client.BaseAddress = new Uri(url);
client.DefaultRequestHeaders.Clear();

client.DefaultRequestHeaders.Accept.Add(new MediaTypeWithQualityHeaderValue("multipart/form-data"));

byte[] data;
using (var br = new BinaryReader(inputPhotoUpload.files.OpenReadStream()))
data = br.ReadBytes((int) inputPhotoUpload.files.OpenReadStream().Length);

ByteArrayContent bytes = new ByteArrayContent(data);

MultipartFormDataContent multipartFormDataContent = new 
MultipartFormDataContent();
multipartFormDataContent.Add(new StringContent(inputPhotoUpload.watermark.ToString()), "watermark");
multipartFormDataContent.Add(new StringContent("listing"), "type");
multipartFormDataContent.Add(bytes, "files", inputPhotoUpload.files.FileName);

HttpResponseMessage res = await client.PostAsync(url, multipartFormDataContent);

我的 InputPhotoUpload class

public class InputPhotoUpload
{
    public string watermark { get; set; }
    public string type { get; set; }
    public IFormFile files { get; set; }
}

上传服务器接受字节数组中的图像和另外两个名为 listing 和 watermark 的值。服务器给出代码 500 内部错误。 我的目标是 post 表单数据 post 上传图片，post 人可以做到但我的控制器 api 不能。

Answer 1

显然我需要将所有 headers 与邮递员同步，有些是不必要的。

 HttpClient client = new HttpClient();
                MultipartFormDataContent form = new MultipartFormDataContent();
                client.DefaultRequestHeaders.Clear();         

                ByteArrayContent bytes = new ByteArrayContent(imageStream);
                form.Add(bytes, "files", imageName);
                form.Add(new StringContent("En"), "watermark");
                form.Add(new StringContent("listing"), "type");


                HttpResponseMessage response = await client.PostAsync("https://upload.*****.com/api/upload/photos", form);
                var k = response.Content.ReadAsStringAsync().Result;

                _Result = JsonConvert.DeserializeObject<List<Output>>(k);