C# 使用HttpClient上传文件并附带其他参数的步骤

using (HttpClient client = new HttpClient())
{
  var content = new MultipartFormDataContent();
  //添加字符串参数，参数名为qq
  content.Add(new StringContent("123456"), "qq");

  string path = Path.Combine(System.Environment.CurrentDirectory, "1.png");
  //添加文件参数，参数名为files，文件名为123.png
  content.Add(new ByteArrayContent(System.IO.File.ReadAllBytes(path)), "file", "123.png");

  var requestUri = "http://192.168.1.108:56852/api/Test/SaveFile";
  var result = client.PostAsync(requestUri, content).Result.Content.ReadAsStringAsync().Result;

  Console.WriteLine(result);
}

[HttpPost]
public async Task<JsonResult> SaveFile([FromForm]string qq, IFormFile file)
{
  return await Task.Run(() =>
  {
    try
    {
      //保存文件到本地
      var filefullPath = Path.Combine(Directory.GetCurrentDirectory(), file.FileName);
      using (FileStream fs = new FileStream(filefullPath, FileMode.Create))
      {
        file.CopyTo(fs);
        fs.Flush();
      }
    }
    catch (Exception ex)
    {
      return Fail(file.FileName + "---" + ex.Message);
    }
    return Success();
  });
}

public class SaveFileModel
{
  public string qq { get; set; }
  public IFormFile File { get; set; }
}
public async Task<JsonResult> SaveFile([FromForm]SaveFileModel model)
{
  //......
}

public async Task<JsonResult> SaveFile()
{
  return await Task.Run(() =>
  {
    var files = HttpContext.Request.Form.Files;
    var qq = HttpContext.Request.Form["qq"];
    //......
  });
}