C#使用HttpClient上传文件并附带其他参数

HttpClient和MultipartFormDataContent（传送门）最低适用于.NET Framework 4.5版本

发送端代码

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);
}

接收端代码

[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();
    });
}