如何在C#中使用HttpClient发送文件和表单数据

Question

如何使用HttpClient？发送文件和表单数据？

我有两种方法来发送文件或表单数据.但我想像HTML表单一样发送它们.我怎样才能做到这一点？谢谢.

这是我的代码:

if (openFileDialog1.ShowDialog() == DialogResult.OK)
{
    var client = new HttpClient();
    var requestContent = new MultipartFormDataContent();
    filename = openFileDialog1.FileName;
    array = File.ReadAllBytes(filename);
    var imageContent = new ByteArrayContent(array);
    imageContent.Headers.ContentType = MediaTypeHeaderValue.Parse("audio/*");
    requestContent.Add(imageContent, "audio", "audio.wav");
    var values = new Dictionary<string, string>
    {
        { "token", "b53b99534a137a71513548091271c44c" },
    };
    var content = new FormUrlEncodedContent(values);
    requestContent.Add(content);
    var response = await client.PostAsync("localhost", requestContent);
    var responseString = await response.Content.ReadAsStringAsync();
    txtbox.Text = responseString.ToString();
}

Answer 1

这是我用来发布表单信息和csv文件的代码

using (var httpClient = new HttpClient())
{
    var surveyBytes = ConvertToByteArray(surveyResponse);

    httpClient.DefaultRequestHeaders.Add("X-API-TOKEN", _apiToken);
    httpClient.DefaultRequestHeaders.Accept.Add(new MediaTypeWithQualityHeaderValue("application/json"));

    var byteArrayContent =   new ByteArrayContent(surveyBytes);
    byteArrayContent.Headers.ContentType = MediaTypeHeaderValue.Parse("text/csv");

    var response = await httpClient.PostAsync(_importUrl, new MultipartFormDataContent
    {
        {new StringContent(surveyId), "\"surveyId\""},
        {byteArrayContent, "\"file\"", "\"feedback.csv\""}
    });

    return response;
}

这是针对.net 4.5的.

请注意MultipartFormDataContent中的\".MultipartFormDataContent中存在一个错误.

在4.5.1中,MultipartFormDataContent使用正确的引号包装数据.

更新:此错误的链接不再有效,因为已退休的Microsoft Connect.