Add key value pairs to MultipartFormDataContent

Question

I'm trying to upload a file and some key value pairs to a server.

The IT guy of the server tells me "When our server is receiving the request the file is showing up great, but none of the data in your key value pairs are showing up in the request (as it’s parsed by ASP.Net). I haven’t determined exactly what’s going on with that yet, but I suspect it’s getting buried by being in the dataContent object one layer deeper in the content object."

The code I'm using is below. How can I move the key value pairs "up a level"? I'm not all that savvy with networking, unfortunately.

using (var content = new MultipartFormDataContent())
{
    var dataContent = new FormUrlEncodedContent(new[]
    {
        new KeyValuePair<string, string>("Key1", "Value1"),
        new KeyValuePair<string, string>("Key2", "Value2")
    });
    content.Add(dataContent);

    using (var fileStream = File.OpenRead(filePathAndName))
    using (var fileStreamContent = new StreamContent(fileStream))
    {
        fileStreamContent.Headers.ContentDisposition = new ContentDispositionHeaderValue("form-data")
        {
            Name = "File",
            FileName = Path.GetFileName(filePathAndName)
        };
        fileStreamContent.Headers.ContentType = new MediaTypeHeaderValue("application/octet-stream");
        content.Add(fileStreamContent);
        using (var response = await client.PostAsync("api/datasets", content))
        {
            if (response.IsSuccessStatusCode)
            {
                Debug.WriteLine("Upload Success");
            }
            else
            {
                Debug.WriteLine("Upload Failed");
                Debug.WriteLine("Response : " + response);
            }
        }
    }
}

Instead of using a FormUrlEncodedContent, I also tried

content.Add(new StringContent("Value1"), "\"Key1\"");
content.Add(new StringContent("Value2"), "\"Key2\"");

but no luck

Your content.Add(new StringContent("value", "key1") (without additional quotes in the key) should be ok. You can find an example e.g. here: https://stackoverflow.com/questions/19954287/how-to-upload-file-to-server-with-http-post-multipart-form-data. — Christoph Lütjen, Oct 26 '18 at 20:53
Could you please provide some more details including how you current code looks like and what you get as response (status code, response body, exceptions?) — Christoph Lütjen, Oct 28 '18 at 18:40

score 0 · Accepted Answer · answered Oct 29 '18 at 19:07

0

Turns out the issue was server side

answered Oct 29 '18 at 19:07

jo phul

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Thanks for leaving this question and code online :) – ed22 May 08 '21 at 13:47

Add key value pairs to MultipartFormDataContent

1 Answers1