Are there any multipart/form-data parser in C# - (NO ASP)

Question

I am just trying to write a multipart parser but things getting complicated and want to ask if anyone knows of a ready parser in C#!

Just to make clear, I am writing my own "tiny" http server and need to pars multipart form-data too!

Thanks in advance, Gohlool

Answer 1

I've had some issues with parser that are based on string parsing particularly with large files I found it would run out of memory and fail to parse binary data.

To cope with these issues I've open sourced my own attempt at a C# multipart/form-data parser here

See my answer here for more information.

Answer 2

With Core now you have access to a IFormCollection by using HttpContext.Request.Form.

Example saving an image:

        Microsoft.AspNetCore.Http.IFormCollection form;
        form = ControllerContext.HttpContext.Request.Form; 

        using (var fileStream = System.IO.File.Create(strFile))
        {
            form.Files[0].OpenReadStream().Seek(0, System.IO.SeekOrigin.Begin);
            form.Files[0].OpenReadStream().CopyTo(fileStream);
        }

Answer 3

I open-sourced a C# Http form parser here.

This is slightly more flexible than the other one mentioned which is on CodePlex, since you can use it for both Multipart and non-Multipart form-data, and also it gives you other form parameters formatted in a Dictionary object.

This can be used as follows:

non-multipart

public void Login(Stream stream)
{
    string username = null;
    string password = null;

    HttpContentParser parser = new HttpContentParser(stream);
    if (parser.Success)
    {
        username = HttpUtility.UrlDecode(parser.Parameters["username"]);
        password = HttpUtility.UrlDecode(parser.Parameters["password"]);
    }
}

multipart

public void Upload(Stream stream)
{
    HttpMultipartParser parser = new HttpMultipartParser(stream, "image");

    if (parser.Success)
    {
        string user = HttpUtility.UrlDecode(parser.Parameters["user"]);
        string title = HttpUtility.UrlDecode(parser.Parameters["title"]);

        // Save the file somewhere
        File.WriteAllBytes(FILE_PATH + title + FILE_EXT, parser.FileContents);
    }
}