Webapi ajax formdata upload with extra parameters

Question

I'm using jQuery ajax to upload file but want to add some parameters on webapi method, here is:

var data = new FormData();
data.append("file", $("#file")[0].files[0]);
data.append("myParameter", "test"); // with this param i get 404

$.ajax({
    url: '/api/my/upload/',
    data: data,
    cache: false,
    contentType: false,
    processData: false,
    type: 'POST',
    success: function (data) {
        console.log(data);
    }
});

The Webapi controller:

public class MyController : ApiController
{
    public string Upload(string myParameter)
    {
        return System.Web.HttpContext.Current.Request.Files.Count.ToString() + " / " + myParameter;
    }
}

Without myParameter everything work but when I include myParameter on formdata and api method I get 404, any chance to make it work?

Answer 1

Posting the FormData object results in a request with content type multipart/form-data. You have to read the request content like so:

[HttpPost]
public async Task<string> Upload()
{
    var provider = new MultipartFormDataStreamProvider("C:\\Somefolder");
    await Request.Content.ReadAsMultipartAsync(provider);

    var myParameter = provider.FormData.GetValues("myParameter").FirstOrDefault();
    var count = provider.FileData.Count;

    return count + " / " + myParameter;
}

BTW, this will save the file in the path specified, which is C:\\SomeFolder and you can get the local file name using provider.FileData[0].LocalFileName;

Please take a look at MSDN code sample and Henrik's blog entry.