<div dropzone>Drop Files Here</div>

elem.bind('drop', function (evt) {

                var files = evt.target.files || (evt.dataTransfer ? evt.dataTransfer.files : evt.originalEvent.dataTransfer.files);

                for (var i = 0, f; f = files[i]; i++) {
                    var reader = new FileReader();
                    reader.readAsArrayBuffer(f);
                    reader.onload = function (e) {
                        var filename = files[0].name;
                        var fileData = e.target.result;
                        var fd = new FormData();
                        fd.append('file', fileData);
                        $http.post('../api/**Controller**/**Function**', fd, {
                            transformRequest: angular.identity,
                            headers: { 'content-Type': 'multipart/form-data' }

                        })
                        .success(function () {
                        })
                        .error(function () {
                        });
                    };
                }
            }

[System.Web.Http.HttpPost]
        public async Task<HttpResponseMessage> uploadFile(HttpRequestMessage req)
        {
 var httpRequest = HttpContext.Current.Request;
            HttpContext.Current.Request.InputStream.Position = 0;
            Stream requestStream = await req.Content.ReadAsStreamAsync();
            HttpResponseMessage result = null;
            if (requestStream != null)
            {
                try
                {


                    string path = "**pathe + name ** " + DateTime.Now.ToString("yyyyMMdd_hhmmss") + ".txt";


                    using (FileStream fileStream = System.IO.File.Create(path, (int)requestStream.Length))
             {                        {

                        byte[] bytesInStream = new byte[requestStream.Length];
                        requestStream.Read(bytesInStream, 0, (int)bytesInStream.Length);

                        fileStream.Write(bytesInStream, 0, bytesInStream.Length);
                        result = Request.CreateResponse(HttpStatusCode.Created, "file");

                    }
                }
                catch (Exception ex)
                {
                    return result = Request.CreateResponse(HttpStatusCode.BadGateway, "Http Exception Come" + ex.Message);
                }
            }
            else
            {
                return result = Request.CreateResponse(HttpStatusCode.BadGateway, "Not eble to upload the File ");
            }
            return result;
}

------WebKitFormBoundaryicAIi22ik9VhH7nL
Content-Disposition: form-data; name="file"

[object ArrayBuffer]
------WebKitFormBoundaryicAIi22ik9VhH7nL--