NSURLSessionUploadTask will ignore the http body.
You can add the file that you want to upload to your dataSend object along with the parameter that you already have. Then write dataSend to a local file. Finally create an uploadTask with the url of that local file.
The tricky part is to prepare that dataSend object. you can first try using NSURLConnection to send a post request. then migrate your code from NSURLConnection to NSURLSession using upload task.