This
http://code.google.com/p/datacod-qt-tools/
is not my project, but it's not important.

As i understood you want to upload file and pass username and password to server, yes?

1. Get working QUpFile class
2. Create instance
3. Set head and tail using setHead and setTail methods
Qt Code: 
  1. upfile->setHead("------------hKdQAaQIL4zeExpbXAmwlW\r\nContent-Disposition: form-data; name=\"username\"\r\n\r\nusername\r\n------------hKdQAaQIL4zeExpbXAmwlW\r\nContent-Disposition: form-data; name=\"password\"\r\n\r\npassword\r\n------------hKdQAaQIL4zeExpbXAmwlW\r\nContent-Disposition: form-data; name=\"file\"; filename=\"yourFileName\"\r\nContent-Type: application/octet\r\n\r\n");
  2. upfile->setTail("\r\n------------hKdQAaQIL4zeExpbXAmwlW--");
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4. Create QNetworkRequest object and set Content-Type header like that:
Qt Code: 
  1. request.setHeader(QNetworkRequest::ContentTypeHeader, "multipart/form-data; boundary=----------hKdQAaQIL4zeExpbXAmwlW");
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5. Use
Qt Code: 
  1. QNetworkReply* QNetworkAccessManager::post(const QNetworkRequest &request, QIODevice *data)
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to post your request to server:
Qt Code: 
  1. QNetworkReply *reply = networkAccessManager->post(request, upfile);
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