It could be slow due to nature of BlueTooth connection. What kind of connection you are using?
Also, seems you are using a wrong method to print your label. The sendFileContents method is intended to send some file to printer to store it there, not to print it. To print your label you need to use thePrinterConnection.write() method as it shown here: TcpConnection (Zebra API (build v2.14.5097))
Software Engineer, Kutir Mobility
Posted on behalf of Zebra Technologies
I forgot to say that I am using USB cable connection in ZQ520. That “thePrinterConnection.write” method way to do helps a lot, now the printing time is about one second! I thougth that I do something wrong because the printing time was so long, about 20 seconds. Now it works very fine!
Thank you for help and very fast response to this e-mail question.