Updating progress bar during copying a large file size

Question

How to update the progress bar to show the progress of copying a file because QFile documentation says:

Unlike other QIODevice implementations, such as QTcpSocket, QFile does not emit the aboutToClose(), bytesWritten(), or readyRead() signals. This implementation detail means that QFile is not suitable for reading and writing certain types of files, such as device files on Unix platforms.

I would greatly appreciate any help on this.

Answer 1

This means that you shouldn't use QFile with files that may block on reading or writing, like device files (serial ports, for example). You should use instead another QIODevice derived class (maybe write your own), like QExtSerialPort does with serial port.