qdatastream 使用方法介绍，及介绍一些例子。-qdatastream use descr iption, and introduce some examples.

The QDataStream class provides serialization of binary data to a QIODevice Source Code for Linux.

The user is then asked to select an image file using QFileDialog::getOpenFileName(). The selected file is loaded into a QImage. Using a QImage lets us ensure that the selected file is a valid image, and it also allows us to immediately display the im