1. L9: Qt Implementation
QTextEdit
QButton
QMainWindow
Signal and Slot

2. QTextEdit

3. QTextEdit + QButton

4. QTextEdit + QButton

5. QMainWindow: Header

6. QmainWindow: Constructor

7. QmainWindow: Save Slot

8. QmainWindow: Open Slot

9. QmainWindow:Main

10. API Reference: QIODevice
The QIODevice class is the base interface class of all I/O devices in Qt.
Mostly used IO Mode Flags are listed below.
QIODevice::NotOpen : The device is not open.
QIODevice::ReadOnly: The device is open for reading.
QIODevice::WriteOnly: The device is open for writing.
QIODevice::ReadWrite: The device is open for reading and writing.
QIODevice::Append: The device is opened in append mode, so that all data is written to the end of the file.

11. API Reference: QFileDialog::getSaveFileName
QString QFileDialog::getSaveFileName(
QWidget * parent = 0,
const QString & caption = QString(),
const QString & dir = QString(),
const QString & filter = QString(),
QString * selectedFilter = 0,
Options options = 0 )

12. API Reference: QFileDialog::getSaveFileName
Caption: The dialog's caption is set to caption. If caption is not specified, a default caption will be used.
Dir: The file dialog's working directory will be set to dir. If dir includes a file name, the file will be selected.
Filter: Only files that match the filter are shown. Multiple filters are separated with ';;'. For instance:"Images (*.png *.xpm *.jpg);;Text files (*.txt);;XML files (*.xml)"
SelectedFilter: The filter selected is set to selectedFilter.
Option: The options argument holds various options about how to run the dialog.
For instance, QFileDialog::ShowDirsOnly: Only show directories in the file dialog. By default both files and directories are shown. (Valid only in the Directory file mode.)
QFileDialog::DontResolveSymlinks: Don't resolve symlinks in the file dialog. By default symlinks are resolved.

13. API Reference: QFileDialog::getOpenFileName
QStringList QfileDialog::getOpenFileName(
QWidget * parent = 0,
const QString & caption = QString(),
const QString & dir = QString(),
const QString & filter = QString(),
QString * selectedFilter = 0,
Options options = 0 )

14. References
Qt.Nokia (2011). Qt Reference Documentation: Getting Started. Available from: [Accessed: 22 January 2011]