Setting the Application Icon
The application icon, typically displayed in the upper left corner of the
application top-level windows, can in Qt be set by using the
QWidget::setIcon() method on the top-level widgets.
However, in order to change the icon of the executable application file
itself, as it is presented on the desktop (i.e. prior to application
execution), it is necessary to employ another, platform-dependent
technique.
Setting the Application Icon on Windows
First, create an ICO format bitmap file that contains the icon image. This
can be done with e.g. Microsoft Visual C++: Select "File->New...", then
select the "File" tab in the dialog that appears, and choose "Icon". (Note
that you do not need to load your application into Visual C++; here we are
only using its icon editor).
Store the ICO file in the source code directory of your application, say
with the name "myappico.ico". Then, create a text file called
e.g. "myapp.rc", and let it contain this single line of text:
IDI_ICON1 ICON DISCARDABLE "myappico.ico"
Lastly, assuming you are using tmake to generate your makefiles, add this
line to your "myapp.pro" file:
RC_FILE = myapp.rc
Regenerate your makefile and your application. The .exe file will now be
represented with your icon in e.g. Explorer.
If you do not use tmake, the necessary steps are: First, run the "rc"
program on the .rc file, then link your application with the resulting
.res file.
