How to build 64bit Qt for windows
h1. Qt Build for 64 bit Environment on Windows with Microsoft Visual Studio
Building 64bit Qt is pretty straightforward if you have built 32bit Qt. There is no need to make change in qmake and mkspec. It has been confirmed to work up to Qt 4.7.4 at the time of this writing.
If you have built Qt before…
With Microsoft Visual Studio installed, run your build using its 64bit command prompt and follow the same steps you would for a 32bit build. Note that if you use Microsoft Visual Studio 2010, you must have its Service Pack 1 installed to avoid major build issues.
There are two easy ways to open the 64bit command prompt in 2010:
* Start->All Programs->Microsoft Visual Studio 2010->Visual Studio Tools->Visual Studio x64 Win64 Command Prompt (2010)
* Launch it from the Tools menu within Visual Studio
If you have not built Qt before…
Never fear! If I can do it, you can, too. Follow the step-by-step instructions at this link:
http://www.holoborodko.com/pavel/2011/02/01/how-to-compile-qt-4-7-with-visual-studio-2010/
A couple warnings
Keep in mind that Qt x64 is not completely supported by Nokia yet, so some bugs still exist.