These forms are processed at run-time to produce dynamically-generated user interfaces. In order to generate a form at run-time, a resource file containing a .ui file is needed. Applications that use the form handling classes need to be configured to be built against the QtUiTools module. This is done by including the following declaration in a qmake project file to ensure that the application is compiled and linked appropriately. A form loader object, provided by the QUiLoader class, is used to construct the user interface. This user interface 
can be retrieved from any QIODevice; for example, a QFile object can be used to obtain a form stored in a project's resources. The QUiLoader::load() function takes the user interface description contained in the file and constructs the form widget.