“There's no Qt version assigned to this project for platform ”

1.find menu "Qt VS Tools", select Qt Options

2.add a new Qt version

 3. right click the target project， and select "Qt project settings"

 4.set the Qt Version

https://stackoverflow.com/questions/10452721/theres-no-qt-version-assigned-to-this-project-for-platform-win32-visual-stu/13872415