Files （.h or .cpp）begins with a capital letter will cause a problem when making.In this case the complier will give errors like “undefined reference to `classname::staticMetaObject” 。I had add the micro “Q_OBJECT” in the begin of the class. I check the makefie.debug(or .release) and find the makefile lost some MOC file included in the SOURCE. The problem was resolved when i modified the file's names form capital letter to lower case with no other changes.The appendixs are the demos of this case.