We are trying to create a control template for gridviewheadercell and add the same to style for the gridviewheadercell.
Attached screen shot shows the xaml code for reference. TargetType is not identified after adding all the possible namespaces and assembly. Strange thing is we are able to do it in a fresh project, but not happening in the existing project. we tried adding fresh reference by deleting the old one, still not successful. the version we are using is 2009.3.1314.1030
Any help is appriciated.