First I open a project(.cbp) in default workspace, and compile and debug( such things)...
then I close the project , and open a workspace (.workspace) , and compile , In post build step , I use $(PROJECT_DIR) , and the $(PROJECT_DIR) is still the first project directory( the first one I opened .cbp).
I click the different project in workspace , the $(PROJECT_DIR) cannot change the value to current active project .