I want to make an application which can draw object
relationship like UML. for example , after i made the replationship
between two object (draw line), when i drag one object , the line
will be updated automatically .And when i select the connect line ,
this line object will be selected also .
It seems that ,the Grpahic's drawline method is not the
correct choice , how can i do for that ? Make a new control ?