title: check and uncheck all the nodes of the tree view in c#
body: <p>I have the tree view in my windows application and in the tree view with the checkboxes and I have the Some "parent nodes" and some "child nodes" and i want to CHECK AND UNCHECK  the parent and child nodes at a time on clicking the "Check All" and "Uncheck All" button... How should i do this?</p>