Image tree control

I have new dialog tree.odcl with modal dialogs Form into Form I have Image tree control  name "tree".
For an example I start LISP

(command "OPENDCL")

(DEFUN c:mytree (/ nCount)

  (dcl_Project_Load "tree" T)

  (dcl_FORM_SHOW tree_Form)

                 (dcl_TREE_ADDPARENT tree_Form_tree "slide1" "t1")

                 (dcl_TREE_ADDPARENT tree_Form_tree

                                      "slide library"

                                      "t2"

                 )

                 (dcl_TREE_ADDPARENT tree_Form_tree "slide3" "t3")

                 (dcl_TREE_ADDCHILD tree_Form_tree

                                     '(("t2" "Child1" "C1")

                                       ("t2" "Child2" "C2")

                                       ("t2" "Child3" "C3")

                                      )

                 )

                 (dcl_TREE_SELECTITEM tree_Form_tree "t1")

                 (dcl_TREE_COUNTITEMS tree_Form_tree)

        )

After start mytree on the screen of AutoCAD I see Form with Image tree control
but Image tree control empty, after closings form i have alert :
"An OpenDCL function argument processing exception has occurred!
Error: NIL value not allowed
Function: dcl_Tree_AddParent
Argument: 0 "
What do I do incorrectly?

you need to add an "Initialize" event to you form to populate the tree...

(defun c:tree_Form_OnInitialize (/)
                (dcl_TREE_ADDPARENT tree_Form_tree "slide1" "t1")
                (dcl_TREE_ADDPARENT tree_Form_tree
                                      "slide library"
                                      "t2"
                )
                (dcl_TREE_ADDPARENT tree_Form_tree "slide3" "t3")
                (dcl_TREE_ADDCHILD tree_Form_tree
                                    '(("t2" "Child1" "C1")
                                      ("t2" "Child2" "C2")
                                      ("t2" "Child3" "C3")
                                      )
                )
                (dcl_TREE_SELECTITEM tree_Form_tree "t1")
                (dcl_TREE_COUNTITEMS tree_Form_tree)
)

Thanks! Now this code works

(command "OPENDCL")

(DEFUN c:mytree (/ )

  (dcl_Project_Load "tree" T)

  (dcl_FORM_SHOW tree_Form)

  (c:tree_Form_OnInitialize)

)

    

(defun c:tree_Form_OnInitialize (/)

                 (dcl_TREE_ADDPARENT tree_Form_tree "slide1" "t1")

                 (dcl_TREE_ADDPARENT tree_Form_tree

                                      "slide library"

                                      "t2"

                 )

                 (dcl_TREE_ADDPARENT tree_Form_tree "slide3" "t3")

                 (dcl_TREE_ADDCHILD tree_Form_tree

                                     '(("t2" "Child1" "C1")

                                       ("t2" "Child2" "C2")

                                       ("t2" "Child3" "C3")

                                      )

                 )

                 (dcl_TREE_SELECTITEM tree_Form_tree "t1")

                 (dcl_TREE_COUNTITEMS tree_Form_tree)

)



(defun c:tree_Form_tree_OnClicked (/)

  (dcl_MessageBox "MyTree: code must be added to event handler\r\nc:tree_Form_tree_OnClicked" "MyTree")

)

But there was a question how to receive correct inquiry after Click on a tree controle.
Now I have only one function c:tree_Form_tree_OnClicked, for all CHILDS, and it would be necessary to me that at concrete to a clique concrete function was caused. How it to make?

Hi, Holon, if I understood you right, you want to get the item you clicked on. If so, then do:

(defun c:tree_Form_tree_OnClicked (/)

  (if (and (setq strKey (dcl_Tree_GetSelectedItem tree_Form_tree))

           (= (type strKey) 'STR)) ;; make sure that the result is a key (only if you use strings as keys)

    (princ (strcat "\nYou've selected " (dcl_tree_getitemtext tree_Form_tree strKey) "\r"))

  ); if

); c:tree_Form_tree_OnClicked 

Hope, that helps.

Fred

Thank you Fred  ;)