HOWTO: Accessing ImageList from TreeView & ListView Control

Last reviewed: June 17, 1997
Article ID: Q170146

The information in this article applies to:

Microsoft Visual FoxPro for Windows, versions 5.0, 5.0a

SUMMARY

This article illustrates how images of an ImageList control can be accessed by TreeView and ListView controls programmatically.

MORE INFORMATION

This section has two code examples. The first example illustrates how ImageList images can be assigned to a TreeView control. In this example if Leaves are added to a Node of the TreeView, then a Closed Folder icon is assigned to the Node. If a node containing leaves is expanded, its icon changes to an Open Folder, and upon collapse, it changes back to the Closed Folder.

The second example shows how ImageList images can be assigned to a ListView control. In this example, when a List Item is created it is assigned a large icon. The item icons can then be toggled between a small and a large icon. For each type of icon--large and small--separate ImageList controls are used; otherwise, both types of icons appear as same size.

Following is the sample code for the first example to assign ImageList images to a TreeView:

   LVForm=CREATEOBJECT("MyLVForm")
   LVForm.SHOW
   READ EVENT

   *** Define the Form to hold and display all the controls ***
   DEFINE CLASS MyLVForm AS FORM
      LEFT=23
      HEIGHT=250
      WIDTH=425
      mndx=0
      *** Add the Control Objects to the Form ***
      ADD OBJECT ImageList1 AS MyImageList
      ADD OBJECT TreeView1  AS MyTreeView
      ADD OBJECT AddNode    AS ANCButton
      ADD OBJECT AddLeaf    AS ALCButton
      ADD OBJECT mDelete    AS DCButton
      ADD OBJECT mExit      AS ECButton
   ENDDEFINE

   *** Define ImageList to Hold Images for the TreeView Control ***
   DEFINE CLASS MyImageList AS OLECONTROL
      OLECLASS="COMCTL.ImageListCtrl.1"
      TOP=36
      LEFT=420
      PROCEDURE INIT
         THIS.OBJECT.ListImages.ADD(1,,LOADPICTURE(home()+;
               "samples\graphics\bmps\outline\closed.bmp"))
         THIS.OBJECT.ListImages.ADD(2,,LOADPICTURE(home()+;
               "samples\graphics\bmps\outline\open.bmp"))
      ENDPROC
   ENDDEFINE

   *** Define the TreeView Control ***
   DEFINE CLASS MyTreeView AS OLECONTROL
      OLECLASS="COMCTL.TreeCtrl.1"
      TOP=24
      HEIGHT=169
      WIDTH=300
      LEFT=20
      .OBJECT.LineStyle=1
      VISIBLE=.T.

      *** Set ImageList property to ImageList1 Images ***
      PROCEDURE INIT
         THIS.OBJECT.ImageList=THISFORM.ImageList1.OBJECT
      ENDPROC
      PROCEDURE nodeclick
         LPARAMETERS NODE
      ENDPROC

      *** Assign Image for Collapsed object ***
      PROCEDURE collapse
         LPARAMETERS NODE
         IF !EMPTY(NODE.IMAGE)
            NODE.IMAGE=1
         ENDIF
      ENDPROC

      *** Assign Image for Expanded object ***
      PROCEDURE expand
         LPARAMETERS NODE
         IF !EMPTY(NODE.IMAGE)
            NODE.IMAGE=2
         ENDIF
      ENDPROC
   ENDDEFINE
   *** Define the Add Node Command Button ***
   DEFINE CLASS ANCButton AS COMMANDBUTTON
      TOP=70
      LEFT=350
      HEIGHT=18
      WIDTH=59
      CAPTION="Add Node"
      VISIBLE=.T.
      PROCEDURE CLICK
         mndxtxt=""
         mndxtxt=ALLTRIM(STR(THISFORM.mndx))

         THISFORM.TreeView1.nodes.ADD(,2,mndxtxt+;
          "_",REPLICATE(mndxtxt,5),,0)
         THISFORM.mndx=THISFORM.mndx+1
         THISFORM.TreeView1.ENABLED=.T.
         THISFORM.AddLeaf.ENABLED=.T.
         THISFORM.mDelete.ENABLED=.T.
      ENDPROC
   ENDDEFINE
   *** Define the Add Leaf Command Button ***
   DEFINE CLASS ALCButton AS COMMANDBUTTON
      TOP=100
      LEFT=350
      HEIGHT=18
      WIDTH=59
      CAPTION="Add Leaf"
      VISIBLE=.T.
      ENABLED=.F.
      PROCEDURE CLICK
         so=THISFORM.TreeView1.SELECTEDITEM
         IF !ISNULL(so)
            THISFORM.TreeView1.nodes.ADD(so.INDEX,;
                      4,,"Sub"+ALLTRIM(so.TEXT),,0)
            so.IMAGE=1
         ENDIF
         THISFORM.REFRESH
      ENDPROC
   ENDDEFINE
   *** Define the Delete Command Button  ***
   DEFINE CLASS DCButton AS COMMANDBUTTON
      TOP=150
      LEFT=350
      HEIGHT=18
      WIDTH=59
      CAPTION="Delete"
      VISIBLE=.T.
      ENABLED=.F.
      PROCEDURE CLICK
         o=THISFORM.TreeView1.SELECTEDITEM
         IF !ISNULL(o)
            IF !ISNULL(o.PARENT)
               IF o.PARENT.children<2
                  o.PARENT.IMAGE=0
               ENDIF
            ENDIF
            THISFORM.TreeView1.nodes.REMOVE(o.INDEX)
         ENDIF
      ENDPROC
   ENDDEFINE
   *** Define the Exit Command Button ***
   DEFINE CLASS ECButton AS COMMANDBUTTON
      TOP=215
      LEFT=180
      WIDTH=70
      HEIGHT=25
      CAPTION="Exit"
      VISIBLE=.T.
      PROCEDURE CLICK
         THISFORM.RELEASE
         CLEAR EVENTS
      ENDPROC
   ENDDEFINE

   Following is the sample code for the Second example:

   LVForm=CREATEOBJECT("MYLVForm")
   LVForm.SHOW
   READ EVENT

   *** Define the Form that will hold and display the controls ***
   DEFINE CLASS MyLVForm AS FORM
      LEFT=23
      HEIGHT=300
      WIDTH=478
      lvitm=0
      lvitxt=''
      ADD OBJECT ImageList2 AS MyImageList1
      ADD OBJECT ImageList3 AS MyImageList2
      ADD OBJECT ListView1  AS MyListView
      ADD OBJECT ADDITEM    AS AICButton
      ADD OBJECT LSIOption  AS LSIOGroup
      ADD OBJECT mDelete    AS DButton
      ADD OBJECT MExit      AS ExButton
   ENDDEFINE

   *** Need separate ImageList Controls for Large and Small Icons of
   *** ListView otherwise both type of icons will appear as same size
   ***
   *** Define ImageList to Hold Large Icon Image for the ListView
   *** Control

   DEFINE CLASS MyImageList1 AS OLECONTROL
      OLECLASS="COMCTL.ImageListCtrl.1"
      TOP=204
      LEFT=420
      PROCEDURE INIT
         THIS.OBJECT.ListImages.ADD(1,,LOADPICTURE(home()+;
             "samples\graphics\icons\office\folder01.ico"))
      ENDPROC
   ENDDEFINE

   *** Define ImageList to Hold Small Icon Image for the
   *** ListView Control

   DEFINE CLASS MyImageList2 AS OLECONTROL
      OLECLASS="COMCTL.ImageListCtrl.1"
      TOP=264
      LEFT=420
      PROCEDURE INIT
         THIS.OBJECT.ListImages.ADD(1,,LOADPICTURE(home()+;
               "samples\graphics\bmps\outline\closed.bmp"))
      ENDPROC
   ENDDEFINE

   *** Define the ListView Class ***
   DEFINE CLASS MyListView AS OLECONTROL
      OLECLASS="COMCTL.ListViewCtrl.1"
      TOP=24
      HEIGHT=169
      WIDTH=275
      LEFT=36
      .OBJECT.LineStyle=1
      VISIBLE=.T.

   *** Set the ListView Icons property to Images in ImageList1 ***
   *** and SmallIcons property to Images in ImageList2 ***

      PROCEDURE INIT
         THIS.OBJECT.icons=THISFORM.ImageList2.OBJECT
         THIS.OBJECT.smallicons=THISFORM.ImageList3.OBJECT
      ENDPROC
   ENDDEFINE

   *** Define the Add Item Button Class ***
   DEFINE CLASS AICButton AS COMMANDBUTTON
      TOP=50
      LEFT=360
      HEIGHT=18
      WIDTH=59
      CAPTION="Add Item"
      VISIBLE=.T.
      PROCEDURE CLICK
         THISFORM.lvitm=THISFORM.lvitm+1
         THISFORM.lvitxt=ALLTRIM(STR(THISFORM.lvitm))
         x=THISFORM.ListView1.OBJECT.listitems.ADD;
            (,THISFORM.lvitxt+"_","Item"+THISFORM.lvitxt,)
         x.smallicon=1
         x.ICON=1
         THISFORM.LSIOption.ENABLED=.T.
         THISFORM.mDelete.ENABLED=.T.
         THISFORM.REFRESH
      ENDPROC
   ENDDEFINE

   *** Define the Large/Small Icon Option Group ***
   DEFINE CLASS LSIOGroup AS OPTIONGROUP
      BUTTONCOUNT = 2
      VALUE = 1
      HEIGHT = 39
      LEFT = 340
      TOP = 80
      WIDTH = 96
      Option1.CAPTION = "Large Icon"
      Option1.LEFT = 11
      Option1.TOP = 5
      Option1.WIDTH = 82
      Option1.NAME = "Option1"
      Option2.CAPTION = "Small Icon"
      Option2.LEFT = 11
      Option2.TOP = 20
      Option2.WIDTH = 82
      Option2.NAME = "Option2"
      PROCEDURE INTERACTIVECHANGE
         DO CASE
         CASE THIS.VALUE=1
            THISFORM.ListView1.OBJECT.VIEW=0
         CASE THIS.VALUE=2
            THISFORM.ListView1.OBJECT.VIEW=1
         ENDCASE
         THISFORM.REFRESH
      ENDPROC
   ENDDEFINE
   *** Define the Delete Button Class ***
   DEFINE CLASS DButton AS COMMANDBUTTON
      TOP=156
      LEFT=360
      HEIGHT=18
      WIDTH=59
      CAPTION="Delete"
      VISIBLE=.T.
      ENABLED=.F.
      PROCEDURE CLICK
         o=THISFORM.ListView1.SELECTEDITEM
         IF !ISNULL(o)
            THISFORM.ListView1.listitems.REMOVE(o.INDEX)
         ENDIF
      ENDPROC
   ENDDEFINE

   *** Define the Exit Button Class
   DEFINE CLASS ExButton AS COMMANDBUTTON
      TOP=226
      LEFT=192
      WIDTH=192
      HEIGHT=18
      WIDTH=59
      CAPTION="Exit"
      VISIBLE=.T.
      PROCEDURE CLICK
         THISFORM.RELEASE
         CLEAR EVENTS
      ENDPROC
   ENDDEFINE

REFERENCES

For more information, please see the following articles in the Microsoft Knowledge Base:

   ARTICLE-ID: Q163414
   TITLE     : Cannot Specify Icon or SmallIcon for ListView Visually

   ARTICLE-ID: Q166937
   TITLE     : Programmatically Adding Images to ImageList Control

   ARTICLE-ID: Q160921
   TITLE     : Error Using OLE Controls

   ARTICLE-ID: Q163803
   TITLE     : Cannot Set ImageList Property of Treeview Visually

Keywords : FxprgClassoop kbcode vfoxwin
Version : 5.0 5.0a
Platform : WINDOWS
Issue type : kbhowto

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Last reviewed: June 17, 1997
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