How To Create a Listbox with Clickable Checkboxes

• Standard, Professional, and Enterprise Editions of Microsoft Visual Basic for Windows, 32-bit only, version 4.0

SUMMARY

Many Windows programs incorporate listboxes with embedded checkboxes as part of their user interface. The References dialog in Visual Basic 4.0 is one example of this kind of listbox. This article shows how to implement a listbox with this functionality in Visual Basic 4.0 by using the ListView control.

MORE INFORMATION

The ListView control has the capability to show images and text for each item in a list. The graphics to be displayed are held in an associated ImageList control and can be checked and unchecked checkboxes or whatever images are desired.

NOTE: To use ImageList controls with the ListView control, you must associate a particular ImageList control with the Icons and SmallIcons properties, as follows:

    ListView1.Icons = ImageList1
    ListView1.SmallIcons = ImageList2

1. Start Visual Basic 4.0, 32-bit, or if it is already running, open a new project.

2. Place a ListView and an ImageList control on the form.

3. Right click on the ImageList control and select Properties. On the General tab, ensure that the '16 x 16' option button is selected. Switch to the Images tab and use the Insert Picture button to add two images to the ImageList. So that the code below will work without modification, make the first picture the 'unchecked' image, and the second the

      'checked'. Visual Basic 4.0 does not ship with images that represent
      simple checked and unchecked checkboxes. Two complementary icons that
      are included in the Icons directory beneath the Visual Basic directory
      can be used (e.g. the Trash02a.ico and Trash02b.ico icons located in
      the \Icons\Computer directory.) Or, if you have a previous version of
      Visual Basic, these icons can be easily created with the IconWorks
      sample that is included with previous versions of Visual Basic.
   
   

4. Insert these lines of code in the General Declaration section of the form.

      'store the item selected in the ItemClick event
      'for use in the DblClick event
      Private ItemClicked As ListItem
   
   

5. Add the following code into the code window for the form. The operation of the code is explained in the included comments.

      Private Sub Form_Load()
          Dim itmX As ListItem
          Dim i As Integer
   
          'loop and add 10 items to the ListView control
          'this code should be replaced by your add item code
          For i = 1 To 10
              Set itmX = ListView1.ListItems.Add()
              'set icon to unchecked
              itmX.SmallIcon = 1
              itmX.Text = "ListItem " & i
          Next i
   
          'other views will work, but will allow additional
          'behavior over a standard listbox
          ListView1.View = lvwList
   
          'display full label
          ListView1.LabelWrap = False
      End Sub
   
      Private Sub ListView1_DblClick()
   
          'toggle icon between checked and unchecked
          'use the private ItemClicked variable set in the
          'ListView1_ItemClick event
          With ItemClicked
              If .SmallIcon = 1 Then
                  .SmallIcon = 2
              Else
                  .SmallIcon = 1
              End If
          End With
      End Sub
   
      Private Sub ListView1_ItemClick(ByVal Item As ListItem)
          'since there is no ItemDblClick event, save the item
          'clicked on for use in the ListView's DblClick Event
          Set ItemClicked = Item
      End Sub
   
   

REFERENCES

Online help for ListView and ImageList controls.