BUG: Problem with ListView's ColumnHeader Width Property

• Microsoft Visual Basic Professional and Enterprise Editions for Windows, version 5.0

SYMPTOMS

When you programmatically set the Width of a ColumnHeader, the width of the column may actually appear larger than you expect. This presents a problem when you attempt to save the ColumnHeader Width settings so that you can restore them at a later time.

CAUSE

Internally, the Width of a ColumnHeader is padded with some predetermined constant when it is changed programmatically. This padding is not in effect if the Width of the ColumnHeader is changed through the user interface.

RESOLUTION

To work around this problem, you can set or return a ColumnHeader Width using the SendMessage API function with the LVM_SETCOLUMNWIDTH or LVM_GETCOLUMNWIDTH messages.

The constant and function declarations are as follows:

     Declare Function SendMessage Lib "user32" Alias "SendMessageA" ( _
          ByVal hwnd As Long, ByVal wMsg As Long, ByVal wParam As Long, _
          ByVal lParam As Long) As Long

     Const LVM_FIRST = &H1000
     Const LVM_GETCOLUMNWIDTH = LVM_FIRST + 29
     Const LVM_SETCOLUMNWIDTH = LVM_FIRST + 30

    SendMessage ListView1.hWnd, LVM_SETCOLUMNWIDTH, 1, 150

    Dim LVWidth as Long
    LVWidth = SendMessage (ListView1.hWnd, LVM_GETCOLUMNWIDTH, 1, 0)

STATUS

Microsoft has confirmed this to be a bug in the Microsoft products listed at the beginning of this article. We are researching this bug and will post new information here in the Microsoft Knowledge Base as it becomes available.

MORE INFORMATION

Steps to Reproduce Behavior

1. Start a new project. Form1 is created by default.

2. Click Components on the Project menu and check "Microsoft Windows Common Controls 5.0."

3. Add a ListView control and two CommandButtons to Form1.

4. Change the Caption property of Command1 to "Save Width" and the Caption property of Command2 to "Restore Width."

5. Add the following code to Form1:

         Dim iWidth1 As Long
         Dim iWidth2 As Long
   

         Private Sub Command1_Click()
            'Save the current column widths
            iWidth1 = ListView1.ColumnHeaders(1).Width
            iWidth2 = ListView1.ColumnHeaders(2).Width
         End Sub
   
         Private Sub Command2_Click()
            'Restore the column widths
            ListView1.ColumnHeaders(1).Width = iWidth1
            ListView1.ColumnHeaders(2).Width = iWidth2
         End Sub
   
         Private Sub Form_Load()
            'Add 2 column headers to ListView1 and specify an
            'initial width of 1000 for both
            With ListView1
               .View = lvwReport
               .ColumnHeaders.Add , , "Column 1", 1000
               .ColumnHeaders.Add , , "Column 2", 1000
            End With
         End Sub
   
   

6. Press the F5 key to run the project.

7. Using your cursor, resize the first column of the ListView control.

8. Click "Save Width" and then click "Restore Width," and note that the width of the first ColumnHeader is larger than the setting you specified.