The LayoutChanged event notifies your application once a column is resized or moved by drag and drop. Also, the LayoutChanged event may be fired if the item's position is changed by drag and drop using the AutoDrag property. 

private void LayoutChanged(object sender)
{
}

Private Sub LayoutChanged(ByVal sender As System.Object) Handles LayoutChanged
End Sub

private void LayoutChanged(object sender, EventArgs e)
{
}

void OnLayoutChanged()
{
}

void __fastcall LayoutChanged(TObject *Sender)
{
}

procedure LayoutChanged(ASender: TObject; );
begin
end;

procedure LayoutChanged(sender: System.Object; e: System.EventArgs);
begin
end;

begin event LayoutChanged()
end event LayoutChanged

Private Sub LayoutChanged(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles LayoutChanged
End Sub

Private Sub LayoutChanged()
End Sub

Private Sub LayoutChanged()
End Sub

LPARAMETERS nop

PROCEDURE OnLayoutChanged(oGrid)
RETURN

<SCRIPT EVENT="LayoutChanged()" LANGUAGE="JScript">
</SCRIPT>

<SCRIPT LANGUAGE="VBScript">
Function LayoutChanged()
End Function
</SCRIPT>

Procedure OnComLayoutChanged 
	Forward Send OnComLayoutChanged 
End_Procedure

METHOD OCX_LayoutChanged() CLASS MainDialog
RETURN NIL

void onEvent_LayoutChanged()
{
}

function LayoutChanged as v ()
end function

function nativeObject_LayoutChanged()
return

Because the LayoutChanged event can occur for different reasons, you can identify the action that caused it by saving the ItemFromPoint and/or ColumnFromPoint during the MouseDown event. The following VB sample shows how:

Dim iItemFromPointMouseDown As Long
Dim iColumnFromPointMouseDown As Long

Private Sub Form_Load()
    iItemFromPointMouseDown = 0
    iColumnFromPointMouseDown = -1
End Sub

Private Sub Grid1_LayoutChanged()
    If (iItemFromPointMouseDown <> 0) Then
            Debug.Print "Items section changed"
        Else
        If (iColumnFromPointMouseDown <> -1) Then
            Debug.Print "Columns section changed"
        Else
            Debug.Print "Others"
        End If
    End If
    iItemFromPointMouseDown = 0
    iColumnFromPointMouseDown = -1
End Sub

Private Sub Grid1_MouseDown(Button As Integer, Shift As Integer, X As Single, Y As Single)
    Dim c As Long, hit As HitTestInfoEnum
    With Grid1
        iItemFromPointMouseDown = .ItemFromPoint(-1, -1, c, hit)
        iColumnFromPointMouseDown = .ColumnFromPoint(-1, -1)
    End With
End Sub

The sample displays:

• "Columns section changed" if any change occurs in the Columns section, like moving a column to a new position or resizing the column.
• "Items section changed", if the user drags an item to a new position using the AutoDrag property on exAutoDragPosition, exAutoDragPositionKeepIndent and exAutoDragPositionAny

You can use the LayoutChanged event to save the columns position and size for future use. Use the Width property to retrieve the column's width. Use the Position property to retrieve the column's position. The Visible property specifies whether a column is shown or hidden. Use the ColumnAutoResize property to specify whether the visible columns fit the control's client area.

• Avoiding resizing the control under a specified width, like in the sample:

Private Sub Form_Resize()
On Error Resume Next
    If ScaleWidth / Screen.TwipsPerPixelX > 64 Then
        With Grid1
            .Left = 0
            .Top = 0
            .Width = ScaleWidth
            .Height = ScaleHeight
        End With
    End If
End Sub

• Using the LayoutChanged event to store the columns proportions manually. The following sample holds the columns proportions when LayoutChanged event is fired. The sample ensures that the proportions are saved only when the user resizes on of the control's columns, not when the user resizes the entire control. The proportions are kept by the Data property of the Column object.

  Option Explicit
  Dim nFit As Long
  Private Declare Function PeekMessage Lib "user32" Alias "PeekMessageA" (lpMsg As MSG, ByVal hwnd As Long, ByVal wMsgFilterMin As Long, ByVal wMsgFilterMax As Long, ByVal wRemoveMsg As Long) As Long
  Private Declare Function TranslateMessage Lib "user32" (lpMsg As MSG) As Long
  Private Declare Function DispatchMessage Lib "user32" Alias "DispatchMessageA" (lpMsg As MSG) As Long
  Private Const PM_REMOVE = &H1
  Private Type POINTAPI
          x As Long
          y As Long
  End Type
  Private Type MSG
      hwnd As Long
      message As Long
      wParam As Long
      lParam As Long
      time As Long
      pt As POINTAPI
  End Type
  
  Private Sub Form_Load()
      nFit = 0
      
      onGridResize Grid1
  End Sub
  
  Private Sub Form_Resize()
  On Error Resume Next
      nFit = nFit + 1
      With Grid1
          .Left = 0
          .Top = 0
          .Width = ScaleWidth
          .Height = ScaleHeight
      End With
      fit Grid1
     
      nFit = nFit - 1
  End Sub
  
  Private Sub Grid1_LayoutChanged()
      If (nFit = 0) Then
          onGridResize Grid1
      End If
  End Sub
  
  Private Sub fit(ByVal g As EXGRIDLibCtl.Grid)
      nFit = nFit + 1
      With g
          If (.ColumnAutoResize) Then
              .BeginUpdate
              .ColumnAutoResize = False
              Dim c As EXGRIDLibCtl.Column
              For Each c In .Columns
                  c.Width = c.Data
              Next
              .ColumnAutoResize = True
              .EndUpdate
          End If
      End With
      waitToProcessMessages
      nFit = nFit - 1
  End Sub
  
  Private Sub onGridResize(ByVal g As EXGRIDLibCtl.Grid)
      Dim c As Object
      With g
          If (.ColumnAutoResize) Then
              For Each c In .Columns
                  c.Data = c.Width
              Next
          End If
      End With
  End Sub
  
  Private Sub waitToProcessMessages()
      Dim m As MSG
      While PeekMessage(m, 0, 0, 0, PM_REMOVE)
          TranslateMessage m
          DispatchMessage m
      Wend
  End Sub