using DevExpress.XtraGrid.Views.Grid;
using DevExpress.XtraGrid.Views.Base;

public void NavigateDetails(ColumnView inspectedView) {
    if(inspectedView == null) return;
    // Prevent excessive visual updates.
    inspectedView.BeginUpdate();
    try {
        GridView gridView = inspectedView as GridView;
        // Get the number of data rows in the View.
        int dataRowCount;
        if(gridView == null)
            dataRowCount = inspectedView.RowCount;
        else
            dataRowCount = gridView.DataRowCount;
        // Traverse View's rows.
        for(int rowHandle = 0; rowHandle < dataRowCount; rowHandle++) {
            // Place your code here to process the current row.
            // ...                    
            if(gridView != null) {                        
                // Get the number of master-detail relationships for the current row.
                int relationCount = gridView.GetRelationCount(rowHandle);                    
                // Iterate through master-detail relationships.
                for(int relationIndex = 0; relationIndex < relationCount; relationIndex++) {
                    // Store expansion status of the corresponding detail View.
                    bool wasExpanded = gridView.GetMasterRowExpandedEx(rowHandle, relationIndex);
                    // Expand the detail View.
                    if(!wasExpanded)
                        gridView.SetMasterRowExpandedEx(rowHandle, relationIndex, true);
                    // Navigate the detail View.
                    NavigateDetails((ColumnView)gridView.GetDetailView(rowHandle, relationIndex));
                    // Restore the row's expansion status.
                    gridView.SetMasterRowExpandedEx(rowHandle, relationIndex, wasExpanded);
                }
            }
        }
    }
    finally {
        // Enable visual updates.
        inspectedView.EndUpdate();
    }
}

Imports DevExpress.XtraGrid.Views.Grid
Imports DevExpress.XtraGrid.Views.Base

Public Sub NavigateDetails(ByVal inspectedView As ColumnView)
    If inspectedView Is Nothing Then Return
    ' Prevent excessive visual updates.
    inspectedView.BeginUpdate()
    Try
        Dim gridView As GridView = Nothing
        If TypeOf inspectedView Is GridView Then gridView = inspectedView
        ' Get the number of data rows in the View.
        Dim dataRowCount As Integer
        If gridView Is Nothing Then
            dataRowCount = inspectedView.RowCount
        Else
            dataRowCount = gridView.DataRowCount
        End If
        ' Traverse View's rows.
        Dim rowHandle As Integer
        For rowHandle = 0 To dataRowCount - 1
            ' Place your code here to process the current row.
            ' ...
            Try
                inspectedView.SetRowCellValue(rowHandle, inspectedView.Columns(0), rowHandle)
            Catch ex As Exception

            End Try
            If Not gridView Is Nothing Then
                ' Get the number of master-detail relationships for the current row.
                Dim relationCount As Integer = gridView.GetRelationCount(rowHandle)
                ' Iterate through master-detail relationships.
                Dim relationIndex As Integer
                For relationIndex = 0 To relationCount - 1
                    ' Store expansion status of the corresponding detail View.
                    Dim wasExpanded As Boolean = _
                      gridView.GetMasterRowExpandedEx(rowHandle, relationIndex)
                    ' Expand the detail View.
                    If Not wasExpanded Then gridView.SetMasterRowExpandedEx( _
                      rowHandle, relationIndex, True)
                    ' Navigate the detail View.
                    NavigateDetails(gridView.GetDetailView(rowHandle, relationIndex))
                    ' Restore the row's expansion status.
                    gridView.SetMasterRowExpandedEx(rowHandle, relationIndex, wasExpanded)
                Next
            End If
        Next

    Finally
        ' Enable visual updates.
        inspectedView.EndUpdate()
    End Try
End Sub