public static extern IntPtr SendMessage(IntPtr hWnd, UInt32 Msg, UInt32 wParam, ref HDITEM lParam);
private void SetColumnSortMark(SortOrder sortOrder, int columnIndex)
{
// Get HWND of Header control.
IntPtr hHeader = User32.SendMessage(
_lvwFiles.Handle, (UInt32)SysListView32.LVM_GETHEADER, 0, 0);
// Initialize HDITEM. Retrieve `HDITEM.fmt' field only.
HDITEM hdi = new HDITEM();
hdi.mask = (uint)HDItemFlags.HDI_FORMAT;
User32.SendMessage(hHeader, (UInt32)SysHeader32.HDM_GETITEMW,
(UInt32)columnIndex, ref hdi);
// Apply sorting arrow indicator flag to `HDITEM.fmt' field.
hdi.mask = (uint)HDItemFlags.HDI_FORMAT;
switch (sortOrder)
{
case SortOrder.Ascending:
hdi.fmt |= (int)HDItemFormat.HDF_SORTUP;
break;
case SortOrder.Descending:
hdi.fmt |= (int)HDItemFormat.HDF_SORTDOWN;
break;
case SortOrder.None:
hdi.fmt &= ~(int)(HDItemFormat.HDF_SORTUP | HDItemFormat.HDF_SORTDOWN);
break;
}
// Update column's format.
User32.SendMessage(hHeader, (UInt32)SysHeader32.HDM_SETITEMW,
(UInt32)columnIndex, ref hdi);
}