public static void SetSortIcon(this ListView listViewControl, int columnIndex, SortOrder order)
{
IntPtr columnHeader = SendMessage(listViewControl.Handle, LvmGetheader, IntPtr.Zero, IntPtr.Zero);
for (int columnNumber = 0; columnNumber <= listViewControl.Columns.Count - 1; columnNumber++)
{
var columnPtr = new IntPtr(columnNumber);
var item = new Hditem
{
mask = Hditem.Mask.Format
};
if (SendMessage(columnHeader, HdmGetitem, columnPtr, ref item) == IntPtr.Zero)
{
throw new Win32Exception();
}
if (order != SortOrder.None && columnNumber == columnIndex)
{
switch (order)
{
case SortOrder.Ascending:
item.fmt &= ~Hditem.Format.SortDown;
item.fmt |= Hditem.Format.SortUp;
break;
case SortOrder.Descending:
item.fmt &= ~Hditem.Format.SortUp;
item.fmt |= Hditem.Format.SortDown;
break;
}
}
else
{
item.fmt &= ~Hditem.Format.SortDown & ~Hditem.Format.SortUp;
}
if (SendMessage(columnHeader, HdmSetitem, columnPtr, ref item) == IntPtr.Zero)
{
throw new Win32Exception();
}
}
}
public static extern IntPtr SendMessage(IntPtr hWnd, UInt32 msg, IntPtr wParam, ref Hditem lParam);