[DevExpress]TreeList 显示行号

private void treeList_CustomDrawNodeIndicator(object sender, DevExpress.XtraTreeList.CustomDrawNodeIndicatorEventArgs e)
{
DevExpress.XtraTreeList.TreeList tmpTree = sender as DevExpress.XtraTreeList.TreeList;
DevExpress.Utils.Drawing.IndicatorObjectInfoArgs args = e.ObjectArgs as DevExpress.Utils.Drawing.IndicatorObjectInfoArgs;
if (args != null)
{
int rowNum = tmpTree.GetVisibleIndexByNode(e.Node) + 1;
this.treeList.IndicatorWidth = rowNum.ToString().Length * 10 + 10;
args.DisplayText = rowNum.ToString();
}
}