{
   TreeView1.Items[0].Expand(False); //按节点索引 展开节点一级
   TreeView1.Select(TreeView1.Items[1],[]);// 按节点索引 选中节点
   
}
   TreeView1.Selected.AbsoluteIndex; //选中的节点索引号
  
  
 保存TREEVIEW状态代码
{
  SaveTreeViewExplandState(TreeView1,‘TreeView.txt‘);
}
procedure SaveTreeViewExplandState(TreeView: TTreeView; FileName: string);
var
  List: TStringList;
  i: Integer;
begin
  List := TStringList.Create;
  With TreeView do
  begin
    for i := 0 to Items.Count - 1 do
    begin
      if Items.Item[i].Expanded then
        List.Add(IntToStr(i));
    end;
    List.Add(IntToStr(Selected.AbsoluteIndex));
  end;
  List.SaveToFile(FileName);
  List.free;
end;
  
 加载TREEVIEW状态代码
{
LoadTreeViewExplandState(TreeView1, ‘abc.txt‘);
}
procedure LoadTreeViewExplandState(TreeView: TTreeView; FileName: string);
var
  List: TStringList;
  i: Integer;
begin
  List := TStringList.Create;
  with List do
  begin
    List.LoadFromFile(FileName);
 
    for i := 0 to Count - 2 do //最后一行放的是最后选中的那个节点索引
    begin
      TreeView.Items[StrToInt(List[i])].Expand(False);
    end;
    TreeView.Select(TreeView.Items[StrToInt(List[Count - 1])], []);
    free;
  end;
end;