treeview 展开所有的子节点？

Question

public partial class DepartManger : DevComponents.DotNetBar.Office2007Form我在窗体左边放置一个treeview 用来显示部门。但是当加载部门信息后。treeview却没有全部打开子节点  private void CreateTree()
        {
            //this.lidepartment.Items.Clear();
            this.tvDepartMent.Nodes.Clear();
            DataSet ds = new DataSet();
            ds = dmo.SelectDepartMsg();
            if (ds != null)
            {
                data = ds.Tables[0];
            }
            else { return; }
            dv = data.DefaultView;
            dv.Sort = "parentID asc";
            DataRowView[] arrDRV = dv.FindRows(0);
            if (arrDRV.Length == 0) return;
            TreeNode tnNew = null;
            this.tvDepartMent.Nodes.Add("sss");
            foreach (DataRowView drv in arrDRV)
            {
                tnNew = this.tvDepartMent.Nodes[0].Nodes.Add(drv.Row["DepartName"].ToString());
                tnNew.Tag = drv.Row["DepartID"].ToString();
                CreateTreeNode(ref tnNew);
            }
            this.tvDepartMent.SelectedNode = tvDepartMent.Nodes[0];
            this.tvDepartMent.Nodes[0].ExpandAll();
        }
        private void CreateTreeNode(ref TreeNode tnParent)
        {
            DataRowView[] arrDRV = dv.FindRows(tnParent.Tag);
            if (arrDRV.Length == 0) return;
            TreeNode tnNew = null;
            foreach (DataRowView drv in arrDRV)
            {
                tnNew = tnParent.Nodes.Add(drv.Row["DepartName"].ToString());
                tnNew.Tag = drv.Row["DepartID"].ToString();
                CreateTreeNode(ref tnNew);
            }
        }
这个是不是跟我窗体继承DevComponents.DotNetBar.Office2007Form 这个有关系。请问怎么解决？

Answer 1

foreach (DataRowView drv in arrDRV)
            {
                tnNew = this.tvDepartMent.Nodes[0].Nodes.Add(drv.Row["DepartName"].ToString());
                tnNew.Tag = drv.Row["DepartID"].ToString();
                CreateTreeNode(ref tnNew);
                tnNew.expand();
            }
让每个节点展开

Answer 2

找找treeview的一个属性，好像有一个属性可以控制这个的！

Answer 3

treeView1.ExpandAll();//展开所有结点

Answer 4

treeView1.ExpandAll();在最后加上就行了

Answer 5

想让那个根结点展开，就设置：TreeView1.Node[0].Expand();