ASP.NET中樹形圖的實現（2）

　　 二、增加、刪除樹節點

　　單純在Treeview 上增加、刪除、修改節點只需用Nodes屬性的Add、 Remove、等方法即可，值得注意的地方是VS.NET中Treeview的Nodes集合與VS6.0中的區別，VS6.0中的是一個大的集合，而VS.NET中的是分層的每個Node下都有Nodes屬性。增加、刪除、修改樹節點時與VS6.0相比有很大差別，特別是刪除時。

Private Sub ButAdd_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles ButAdd.Click’在選定的節點下添加子節點 Dim tmpNd As New TreeNode(), NdSel As TreeNode tmpNd.ID = GetNewId() NdSel = TreeView1.GetNodeFromIndex(TreeView1.SelectedNodeIndex)’選中的節點 tmpNd.Text = "新節點" NdSel.Nodes.Add(tmpNd) Dim myRow As DataRow myRow = ds.Tables("tree").NewRow() myRow("NODE_NAME") = tmpNd.ID myRow("NODE_DESCRIPT") = "新節點" & tmpNd.ID & "_" & NdSel.ID myRow("PARENT_NAME") = NdSel.ID ds.Tables("tree").Rows.Add(myRow) End Sub Private Sub ButDele_Click(ByVal sender As Object, ByVal e As System.EventArgs) Handles ButDele.Click’刪除選中的節點 Dim idx As String = TreeView1.SelectedNodeIndex() GetNdCol(idx).Remove(TreeView1.GetNodeFromIndex(idx)) Dim dv As New DataView(), recNo As Integer dv.Table = ds.Tables("tree") dv.RowFilter= "NODEID=" & NdId dv.Delete(0) End Sub Private Function GetNdCol(ByVal idx As String) As TreeNodeCollection ‘獲得選中節點的父節點的Nodes集合 Dim cnt As Integer, i As Integer Dim tmpNds As TreeNodeCollection Dim idxs() As String idxs = Split(idx, ".") cnt = UBound(idxs) If cnt = 0 Then tmpNds = TreeView1.Nodes Else tmpNds = TreeView1.Nodes(CInt(idxs(0))).Nodes For i = 1 To cnt - 1 tmpNds = tmpNds(CInt(idxs(i))).Nodes Next End If Return tmpNds End Function