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ASP.NET中树形图的实现(2) myDataAdapter.Fill(ds, "tree")
End Sub
建树的基本思路是：从根节点开始递归调用显示子树
Private Sub Page_Load(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles MyBase.Load
CreateDataSet()
intiTree(TreeView1.Nodes, 0)
End Sub
Private Sub intiTree(ByRef Nds As TreeNodeCollection, ByVal parentId As Integer)
Dim dv As New DataView()
Dim drv As DataRowView
Dim tmpNd As TreeNode
Dim intId As Integer
dv.Table = ds.Tables("tree")
dv.RowFilter = "PARENTID=’" & parentId & "’"
For Each drv In dv
tmpNd = New TreeNode()
strId = drv("NODE_ID")
tmpNd.ID = strId
tmpNd.Text = drv("NODE_NAME ")
tmpNd.ImageUrl = drv("ICON").ToString
Nds.Add(tmpNd)
intiTree(Nds(Nds.Count - 1).Nodes, intId)
Next
End Sub
二、增加、删除树节点
单纯在Treeview 上增加、删除、修改节点只需用Nodes属性的Add、 Remove、等方法即可，值得注意的地方是VS.NET中Treeview的Nodes集合与VS6.0中的区别，VS6.0中的是一个大的集合，而VS.NET中的是分层的每个Node下都有Nodes属性。增加、删除、修改树节点时与VS6.0相比有很大差别，特别是删除时。
Private Sub ButAdd_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles ButAdd.Click’在选定的节点下添加子节点
Dim tmpNd As New TreeNode(), NdSel As TreeNode
tmpNd.ID = GetNewId()
NdSel = TreeView1.GetNodeFromIndex(TreeView1.SelectedNodeIndex)’选中的节点
tmpNd.Text = "新节点"
NdSel.Nodes.Add(tmpNd)
Dim myRow As DataRow
myRow = ds.Tables("tree").NewRow()
myRow("NODE_NAME") = tmpNd.ID
myRow("NODE_DESCRIPT") = "新节点" & 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’删除选中的节点
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
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