求助：treeview和DataGridView数据联动
求助：treeview和DataGridView数据联动Form1中有两个控件：treeview1和DataGridView1，treeview1绑定“单位信息”表，DataGridView 1绑定“职工信息”表。
单位信息表如下：
编码 单位名称
DY101 龙塘镇中心小学
DY102 龙塘镇第二小学
DY103 龙塘镇井岭小学
……
职工信息表如下：
单位编码 职工编码 姓名 性别 身份证号
DY101 DY1010001 郑小平 男 441802000000000000
DY102 DY1020001 何凯婷 女 441802000000000000
……
选择treeview1的一个节点（单位）时，在DataGridView1中显示本节点（单位）的职工
（以下代码这个功能还未实现，求高手指点）
Imports System.Data.OleDb
Imports System.
Imports
Imports System.Text
Public Class Form1
Dim conn, conntree As New OleDbConnection
Dim da, treeda As New OleDbDataAdapter
Dim ds, treeds As New DataSet
Dim dr, treedr As OleDbDataReader
Dim dt, tredr As New DataTable()
Private Sub Form1_Load(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles MyBase.Load
Try
Dim sqltree As String
sqltree = "select * from 单位信息 order by 编码"
conntree.ConnectionString = " provider = Microsoft.ACE.OLEDB.12.0; Data Source = " & Application.StartupPath & "/staffmis.mdb"
conntree.Open()
Dim comtree As New OleDbCommand(sqltree, conntree)
treedr = comtree.ExecuteReader()
TreeView1.Nodes.Clear()
Dim tree_root As New TreeNode()
'添加根节点
tree_root.Tag = "DY"
tree_root.Text = "所有单位"
TreeView1.Nodes.Add(tree_root)
'添加二级节点，从单位信息表中获取单位名称作为二级节点
While treedr.Read()
Dim root As New TreeNode()
root.Tag = treedr.GetValue(0)
root.Text = treedr.GetValue(1)
TreeView1.Nodes(0).Nodes.Add(root)
End While
conntree.Close()
TreeView1.ExpandAll()
TreeView1.Select()
Catch
MessageBox.Show("单位信息数据库连接失败！")
End Try
Try
Dim sql As String
sql = "select * from 职工信息 order by 职工编码"
conn.ConnectionString = " provider = Microsoft.ACE.OLEDB.12.0; Data Source = " & Application.StartupPath & "/staffmis.mdb"
conn.Open()
Dim com As New OleDbCommand(sql, conn)
dr = com.ExecuteReader()
dt.Load(dr)
DataGridView1.DataSource = dt
conn.Close()
Catch
MessageBox.Show("职工信息数据库连接失败！")
End Try
With Me.DataGridView1
.ReadOnly = True
.AllowUserToAddRows = False
.Columns(0).Width = 80
.Columns(1).Width = 80
.Columns(2).Width = 130
.Columns(3).Width = 70
.Columns(4).Width = 55
.Columns(5).Width = 130
.Columns(6).Width = 80
.Columns(7).Width = 60
.Columns(8).Width = 80
.Columns(9).Width = 80
.Columns(10).Width = 80
.Columns(11).Width = 80
.Columns(12).Width = 150
.Columns(13).Width = 150
.Columns(14).Width = 80
.Columns(15).Width = 80
.Columns(16).Width = 80
.Columns(17).Width = 90
.Columns(18).Width = 90
.Columns(19).Width = 180
.Columns(20).Visible = False
End With
End Sub
Private Sub Form1_Resize(ByVal sender As Object, ByVal e As System.EventArgs) Handles Me.Resize
With Me.DataGridView1
.Width = Me.Width - 195
End With
End Sub
End Class
