主题：从关联表中创建目录树，需要筛选怎么办

Dim trv As WinForm.TreeView = e.Form.Controls("TreeView1")
For Each dr1 As DataRow In DataTables("员工表").DataRows
  Dim nd1 As WinForm.TreeNode = trv.nodes.Add(dr1("员工姓名"))
    For Each dr2 As DataRow In dr1.GetChildRows("客户信息")
        Dim nd2 As WinForm.TreeNode = nd1.nodes.add(dr2("施工单位"))
        For Each dr3 As DataRow In dr2.GetChildRows("工程信息")
            nd2.nodes.add(dr3("工程名称"))
        Next
    Next
Next

 

此主题相关图片如下：未命名.jpg

我想让出现在树里的员工只有销售员，其他的不想要，怎么办

For Each dr1 As DataRow In DataTables("员工表").DataRows
    If dr1("职位") = "销售员" Then
        Dim nd1 As WinForm.TreeNode = trv.nodes.Add(dr1("员工姓名"))
    End If

……

For Each dr1 As DataRow In DataTables("员工表").DataRows
   Dim nd1 As WinForm.TreeNode

 If dr1("职位") = "销售员" Then
      nd1 = trv.nodes.Add(dr1("员工姓名"))
    End If

……

谢谢您，成功了