窗口的afterload代码：

Dim cmd As New SQLCommand
Dim dt As DataTable
cmd.C
cmd.CommandText = "SELECT DISTINCT Year(日期) As 年, Month(日期) As 月, 客户名称 From {订单}"
dt = cmd.ExecuteReader()
Dim trv As WinForm.TreeView = e.Form.Controls("TreeView1")
trv.BuildTree(dt,"年|月|客户名称")
trv.Nodes.Insert("加载所有数据",0)

\'加载第一页数据
With DataTables("订单")
    .LoadFilter = "" \'清除加载条件
    .LoadPage = 0 \'加载第一页
    .LoadTop = 10000 \'每页10000行
    .Load()
    e.Form.Controls("TextBox2").Value = 1 & "/" & .TotalPages
End With

错误提示如下：

Bin老师，加载树代码如下，也出现了错误提示：

此主题相关图片如下：123.jpg

Dim Filter As String
If e.node.Text = "加载所有数据" Then
    Filter = ""
Else
    Dim dr As DataRow = e.Node.DataRow \'获取生成此节点的行
    Dim Filter As String
    Dim Year As Integer = dr("年")
    Dim Month As Integer = dr("月")
    Dim Product As String = dr("客户名称")
    Select Case e.Node.Level
    Case 0
        Filter ="Year(日期) = " & Year
    Case 1
        Filter ="Year(日期) = " & Year & " And Month(日期) = " & Month
    Case 2
        Filter ="Year(日期) = " & Year & " And Month(日期) = " & Month & " And 客户名称 = \'" & Product & "\'"
End Select
End If
With DataTables("订单")
    .LoadFilter = Filter \'设置加载条件
    .LoadPage = 0 \'加载第一页
    .LoadTop = 10000 \'每页5行
    .Load()
    e.Form.Controls("TextBox2").Value = 1 & "/" & .TotalPages
End With

不知道该如何写代码了，Bin老师！

点击加载所有数据，会自动加载！按年月日，客户名称加载数据。

Dim dr As DataRow = e.Node.DataRow \'获取生成此节点的行
    Dim Filter As String
    Dim Year As Integer = dr("年")
    Dim Month As Integer = dr("月")
    Dim Product As String = dr("客户名称")
    Select Case e.Node.Level
    Case 0
        Filter ="Year(日期) = " & Year
    Case 1
        Filter ="Year(日期) = " & Year & " And Month(日期) = " & Month
    Case 2
        Filter ="Year(日期) = " & Year & " And Month(日期) = " & Month & " And 客户名称 = \'" & Product & "\'"
End Select

With DataTables("订单")
    .LoadFilter = Filter 
    .LoadPage = 0 
    .LoadTop = 10000 
    .Load()
    e.Form.Controls("TextBox2").Value = 1 & "/" & .TotalPages
End With

这样代码没问题，但是不知道如何加上“加载所有数据”的功能！！

这样写

    Dim dr As DataRow = e.Node.DataRow \'获取生成此节点的行
    Dim Filter As String
    Dim Year As Integer = dr("年")
    Dim Month As Integer = dr("月")
    Dim Product As String = dr("客户名称")
    Select Case e.Node.Level
    Case 0

        If e.Node.Text = "加载全部数据" Then

            Filter = ""

        Else
            Filter ="Year(日期) = " & Year

        End If
    Case 1
        Filter ="Year(日期) = " & Year & " And Month(日期) = " & Month
    Case 2
        Filter ="Year(日期) = " & Year & " And Month(日期) = " & Month & " And 客户名称 = \'" & Product & "\'"
End Select

With DataTables("订单")
    .LoadFilter = Filter 
    .LoadPage = 0 
    .LoadTop = 10000 
    .Load()
    e.Form.Controls("TextBox2").Value = 1 & "/" & .TotalPages
End With

不行啊，甜老师，还是提示：

.NET Framework 版本：2.0.50727.6413
Foxtable 版本：2014.4.16.1
错误所在事件：窗口,业务订单主窗口,TreeView1,NodeMouseClick
详细错误信息：
未将对象引用设置到对象的实例。