去世 送钱 单数 双数:谁来帮下忙,帮我解释下VB语句,倒底是什么意思,是要执行什么功能的?

来源:百度文库 编辑:高校问答 时间:2024/04/28 18:49:34
Public Sub tree()
TreeView1.Nodes.Clear
Dim nodex As Node
Dim mrc As ADODB.Recordset
Dim mrc1 As ADODB.Recordset
Dim str As String
Dim a As String
a = "年级"
'TreeView1.LineStyle = tvwRootLines
str = "select distinct 年级 from class order by 年级"
Set mrc = ExecuteSQL(str)
str = "select distinct 年级,班级 from class order by 年级,班级"
Set mrc1 = ExecuteSQL(str)
mrc.MoveFirst
Do Until mrc.EOF
mrc1.MoveFirst
Set nodex = TreeView1.Nodes.Add(, , a, mrc.Fields(0), 1, 1)
Do While Not mrc1.EOF
If mrc1.Fields(0) = mrc.Fields(0) Then
Set nodex = TreeView1.Nodes.Add(a, tvwChild, , mrc1.Fields(1), 2, 2)
End If
mrc1.MoveNext
Loop
a = a & "1"
mrc.MoveNext
Loop
mrc1.Close
mrc.Close
Set mrc = Nothing
Set mrc1 = Nothing
End Sub

基本的功能是从数据库的表中读取数据,按照先年级后班级的分类显示在treeview控件中。