请教下Public bbb As Boolean问题
Private Sub Combo4_Change()If Trim(Combo4.Text) = "" Then
List1.Clear
List1.Visible = False
Exit Sub
End If
If bbb = True Then
List1.Clear
List1.Visible = False
Dim mrc As ADODB.Recordset
txtsql = "select DISTINCT 姓名 from xj where 学号 ='" & Trim(Combo4.Text) & "'"
Set mrc = ExecuteSQL(txtsql)
If mrc.EOF = True Then
sss = MsgBox("没有此学号!", vbExclamation + vbOKOnly, "警告")
Text2.Text = ""
Exit Sub
End If
Text2.Text = mrc.Fields(0)
Set mrc = Nothing
Exit Sub
End If
Dim rst As ADODB.Recordset
Dim str As String
str = "select 学号 from xj where 学号 like'" & Trim(Combo4.Text) & "%' and 班级='" & Trim(Combo2.Text) & "' order by 学号"
Set rst = ExecuteSQL(str)
If rst.EOF = True Then
List1.Clear
List1.Visible = False
Set rst = Nothing
Exit Sub
End If
List1.Clear
Do Until rst.EOF
List1.AddItem rst.Fields(0)
rst.MoveNext
Loop
Set rst = Nothing
List1.Visible = True
End Sub
这里的bbb是什么意思,bbb在通用声明定义Public bbb As Boolean,这里bbb的作用我不太明白,它代表的是什么意思啊