Question

Dim Current As String
Current = Directory.GetCurrentDirectory()
con.ConnectionString = "PROVIDER = Microsoft.Jet.OLEDB.4.0;Data Source = " & Current & "\SchoolMaticsDatabase.mdb"
con.Open()
TabSelect()
con.Close()

Private Sub TabSelect()
        Select Case TabControl1.SelectedIndex
            Case Is = 0
                TabDay = "Monday"
            Case Is = 1
                TabDay = "Tuesday"
            Case Is = 2
                TabDay = "Wednesday"
            Case Is = 3
                TabDay = "Thursday"
            Case Is = 4
                TabDay = "Friday"
            Case Is = 5
                TabDay = "Saturday"
            Case Is = 6
                TabDay = "Sunday"
        End Select
        ds.Clear()
        sql = "SELECT [Forename],[Surname],[Subject Speciality 1],[Subject Speciality 2],[Subject Speciality 3],[Subject Speciality 4],[Subject Speciality 5],[Subject Speciality 6]," & StartTime & "," & EndTime & ",[Spec1],[Spec2],[Spec3],[Spec4],[Spec5],[Spec6] FROM [Staff] WHERE " & TabDay & " LIKE 'T'"
        da = New OleDb.OleDbDataAdapter(sql, con)
        da.Fill(ds, "SchoolMaticsDatabase")
End Sub

da.fill（DS， “SchoolMaticsDatabase”）＆GT;＆GT;＆GT;这行代码出现错误。

如果更改了选项卡索引，则还会调用子TabSelect（）。另一件事是程序检查星期几并正确显示与当天相对应的选项卡。星期一这个代码工作正常，只要它在星期二达到这个错误就会出现。

Answer 1

尝试将conn作为参数传递给TabSelect（）函数。 TabSelect(ByRef OleDbConnection conn)由于你正在玩全局变量

，这可能是一个范围问题

VB.NET错误：“ConnectionString属性尚未初始化。”

1 个答案: