VB.NET錯誤：「ConnectionString屬性尚未初始化。」

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」）>>>錯誤發生在這行代碼中。VB.NET錯誤：「ConnectionString屬性尚未初始化。」

如果選項卡索引被改變，子選項卡選擇（）也被調用。還有一件事是程序檢查星期幾並正確顯示與當天相對應的標籤。星期一這段代碼工作正常，只要星期二發佈了這個錯誤就會出現。

來源

2011-08-23 LionSword

代碼片段無法編譯爲給定。改進它並顯示前6行出現的內部方法。並展示你如何稱此方法。 –

需要更多信息來發布適當的答案 –

嘗試將conn作爲參數傳遞給TabSelect（）函數。 TabSelect(ByRef OleDbConnection conn)這可能是一個範圍問題，因爲你正在玩全局變量

來源

2011-08-23 01:55:33

感謝您的信息。我嘗試通過函數傳遞連接變量，但同樣的錯誤正在發生。 – LionSword

'conn'初始化在哪裏？ –

VB.NET錯誤：「ConnectionString屬性尚未初始化。」

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