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我想寫一個mdb到CVS轉換器與VB.NET。 我想要得到的列標題使用oledbdata讀者的名字,這裏是我的代碼到目前爲止vb.net對象變量或與塊變量未設置,OleDbDataReader
Public Cheadernames As Array
Public firstRead As Boolean = False
Public columnCount
Dim connectionstring = "Provider=Microsoft.ACE.OLEDB.12.0;Data Source=" & strfilename
Dim queryString = "SELECT * FROM products"
Dim connection As New OleDbConnection(connectionstring)
Dim command As New OleDbCommand(queryString, connection)
connection.Open()
Dim reader As OleDbDataReader = command.ExecuteReader()
While reader.Read
If firstRead Then
columnCount = reader.FieldCount()
firstRead = False
For i = 0 To columnCount - 1
Cheadernames(i) = reader.GetName(i) ' i am getting an error with this line
Console.WriteLine(Cheadernames(i))
Next
End If
,所以我試圖把所有的列標題名在一個數組,但註釋行給了我這個錯誤「對象變量或帶塊變量未設置「
您的問題是,Cheadernames返回數組不會初始化。 您需要首先使用返回數組(應該初始化),然後返回該數組。看看http://www.dotnetperls.com/array-vbnet和返回數組部分。 – 2012-08-08 04:24:44