在.NET中读取Excel - 某些列读入为null

Question

我试图从excel中读取一些数据:

If (FileUpload1.PostedFile.ContentType = "application/vnd.ms-excel") Then
                Dim filename As String = Path.GetFileName(FileUpload1.FileName)
                'Session("userid") & "-" & Date.Now()
                filepath = "\excel\" & Session("userid") & "_" & Now.Date().ToString("Mdy") & "_" & filename
                FileUpload1.SaveAs(Server.MapPath("~/") & filepath)
                ReadExcel(filepath)

            Else
                StatusLabel.Text = "Only Excel file types are accepted"
            End If

一切似乎都很好,除非其中一列有时读入为NULL.如果它是一个不同的类型,似乎会发生这种情况.我无法弄清楚它是什么.有人帮我请....

Sub ReadExcel(ByVal filepath As String)
    Dim MyConnection As System.Data.OleDb.OleDbConnection
    Dim DtSet As System.Data.DataSet
    Dim MyCommand As System.Data.OleDb.OleDbDataAdapter
    MyConnection = New System.Data.OleDb.OleDbConnection("provider=Microsoft.Jet.OLEDB.4.0;Data Source='" & Server.MapPath("~/") & filepath & "';Extended Properties=Excel 8.0;")

    DtSet = New System.Data.DataSet
    Try
        MyCommand.Fill(DtSet)
        'gwResults.DataSource = DtSet.Tables(0)
        LoopSources(DtSet)
        'gwResults.DataBind()
        MyConnection.Close()
    Catch ex As Exception
        StatusLabel.Text = "Import Excel status: The file could not be loaded. The following error occured: <br>" + ex.Message
    End Try

End Sub

Answer 1

您需要Extended Properties="Excel 8.0;IMEX=1;"在连接字符串中包含.Excel尝试通过读取前几行来确定列的数据类型.一旦它认为它知道数据类型,任何不符合该类型的东西都被强制为NULL.很烦人. IMEX=1告诉它将您的数据作为混合读取,并应解决您的问题.如果您有标题行,则还应考虑包括HDR=YES.有关详细信息,请参阅此链接:http://www.connectionstrings.com/excel.