从Excel中读取数据，关于一列数据包含多种数据类型的问题

'打开来源数据库，返回 DataView
    Function GetDataSource() As DataView

        Dim objDT As DataTable = New DataTableDim objDV As New DataView
        Dim objDS As DataSet = New DataSet
        Dim objDA As OleDbDataAdapter

         With ofdImport
            .Filter = "XLS文件(*.xls)|*.xls"
            .FilterIndex = 1
            .Title = "打开数据来源文件"
        End With