构造函数的放置

Question

由于某些原因，在我的每个语句的以下段中，它声明csv数据不能为null，即使你看到它们创建csvData对象时它在循环中创建的是正确的位置。 / p>

        For Each thisDocument As String In documentList

            filename = Path.GetFileName(thisDocument)
            SiteId = filename.Substring(0, filename.IndexOf("_"))

            Dim orderNumbers As String()
            Dim csvData As New DataTable
            Dim importUtils As New ImportController

            filename = Path.GetFileName(thisDocument)
            orderNumbers = filename.Split("_")
            location = filename.Substring(0, 3)
            importUtils = New ImportController(cfb.TargetFolder & filename)


            csvData = importUtils.ConvertCsvToDatatable(True)

            ImportDataTableToSql(cfb.TargetFolder & filename, csvData, cfb.StoreCompany)

        Next

编辑以显示convertcsvtodatatable（）

Public Function ConvertCsvToDatatable(ByVal ColumnNames As Boolean) As DataTable
    Try
        Dim dt As New DataTable
        For Each columnName In GetColumnsfromCsv(ColumnNames, ",")
            dt.Columns.Add(columnName)
        Next
        Dim fileReader As New StreamReader(FileName)
        If ColumnNames Then
            fileReader.ReadLine()
        End If
        Dim line As String = fileReader.ReadLine
        While Not IsNothing(line)
            line = line.Replace(Chr(34), "")
            dt.Rows.Add(line.Split(","))
            line = fileReader.ReadLine
        End While
        fileReader.Close()
        Return dt
    Catch ex As Exception
        'log to file
    End Try
    Return Nothing
End Function