如下，想把新增的datarow加入到一个空集合。但是 xinrows.add(dr)这里出错，显示未将对象引用设置到对象的实例。MessageBox.Show(1）正常， MessageBox.Show(2)没显示。
Dim xinrows As List(Of DataRow) For i As Integer = 0 To 100
Select Case sheet(0, i).Text.Trim
Case ""
Exit For
Case "检验单号"
checkNO = sheet(1, i).Text
Case "批号"
batchno = sheet(1, i).Text
Case Else
Dim dr As DataRow = DataTables("QC数据").AddNew
dr("文件名称") = FileSys.GetName(file)
dr("修改日期") = ifo.LastWriteTime
dr.save
MessageBox.Show(1)
xinrows.add(dr)
MessageBox.Show(2) End Select
Next
MessageBox.Show(3)
For Each dr As DataRow In xinrows
dr("") = batchno
Next