主题：[求助]从字符串“”到类型“Single”的转换无效。 这个怎么办

1、把这个代码删除后测试

DataTables("订单临时表").DataCols("系统单号").RaiseDataColChanged()

2、把这个代码删除后测试

dr2(Cols2(i)) = dr1(Cols1(i))

测试了一下，代码没问题。应该是你datacolchanged事件有问题导致的。

算是bug吧。换一种方式导入，如

Dim dlg As New OpenFileDialog
dlg.Filter = "Excel文件|*.xls;*.xlsx"
If dlg.ShowDialog =DialogResult.OK Then
    Dim t As Table = Tables("订单")
    t.StopRedraw()
    Dim Book As New XLS.Book(dlg.FileName)
    Dim Sheet As XLS.Sheet = Book.Sheets(0)
    For n As Integer = 1 To Sheet.Rows.Count -1
        Dim r As DataRow = Nothing ' t.DataTable.Find("第一列 = '" & sheet(n, 0).text & "'")
        If r Is Nothing Then r = t.DataTable.AddNew()
        For i As Integer = 0 To sheet.Cols.Count -1
            Dim cname As String = sheet(0, i).text
            If cname = "旺旺/昵称" Then
                r("客户id") = sheet(n, i).Text
            End If
            If t.Cols.Contains(cname) Then
                r(cname) = sheet(n, i).Text
            End If
        Next
    Next
    t.ResumeRedraw()
End If