Question

我正在尝试将新行添加到gridview中但由于某种原因我在for循环中遇到了问题。

直接转到 dtCurrentTable.Rows.Add（drCurrentRow）当然有错误“'row'参数不能为null。参数名称：row”，因为 dtcurrentTable.NewRow 未执行。

为什么会这样？

 Private Sub AddNewRowToGrid()
    Dim rowIndex As Integer = 0
    If Not IsNothing(ViewState("CurrentTable")) Then

        Dim dtCurrentTable As DataTable = CType(ViewState("CurrentTable"), DataTable)
        Dim drCurrentRow As DataRow = Nothing

        If dtCurrentTable.Rows.Count > 0 Then
            For i as Integer = 1 To i <= dtCurrentTable.Rows.Count
                ' Extraem-se os valores das Textbox
                Dim box1 As TextBox = Dados.Rows(rowIndex).Cells(0).FindControl("Artigo")
                Dim box2 As TextBox = Dados.Rows(rowIndex).Cells(1).FindControl("Descricao")
                Dim box3 As TextBox = Dados.Rows(rowIndex).Cells(2).FindControl("IVA")
                Dim box4 As TextBox = Dados.Rows(rowIndex).Cells(3).FindControl("PU")
                Dim box5 As TextBox = Dados.Rows(rowIndex).Cells(4).FindControl("Desconto")
                Dim box6 As TextBox = Dados.Rows(rowIndex).Cells(5).FindControl("UN")
                Dim box7 As TextBox = Dados.Rows(rowIndex).Cells(6).FindControl("Quantidade")
                Dim box8 As TextBox = Dados.Rows(rowIndex).Cells(7).FindControl("TotalLiquido")

                drCurrentRow = dtCurrentTable.NewRow

                dtCurrentTable.Rows(i - 1)("Artigo") = box1.Text
                dtCurrentTable.Rows(i - 1)("Descricao") = box2.Text
                dtCurrentTable.Rows(i - 1)("IVA") = box3.Text
                dtCurrentTable.Rows(i - 1)("PU") = box4.Text
                dtCurrentTable.Rows(i - 1)("Desconto") = box5.Text
                dtCurrentTable.Rows(i - 1)("UN") = box6.Text
                dtCurrentTable.Rows(i - 1)("Quantidade") = box7.Text
                dtCurrentTable.Rows(i - 1)("TotalLiquido") = box8.Text

                rowIndex += 1

            Next i
            dtCurrentTable.Rows.Add(drCurrentRow)
            ViewState("CurrentTable") = dtCurrentTable

            Dados.DataSource = dtCurrentTable
            Dados.DataBind()

        End If

    Else
        Response.Write("ViewState null")
    End If
    SetPreviousData()
End Sub

Answer 1

您的For循环定义错误，这就是您收到错误的原因：

For i as Integer = 1 To i <= dtCurrentTable.Rows.Count
评估为 For i as Integer = 1 To True
（因为我总是＆lt; = Rows.Count） VB翻译为
For i as Integer = 1 To -1
这意味着你的循环永远不会运行。

有应该是

For i as Integer = 1 To dtCurrentTable.Rows.Count

此外，您使用drCurrentRow = dtCurrentTable.NewRow的方式有些奇怪。当你在循环中不对它做任何事情时，为什么在循环内？它被执行多次，然后dtCurrentTable.Rows.Add(drCurrentRow)只被调用一次。

我很难纠正，因为我无法弄清楚你想要做什么，但这一点看起来很狡猾。

在gridview上插入新行时出错

1 个答案: