Question

HTML

<EditItemTemplate>
        <td>
            <asp:Label ID="LabelID" runat="server" Text='<%# Eval("sysID")%>'></asp:Label>
        </td>
        <td>
            <asp:Label ID="Labelpar" runat="server" Text='<%# Eval("parameters")%>'></asp:Label>
        </td>
        <td>
            <asp:TextBox ID="LabelValue" runat="server" Text='<%# Eval("value")%>'></asp:TextBox>
        </td>
        <td>
            <asp:Button ID="btnEdit" runat="server" Text='Update' CommandName="Update" />
            <asp:Button ID="Button1" runat="server" Text='Cancel' CommandName="Cancel" />
        </td>
</EditItemTemplate>

VB

Protected Sub OnItemUpdating(sender As Object, e As ListViewUpdateEventArgs)

    Dim svalue As TextBox = DirectCast(e.NewValues("value"), TextBox)
    Dim sParameters As String = DirectCast(e.NewValues("parameters"), Label).Text

    For Each row As DataRow In sysDT.Rows
        If row("parameters").ToString() = sParameters Then
            row("value") = svalue
            Exit For
        End If
    Next

    lvConfiguration.EditIndex = -1
    BindListView()
End Sub

如果我断点到sub，则svalue什么都不是

错误

类型＆＃39; System.NullReferenceException＆＃39;的例外情况发生在 SiteMonitor-V1.dll但未在用户代码中处理

Answer 1

首先，我使用了标签ID，后端代码中的变化很小

Dim svalue As String = TryCast(lvConfiguration.Items(e.ItemIndex).FindControl("LabelValue"), TextBox).Text
Dim sParameters As String = TryCast(lvConfiguration.Items(e.ItemIndex).FindControl("Labelpar"), Label).Text

这很好用

Listview update sub无法从aspx获取值

1 个答案: