从 DetailsView 按钮单击中捕获编辑和更新事件

Question

在允许插入、编辑和删除的 ASP.Net/VB.Net DetailsView 上，我们希望捕获当用户单击详细信息视图的"编辑"按钮和"更新"按钮时发生的事件。

我们希望在 VB.Net 代码隐藏文件中捕获这些事件和事件处理程序。

你能用示例代码告诉我怎么做吗？

*更新*

我尝试了此编码，但在单击"编辑"按钮时出现以下错误：

Unable to cast object of type 'System.Web.UI.WebControls.DetailsView' 
to type 'System.Web.UI.WebControls.DetailsViewRow'.

这是显示"编辑"按钮的标记中的编码：

<asp:DetailsView 
    ID="DetailsViewDetails" 
    runat="server" 
    AutoGenerateRows="False" 
    Height="50px" 
    Width="268px" 
    DataSourceID="SqlDataSourceDetails"
    DataKeyNames="ID"
    OnItemCommand="DetailsViewDetails_ItemCommand">
    <Fields>
        <asp:TemplateField ShowHeader="False">
            <EditItemTemplate>
                <asp:Button ID="ButtonUpdate" runat="server" CausesValidation="True" 
                    CommandName="Update" Text="Update"  />
                &nbsp;<asp:Button ID="ButtonCancelUpdate" runat="server" CausesValidation="False" 
                    CommandName="Cancel" Text="Cancel" />
            </EditItemTemplate>
            <InsertItemTemplate>
                <asp:Button ID="ButtonInsert" runat="server" CausesValidation="True" 
                    CommandName="Insert" Text="Insert" />
                &nbsp;<asp:Button ID="ButtonCancelInsert" runat="server" CausesValidation="False" 
                    CommandName="Cancel" Text="Cancel" />
            </InsertItemTemplate>
            <ItemTemplate>
                <asp:Button ID="ButtonEdit" runat="server" CausesValidation="False" 
                    CommandName="Edit" Text="Edit" />
                &nbsp;<asp:Button ID="ButtonNew" runat="server" CausesValidation="False" 
                    CommandName="New" Text="New" />
                &nbsp;<asp:Button ID="ButtonDelete" runat="server" CausesValidation="False" 
                    CommandName="Delete" Text="Delete" />
                    <AjaxToolKit:ConfirmButtonExtender ID="deleteButtonConfirmation" 
                        runat="server" 
                        ConfirmText='<%# "You are about to remove: " & vbcr & 
                            Eval("Forename") & vbcr & Eval("Surname") & "!!!" &
                            vbcrlf & "Are you sure you want to do this?" & vbcrlf &
                            "Clicking the OK button will delete this parent." %>'
                        Enabled="True" 
                        TargetControlID="ButtonDelete">
                    </AjaxToolKit:ConfirmButtonExtender>
            </ItemTemplate>
        </asp:TemplateField>

这是代码隐藏文件中的处理程序：

Protected Sub DetailsViewDetails_ItemCommand(sender As Object, e As System.Web.UI.WebControls.DetailsViewCommandEventArgs)
    Dim row As DetailsViewRow = DirectCast(DirectCast(e.CommandSource, Control).NamingContainer, DetailsViewRow)
    Select Case e.CommandName
        Case "Add"
        Case "Edit"
            ' Do this when going into edit mode so changes to the panent's tuition total balance can be updated.
            '---------------------------------------------------------------------------------------------------
            dcmOriginalRegistrationFee = GetValueFromTextBoxRegistrationFee()
        Case "Delete"
    End Select
End Sub

我们在 Dim 语句上得到错误。

Answer 1

您可以使用适当的CommandName使用它ItemCommand事件：

<asp:DetailsView ID="DetailsView1" runat="server"  
    OnItemCommand="DetailsView1_ItemCommand" 
    <Fields>
       <asp:BoundField  DataField="IdField" HeaderText="ID" />
       <asp:BoundField  DataField="NameField" HeaderText="Name" />
       <asp:ButtonField CommandName="Add" Text="Add Something" />
       <asp:ButtonField CommandName="Edit" Text="EditSomething" />
       <asp:ButtonField CommandName="Delete" Text="Delete Something" />
    </Fields>
</asp:DetailsView>

在代码隐藏中：

Protected Sub DetailsView1_ItemCommand(sender As Object, e As System.Web.UI.WebControls.DetailsViewCommandEventArgs)
    Select Case e.CommandName
        Case "Add"
        Case "Edit"
        Case "Delete"
    End Select
End Sub

Answer 2

定义一个函数来处理事件。

事件列在这里：http://msdn.microsoft.com/en-us/library/system.web.ui.webcontrols.detailsview_events.aspx

然后，您将编写一个处理程序来捕获更新事件（在更新发生之前）：

Protected Sub detailsView1_ItemUpdating(sender As Object, e As DetailsViewUpdateEventArgs) Handles detailsView1.ItemUpdating
    'Code here
End Sub

要进行编辑，请捕获模式更改事件：

Protected Sub detailsView1_ModeChanging(sender As Object, e As DetailsViewUpdateEventArgs) Handles detailsView1.ModeChanging
    'You then check the new edit mode
    If e.NewMode = DetailsViewMode.Edit Then
        'Code here
    End If
End Sub

还可以在 DetailsView 控件的标记中添加处理程序：

<asp:DetailsView runat="server" ID="detailsView1" OnItemUpdating="detailsView1_ItemUpdating" OnModeChanging="detailsView1_ModeChanging">
....
</asp:DetailsView>

这意味着您不再需要将Handles detailsView1.ItemUpdating或Handles detailsView1.ModeChanging放在函数的末尾。