Question

我有以下情况：用户选择了产品，检索了产品记录并设置了延期交货标志。我想问用户是否想要将其包含在订单中。我似乎无法在IF语句中找到任何证明它的例子。

我的VB代码片段：

    Dim backorder = myDataTable.Rows(0)("backorder").ToString()
    If backorder = "True" And <somehow ask user it they want to order anyway> Then
       'do something
    End If

我在aspx文件中的Javascript：

    <script type = "text/javascript">
     function Confirm() {
         var confirm_value = document.createElement("INPUT");
         confirm_value.type = "hidden";
         confirm_value.name = "confirm_value";
         if (confirm("Selected item is on temporary back order. Do yuou want to include it on this order?")) {
             confirm_value.value = "Yes";
         } else {
             confirm_value.value = "No";
         }
         document.forms[0].appendChild(confirm_value);
     }
</script>

我可以通过javascript读取从VB添加到页面的变量，但无法确定如何调用javascript以提示用户。出于某种原因，我无法理解这一点。请举例说明。

Answer 1

使用RegisterStartupScript方法：

Sub ProcessOrder()

    'Your code to process the selected products here...
    Dim orderAnyway As string = hdnConfirmResponse.Value.Trim()
    If selectedItem.BackOrdered Then            
        If orderAnyway = "" Then
            Dim cs As ClientScriptManager = Page.ClientScript

            ' Define the name and type of the client scripts on the page.
            Dim csname1 As String = "ConfirmScript"
            Dim cstype As Type = Me.GetType()

            ' Check to see if the startup script is already registered.
            If (Not cs.IsStartupScriptRegistered(cstype, csname1)) Then
                Dim cstext1 As String = "Confirm();"
                cs.RegisterStartupScript(cstype, csname1, cstext1, True)
            End If
        Else
           If orderAnyway = "yes" Then 
               'ADD THE BACKORDERED ITEM SINCE THEY CONFIRMED 
           End If 
        End If
    End If

End Sub

Answer 2

我讨厌回答我自己的问题，但这最终有效。混合了mjw的回答以及对javasvript尝试的更多研究。我没有让JS创建隐藏字段，而是将其添加到HTML

    <asp:HiddenField  runat="server" id ="confirm_value"/>

新VB：

    If myDataTableFrame.Rows.Count > 0 Then
                Dim backorder = myDataTableFrame.Rows(0)("backorder").ToString()
                If backorder = "True" And confirm_value.Value <> "Yes" Then
                    Dim cs As ClientScriptManager = Page.ClientScript
                    ' Check to see if the startup script is already registered.
                    If (Not cs.IsStartupScriptRegistered(Me.GetType(), "ConfirmScript")) Then
                        Dim cstext1 As String = "Confirm();"
                        cs.RegisterStartupScript(Me.GetType(), "ConfirmScript", "Confirm();", True)
                    End If
                    Return
                Else
                    confirm_value.Value = "No"
                    ...

新Javascript：请参阅ASP.NET set hiddenfield a value in Javascript如果他们回答了＆＃34; OK＆＃34;

，还会添加按钮。

<script type = "text/javascript">
     function Confirm() {
         if (confirm("Selected item is on temporary back order. If you want to include it on this order click OK, then resubmit it?")) {
          //had to resort to this to find hidden field rather than document.getElementById('confirm_value')
             var x = document.getElementById('<%= confirm_value.ClientID%>');
             x.value = 'Yes';
             //re-click the button
             document.getElementById('<%=bttnadd.ClientID%>').click();
         } else {
             var x = document.getElementById('<%= confirm_value.ClientID%>');
             x.value = 'No';
         }
     }
</script>

在使用VB代码隐藏的ASP中，如何从VB向用户呈现是/否对话框

2 个答案: