Creating a message box, if Dropdown answer is yes. VB.Net_问答_开发者

Creating a message box, if Dropdown answer is yes. VB.Net

开发者 https://www.devze.com 2023-02-14 20:00 出处：网络

I have a working dropdown box that gives the answers yes & no.When \"yes\" is selected I need t开发者_如何学Co create a message box that displays a simple message and allows the user to click ok,

I have a working dropdown box that gives the answers yes & no. When "yes" is selected I need t开发者_如何学Co create a message box that displays a simple message and allows the user to click ok, to get back to the survey.

I have been working with it, and tried several things but no luck. What would the code look like, and where exactly would I place it to fire at the right time. I am working in VB, with an aspx & aspx.vb page. Thanks in advance.

one sort of classic way to do this is add the onchange attribute to the DropDownList

Dim message As String = "Custom Message"
DropDownList1.Attributes.Add("onchange", "if (this.value === 'yes') alert('" + message + "');")

Remember that message boxes on the web are a client technology, so you'll have to do this via javascript, using the alert() function.

The below code should help you get something similar for your page.

<head runat="server">
    <title>Untitled Page</title>
    <style type="text/css">  

    </style>
    <script type="text/javascript">
        function ShowAlert()
        {
            var dropDownList = document.getElementById("DropDownList1");
            var dropDownListValue = dropDownList.value;
            if (dropDownListValue == "1")
            {
                alert('This is your message box!');
            }
        };
    </script> 
</head>
<body>
<form runat="server">
    <asp:DropDownList ID="DropDownList1" runat="server" onchange="ShowAlert();">
        <asp:ListItem Text="Yes" Value="1"></asp:ListItem>
        <asp:ListItem Text="No" Value="0"></asp:ListItem>
    </asp:DropDownList>
</form>    
</body>