在代码中隐藏div中的按钮

Question

I have a aspx page and i want to hide the button from cs file based on my some condition

My .aspx looks like :

<asp: Content Id="contentid" >
<% if (!IsRedeemCardFlowOptin)
       { %>
       <ul id="ulid" class="abc">      
       </ul>
        <div class="bcd" id ="div1">
               <div id="div2"></div>
               <div id="div3"></div>
           <div id="div4" runat="server">
                     <h4><%= m_AutoRenewInfo.NewPageContent.ArCsidOffHeader%></h4>
                     <button class="abc bcd cde" title="Button" id="buttondiv"><span>Button</span></button>  //Want to hide this button
               </div>
           </div>
 <% } %>
</asp:Content>

Now in the cs file i want to hide the button with id "buttondiv", how can i do that

In my cs file, i try this 2 things but it doesnt work

Control myDiv = (Control)FindControl("buttondiv");
myDiv.Visible = false;

Or

foreach (Control c in contentid.Controls)
{
    if (c.ID == "buttondiv")
       {
           c.Visible = false;
       }
}

Can anyone let me know

Answer 1

In order to be used as a server-side control, the button would need to be a server-side control. Add runat="server" :

<button class="abc bcd cde" title="Button" id="buttondiv" runat="server">

Then (unless you've broken the designer somehow, it's been a while since I've used Web Forms) you should have an HtmlControl object in your class that you can set without the need to "find" the control:

this.buttondiv.Visible = false;

Answer 2

Kindly keep this in css file.

#buttondiv{
display:none;
}

Or apply style inline like below:

<button class="abc bcd cde" title="Button" id="buttondiv" style="display:none"><span>Button</span></button>