如何在asp.net中使用javascript为下拉列表框设置可见的true和false

Question

<asp:DropDownList ID="ddloption" runat="server" Visible="false">
  <asp:ListItem Text="Active" Value="Active"></asp:ListItem>
  <asp:ListItem Text="D-Active" Value="D-Active"></asp:ListItem>
</asp:DropDownList>

function boxchange(dd)
{
  document.getElementById("<%= ddloption.ClientID%>").visibility = "visible";
}

ddloption是null,我得到的......你能告诉我如何使用它.

Answer 1

当你有一个runat="server" visible="false"asp控件时,它不会在html中呈现.尝试这样的事情:

<div id="wrapper" style="display: none;">
    <asp:DropDownList ID="ddloption" runat="server">
        <asp:ListItem Text="Active" Value="Active"></asp:ListItem>
        <asp:ListItem Text="D-Active" Value="D-Active"></asp:ListItem>
    </asp:DropDownList>
</div>


function boxchange(dd)
    {
          document.getElementById("wrapper").style.display = "block";
    }

Answer 2

隐藏下拉列表

  document.getElementById("<%= ddloption.ClientID%>").Style.display='none';

再次显示:

document.getElementById("<%= ddloption.ClientID%>").Style.display='';

干杯