如何响应DropDownList选择后的值去控制另一个控件的隐藏或显示?(用Javascript实现)

Question

try something like<form id="form1" runat="server">
<asp:DropDownList id="DropDownList1" runat="Server">
<asp:ListItem Value="visible" Text="show" />
<asp:ListItem Value="hidden" Text="hide" />
</asp:DropDownList>
<asp:TextBox id="txt1" runat="server" />
</form>
<script language="C#" runat="server">
      void Page_Load(Object sender, EventArgs e)
      {
         if(!IsPostBack)
         {
            DropDownList1.Attributes["onchange"] = "javascript:showText()";
            RegisterStartupScript("Startup", "<script language='javascript'>function window.onload(){showText();}</" + "script>");         }
      }
       
</script>
<script language="javascript">
function showText()
{
  document.all("txt1").style.visibility = document.all("DropDownList1").value;
}
</script>

Answer 1

sorry, comment out the following line, :-)
 if(!IsPostBack)
===>
// if(!IsPostBack)

Answer 2

To:saucer(思归, MS .NET MVP) 
烦老兄看一下,
"编译提示：无法得到 visibility 属性"

Answer 3

设置visibility或display
到javascript区搜索一下嘛

Answer 4

document.all("txt1").style.visibility ??
中存在'style'的属性吗？

Answer 5

<form id="Form1" runat="server">
<asp:DropDownList id="DropDownList1" runat="Server">
<asp:ListItem Value="show" Text="show" />
<asp:ListItem Value="hidden" Text="hide" />
</asp:DropDownList>
<asp:TextBox id="txt1" runat="server" />
</form>
<script language="C#" runat="server">
      void Page_Load(Object sender, EventArgs e)
      {
         if(!IsPostBack)
         {
            DropDownList1.Attributes.Add("onchange","f_show(this)");
         }
      }
       
</script>
<script language="javascript">
function f_show(obj)
{
    if (obj.value=="hidden")
    {
        document.all.txt1.style.display ="none";
    }
    else
    {
       document.all.txt1.style.display="";
    } 
}
</script>
以上代码经过测试，并且扩展性好一点