<form id="form1" runat="server">
<div>
<asp:TextBox ID="TextBox1" runat="server"></asp:TextBox><br />
<select id="s1" name="select1">
<option>XHTML</option>
<option>CSS</option>
<option>JAVASCRIPT</option>
<option>XML</option>
<option>PHP</option>
<option>C#</option>
<option>JAVA</option>
<option>C++</option>
<option>PERL</option>
</select> br />
<asp:Button ID="Button1" runat="server" Text="O K" /></div>
</form>
如何在前台判断那个html:select控件的值不能为空,且在c#后台里取得它的值呢?知道要写js,但不知道昨写?
ddlist.options[ddlist .selectedIndex].text; //取得text值
ddlist.options[ddlist .selectedIndex].value; //取得value值
Request.From["s1"]
<select id="s1" name="select1" runat="server">
当然用js取也可以
你改成这个
<script language="javascript">
function up()
{
if(document.getElementById("s1").value=="0")
{
alert("请选择");
return false;
}
}
</script>
<select id="s1" name="select1">
<option value="0">请选择</option>
<option value="XHTML">XHTML</option>
<option value="CSS">CSS</option>
<option value="JAVASCRIPT">JAVASCRIPT</option>
<option value="XML">XML</option>
<option value="PHP">PHP</option>
<option value="C#">C#</option>
<option value="JAVA">JAVA</option>
<option value="C++">C++</option>
<option value="PERL">PERL</option>
</select>
<asp:Button ID="Button1" runat="server" Text="O K" OnClientClick="return up();"/>
<html xmlns="http://www.w3.org/1999/xhtml">
<head runat="server">
<title>Untitled Page</title> <script>
function oselect()
{
if(document.all.s1.options[document.all.s1.selectedIndex].value==0)
{
alert("请选取一具体的值!");
return false;
}
else
{
return true;
}
}
</script></head>
<body>
<form id="form1" runat="server">
<div>
<asp:TextBox ID="TextBox1" runat="server"></asp:TextBox><br />
<select id="s1" name="select1" runat="server">
<option value="0">---请选取---</option>
<option value="1">XHTML</option>
<option value="2">CSS</option>
<option value="3">JAVASCRIPT</option>
<option value="4">XML</option>
<option value="5">PHP</option>
<option value="6">C#</option>
<option value="7">JAVA</option>
<option value="8">C++</option>
<option value="9">PERL</option>
</select>
<asp:Button ID="Button1" runat="server" Text="---OK---" OnClick="Button1_Click" /></div>
</form>
</body>
</html>
C#后台
protected void Page_Load(object sender, EventArgs e)
{
this.Button1.Attributes.Add("onclick", "return oselect();");
}
//取得选中的值
protected void Button1_Click(object sender, EventArgs e)
{
if (s1.SelectedIndex > 0)
{
Response.Write(s1.Items[s1.SelectedIndex].Text);
}
}
判断值不为空貌似前面有人说了
传值可以直接用url传(test.aspx?sel=value) 后台Request.QueryString["sel"] 或者使用其他服务器控件间接取值
你代码就是<option>XHTML</option>这样的?
检查下。
没有value的话js判断不了
加了runat=“server”就和服务器控件一样
没加就用Request[""]