protected void Page_Load(object sender, EventArgs e)
{
string myScript = @ "alert(document.forms[0][ 'Label1 '].value;) ";
Page.ClientScript.RegisterStartupScript(this.GetType(), "MyScript ", myScript, true);
}
<%@ Page Language= "C# " AutoEventWireup= "true " CodeFile= "Default.aspx.cs " Inherits= "_Default " %>
<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN " "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd ">
<html xmlns= "http://www.w3.org/1999/xhtml " >
<head runat= "server ">
<title id= "Title1 " runat= "server "> 无标题页 </title>
</head>
<body>
<form id= "form1 " runat= "server ">
<div>
<asp:Label ID= "Label1 " runat= "server " Text= "Label "> aaa </asp:Label>
</div>
</form>
</body>
</html>
------------------------------------------------------------------
执行后的HTML
<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN " "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd ">
<html xmlns= "http://www.w3.org/1999/xhtml " >
<head> <title>
无标题页
</title> </head>
<body>
<form name= "form1 " method= "post " action= "Default.aspx " id= "form1 ">
<div>
<input type= "hidden " name= "__VIEWSTATE " id= "__VIEWSTATE " value= "/wEPDwUKMTcyMTYyMjM5NmRkZdqwnR4d9teWOEPkUQTLVxGRQps= " />
</div>
<div>
<span id= "Label1 "> aaa </span>
<input type= "submit " name= "Button1 " value= "Button " id= "Button1 " /> </div>
<div>
<input type= "hidden " name= "__EVENTVALIDATION " id= "__EVENTVALIDATION " value= "/wEWAgL5mKTeAgKM54rGBvLIeDMJhguFT2LbZlAJJbn9It8H " />
</div>
<script type= "text/javascript ">
<!--
alert(document.forms[0][ 'Label1 '].value;)// --> <!--行22，字符40-->
</script>
</form>
</body>
</html>
行22，字符40错误：缺少 ') '
------解决方案--------------------------------------------------------
;应该写在)后面