代码如下：
1． WebForm1.aspx
<%@ Page language="c#" Codebehind="WebForm1.aspx.cs" AutoEventWireup="false" Inherits="WebApplication4.WebForm1" %>
<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.0 Transitional//EN" >
<HTML>
<HEAD>
<title>WebForm1</title>
<meta name="GENERATOR" Content="Microsoft Visual Studio .NET 7.1">
<meta name="CODE_LANGUAGE" Content="C#">
<meta name="vs_defaultClientScript" content="JavaScript">
<meta name="vs_targetSchema" content="http://schemas.microsoft.com/intellisense/ie5">
<script language="javascript">
function aa()
{
//document.all.Label1.innerHTML="Ok";
//alert("aa");
document.getElementById('Button2').click();
}
</script>
</HEAD>
<body MS_POSITIONING="GridLayout">
<form id="Form1" method="post" runat="server">
<FONT face="宋体">
<asp:Label id="Label1" style="Z-INDEX: 101; LEFT: 304px; POSITION: absolute; TOP: 64px" runat="server"></asp:Label>
<asp:Button id="Button1" style="Z-INDEX: 102; LEFT: 360px; POSITION: absolute; TOP: 136px" runat="server"
Text="Button1"></asp:Button>
<asp:Button id="Button2" style="Z-INDEX: 103; LEFT: 320px; POSITION: absolute; TOP: 208px" runat="server"
Text="Button2"></asp:Button></FONT>
</form>
</body>
</HTML>
2． WebForm1.aspx.cs
在Page_Load中
private void Page_Load(object sender, System.EventArgs e)
{
if(!IsPostBack)
{
this.Button1.Attributes.Add("onclick","aa()");
}
}
添加事件Button2
private void Button2_Click(object sender, System.EventArgs e)
{
this.Label1.Text="Ok";
}
代码非常简单
运行结果
单击”Button1”按钮,在Button2事件中添加断点如下
是能够进入Button2事件的（应该说Label1的值是”Ok”）
但结果会是
不知道Label1为空，为什么有谁可以解释一下吗？？
源代码: