asp.net中删除cookie

在web开发中Cookie是必不可少的.NET自然也有一个强大的Cookie操作类，我们用起来也非常方便，不过在使用中我们会发现一个坑爹的事情Response.Cookies.Remove删除不了Cookie。例子如下：protectedvoid Page_Load(object sender, EventArgs e)
{
if (!IsPostBack)
{
HttpCookie UserInfo = new HttpCookie("UserInfo");
UserInfo.Value = "bdstjk";
Response.Cookies.Add(UserInfo);
}

}

protectedvoid btnRemoveCookie_Click(object sender, EventArgs e)
{
Response.Cookies.Remove("UserInfo");
Response.Write("<script type=\"text/javascript\">alert(\"删除Cookie成功！\");</script>");
}

protectedvoid btnCheckCookie_Click(object sender, EventArgs e)
{
if (Request.Cookies["UserInfo"] != null)
{
Response.Write("Cookie存在，"+Request.Cookies["UserInfo"].Value);
}
else
{
Response.Write("Cookie不存在");
}
}
页面代码：<asp:Button ID="btnRemoveCookie" runat="server" Text="删除Cookie"
onclick="btnRemoveCookie_Click" />
<asp:Button ID="btnCheckCookie" runat="server" Text="检查Cookie"
onclick="btnCheckCookie_Click" />
运行代码测试，你会发现，怎么点删除按钮，cookie都存在。
那么如果我们想删除cookie应该怎么做呢？把删除cookie的代码改成如下语句：if (Request.Cookies["UserInfo"] != null)
{
Response.Cookies["UserInfo"].Expires = DateTime.Now.AddDays(-1);
}
Response.Write("<script type=\"text/javascript\">alert(\"删除Cookie成功！\");</script>");