C#_asp.net mvc 验证码功能的具体实现

@using (Html.BeginForm("Login", "HomePage",FormMethod.Post))
{
<h2>登录</h2><p class="tyg-p">欢迎访问 智慧能力</p>
<div style="margin:5px 0px;">
<input id="UserName" name="UserName" type="text" placeholder="请输入账号..." />
</div>
<div style="margin:5px 0px;">
<input id="Pwd" name="Pwd" type="password" placeholder="请输入密码..." />
</div>
<div style="margin:5px 0px;">
<input id="code" name="code" type="text" style="width:150px;" placeholder="请输入验证码..." />
<img id="CheckCodeImage" src="@Url.Content("~/Common/ValidateCode.ashx")" onclick="this.src='@Url.Content("~/Common/ValidateCode.ashx")?time='+new Date().getTime()" style="cursor:pointer;" title="看不清？换一张" alt="看不清？换一张" />
</div>
<button type="submit">登<span style="width:20px;"></span>录</button>
}