截取一个Asp.Net页面中的部分内容　作为邮件的一部分发送给用户

截取一个Asp.Net页面中的部分内容　作为邮件的一部分发送给用户

问题描述：
下面是一个Asp.Net的page

******************************************************
*Header
******************************************************
*Body
*
*
*
*
*
******************************************************
*Footer
*       Send[Button]
******************************************************
当用户点击Send后抽取body 部分的html内容当作邮件正文的一部分发给用户。

解法1：
在Send Button Click后,先执行页面中JavaScript把Body中的内容存到一个hidden filed中,然后PostBack.
Client script.
<script type="text/javascript">
function ClientGet()
{
  //result is a div.
var result = document.getElementById("result");
var hiddenInfo = document.getElementById("hiddenInfo");
//alert(result.innerText);
hiddenInfo.value = result.innerHTML;
}
</script>
Server button.
<asp:Button ID="btnSendMail" runat="server" Text="Send" OnClientClick="ClientGet();" OnClick="btnSendMail_Click"/>
private void SendMail( string body)
{
SmtpClient smtpClient = new SmtpClient();
MailMessage message = new MailMessage();
MailAddress fromAddress = new MailAddress("zhangsichu@gmail.com", "HtmlPartMail");
smtpClient.Host = "MailEXG";
//smtpClient.Port = 25;
message.From = fromAddress;
message.To.Add("zhangsichu@gmail.com");
message.Subject = "HtmlPartMail";
message.IsBodyHtml = true;
message.Body = body;
smtpClient.Send(message);
}
protected void btnSendMail_Click(object sender, EventArgs e)
{
if (string.IsNullOrEmpty(this.hiddenInfo.Value))
this.SendMail(this.hiddenInfo.Value);
}
<pages enableEventValidation="false" validateRequest="false"/>

解法2：
override page 的 Render 方法。当页面Render前用一个static的StringBuider 记住全部html
protected override void Render(HtmlTextWriter writer)
{
HtmlForMailPart = new StringBuilder();
StringWriter stringWriter = new StringWriter(HtmlForMailPart);
HtmlTextWriter innerWriter = new HtmlTextWriter(stringWriter);
base.Render(innerWriter);
innerWriter.Close();
writer.Write(HtmlForMailPart.ToString());
//base.Render(writer);
}
取得Body部分
public const string HtmlForMailPartBeginKey = "";
public const string HtmlForMailPartEndKey = "";

public string GetMailHtmlPart()
{
if (HtmlForMailPart == null)
{
return string.Empty;
}

string htmlContent = HtmlForMailPart.ToString();
int startIndex = htmlContent.IndexOf(HtmlForMailPartBeginKey);
int endIndex = htmlContent.IndexOf(HtmlForMailPartEndKey);

if (endIndex < startIndex)
{
return string.Empty;
}
htmlContent = "<table><head><style>"
+ " td { font-size: 12px }"
+ " body { font-size: 12px }"
+ "</style></head><body>"
+ htmlContent.Substring(startIndex, endIndex - startIndex)
+ "</body></html>";

return htmlContent;
}
HtmlForMailPartBeginKey
HtmlForMailPartEndKey
这两个tag放在要取得内容的头和尾。