如果页面更改或刷新，则清除标签

Question

我创建了一个电子邮件表单，当用户点击提交时。如果页面被刷新，该页面会将自身重定向到同一页面以防止重新提交。页面重定向到自身后，标签将显示“谢谢”。问题是当我刷新页面或转到另一个页面并返回时，标签仍然显示“谢谢”而不是“”。刷新页面或更改页面时有没有办法清除 Session["Results"] 或更好的解决方案？提前致谢。

using System;
using System.Collections.Generic;
using System.Linq;
using System.Web;
using System.Web.UI;
using System.Web.UI.WebControls;
using System.IO;
using System.Net.Mail;

public partial class Contact : System.Web.UI.Page
{
    protected void Page_Load(object sender, EventArgs e)
    {
        Session["ClickedLink"] = "Contact";

        lblResults.Text = "";

        if (!IsPostBack)
        {
            lblResults.Text = Session["Results"].ToString();
        }       
    }

    protected void btnSend_Click(object sender, EventArgs e)
    {
        if (Page.IsValid)
        {
            string fileName = Server.MapPath("~/App_Data/Contact.txt");
            string mailBody = File.ReadAllText(fileName);
            mailBody = mailBody.Replace("##Name##", txtName.Text);
            mailBody = mailBody.Replace("##Email##", txtEmail.Text);
            mailBody = mailBody.Replace("##Message##", txtMessage.Text);
            MailMessage myMessage = new MailMessage();
            myMessage.Subject = "Response from web site";
            myMessage.Body = mailBody;
            myMessage.From = new MailAddress("intern2@gmail.com", "Sender Name");
            myMessage.To.Add(new MailAddress("intern2@gmail.com", "Receiver Name"));
            myMessage.ReplyToList.Add(new MailAddress(txtEmail.Text));
            SmtpClient mySmtpClient = new SmtpClient();
            mySmtpClient.Send(myMessage);

            txtName.Text = "";
            txtEmail.Text = "";
            txtMessage.Text = "";
        }

        lblResults.Text = "Thank you";
        Session["Results"] = lblResults.Text;
        Response.Redirect("Contact.aspx");

    }
}

Answer 1

另一种解决方案是在使用后添加一行清除会话变量：

protected void Page_Load(object sender, EventArgs e)
{
    Session["ClickedLink"] = "Contact";

    lblResults.Text = "";

    if (!IsPostBack)
    {
        lblResults.Text = Session["Results"].ToString();

        Session["Results"] = null;
    }       
}

在 QueryString 中，用户可以手动插入一个值以显示在标签中。

Answer 2

您可以在重定向时在查询字符串中发送消息。

protected void btnSend_Click(object sender, EventArgs e)
{
    // ...

    Response.Redirect("Contact.aspx?msg=Thanks");

}

在页面加载时

protected void Page_Load(object sender, EventArgs e)
{
    Session["ClickedLink"] = "Contact";

    lblResults.Text = "";

    if (!IsPostBack)
    {
        if (Request.QueryString["msg"] != null) 
            lblResults.Text = Request.QueryString["msg"];
    }       
}