如何在 response.redirect(request.rawurl) 之前显示我的文本标签

Question

我正在尝试在之前显示我的 status_lbl 文本标签

Response.Redirect(Request.RawUrl);

我尝试在重定向页面功能之前设置延迟时间，但它仍然没有显示 status_lbl 文本标签。

using System;
using System.Collections.Generic;
using System.Linq;
using System.Web;
using System.Web.UI;
using System.Web.UI.WebControls;
using System.Data;
using System.Data.SqlClient;
using System.Configuration;
using System.Web.Services;
using System.Web.Script;
using System.Web.Security;

namespace TagNumberWeb
{
public partial class Main : System.Web.UI.Page
{
    protected void Page_Load(object sender, EventArgs e)
    {
        string CrUserID = Request.QueryString["LogInUser"].ToString();
        string Result = Request.QueryString["Result"].ToString();

        if (!IsPostBack)
        {
            if (string.IsNullOrWhiteSpace(CrUserID) || string.IsNullOrWhiteSpace(Result))
            {
                Response.Redirect("Login Page.aspx");
            }

            else
            {                    
                UserID.Text = Request.QueryString["LogInUser"].ToString();
                status_lbl.Visible = false;
                GridView1.Visible = false;
            }
        }
    }

    protected void Button1_Click(object sender, EventArgs e)
    {
        string sONbr = sONbrTextBox.Text;
        string SOLine = sOLineTextBox.Text;
        string SerialNbr = serialNbrTextBox.Text;
        string StatusCode = statusCodeComboBox.Text;
        string CrUserID = Request.QueryString["LogInUser"].ToString();

        if (string.IsNullOrWhiteSpace(sONbr) || string.IsNullOrWhiteSpace(SOLine) || string.IsNullOrWhiteSpace(StatusCode) || string.IsNullOrEmpty(SerialNbr))
        {
            status_lbl.Text = "Please fill in all the information.";
            status_lbl.Visible = true;
            GridView1.Visible = false;
            return;
        }

        else if (string.IsNullOrWhiteSpace(CrUserID))
        {
            status_lbl.Text = "Please login your account!";
            status_lbl.Visible = true;
            ClientScript.RegisterStartupScript(Page.GetType(), "validation", "<script language='javascript'>alert('Please login your account!')</script>");
            Response.Redirect("Login Page.aspx");
            GridView1.Visible = false;
            return;
        }

        else if (CheckBox1.Checked == true)
        {

            SqlConnection conn = new SqlConnection(ConfigurationManager.ConnectionStrings["constr_BCSystem"].ToString());
            conn.Open();

            SqlCommand comm = conn.CreateCommand();
            comm.CommandType = CommandType.StoredProcedure;
            comm.CommandText = "usp_TagNumberUpdate";

            comm.Parameters.AddWithValue("@sONbr", sONbr);
            comm.Parameters.AddWithValue("@SOLine", SOLine);
            comm.Parameters.AddWithValue("@SerialNbr", SerialNbr);
            comm.Parameters.AddWithValue("@StatusCode", StatusCode);
            comm.Parameters.AddWithValue("@CrUserID", CrUserID);

            SqlParameter ReturnVal = comm.Parameters.Add("@return", SqlDbType.NVarChar, 200);
            ReturnVal.Direction = ParameterDirection.Output;

            comm.ExecuteNonQuery();

            string val = (string)ReturnVal.Value;

            conn.Close();
            status_lbl.Text = val;
            status_lbl.Visible = true;
            Response.Redirect(Request.RawUrl);

        }

        else 
        {
            SqlConnection conn = new SqlConnection(ConfigurationManager.ConnectionStrings["constr_BCSystem"].ToString());
            conn.Open();

            SqlCommand comm = conn.CreateCommand();
            comm.CommandType = CommandType.StoredProcedure;
            comm.CommandText = "usp_TagNumberUpdateNoSN";

            comm.Parameters.AddWithValue("@sONbr", sONbr);
            comm.Parameters.AddWithValue("@SOLine", SOLine);
            comm.Parameters.AddWithValue("@StatusCode", StatusCode);
            comm.Parameters.AddWithValue("@CrUserID", CrUserID);

            SqlParameter ReturnVal = comm.Parameters.Add("@return", SqlDbType.NVarChar, 200);
            ReturnVal.Direction = ParameterDirection.Output;

            comm.ExecuteNonQuery();

            string val = (string)ReturnVal.Value;

            conn.Close();
            status_lbl.Text = val;
            status_lbl.Visible = true;
            Response.Redirect(Request.RawUrl);
        }
    }

Answer 1

这是因为，当您重定向到同一页面时，上下文会丢失。

Page_Load  

事件再次被执行。

你应该像下面这样改变你的代码。

将您的 Button1_Click 更改为：

protected void Button1_Click(object sender, EventArgs e)
    {
        string sONbr = sONbrTextBox.Text;
        string SOLine = sOLineTextBox.Text;
        string SerialNbr = serialNbrTextBox.Text;
        string StatusCode = statusCodeComboBox.Text;
        string CrUserID = Request.QueryString["LogInUser"].ToString();

        if (string.IsNullOrWhiteSpace(sONbr) || string.IsNullOrWhiteSpace(SOLine) || string.IsNullOrWhiteSpace(StatusCode) || string.IsNullOrEmpty(SerialNbr))
        {
            status_lbl.Text = "Please fill in all the information.";
            status_lbl.Visible = true;
            GridView1.Visible = false;
            return;
        }

        else if (string.IsNullOrWhiteSpace(CrUserID))
        {
            status_lbl.Text = "Please login your account!";
            status_lbl.Visible = true;
            ClientScript.RegisterStartupScript(Page.GetType(), "validation", "<script language='javascript'>alert('Please login your account!')</script>");
            Response.Redirect("Login Page.aspx");
            GridView1.Visible = false;
            return;
        }

        else if (CheckBox1.Checked == true)
        {

            SqlConnection conn = new SqlConnection(ConfigurationManager.ConnectionStrings["constr_BCSystem"].ToString());
            conn.Open();

            SqlCommand comm = conn.CreateCommand();
            comm.CommandType = CommandType.StoredProcedure;
            comm.CommandText = "usp_TagNumberUpdate";

            comm.Parameters.AddWithValue("@sONbr", sONbr);
            comm.Parameters.AddWithValue("@SOLine", SOLine);
            comm.Parameters.AddWithValue("@SerialNbr", SerialNbr);
            comm.Parameters.AddWithValue("@StatusCode", StatusCode);
            comm.Parameters.AddWithValue("@CrUserID", CrUserID);

            SqlParameter ReturnVal = comm.Parameters.Add("@return", SqlDbType.NVarChar, 200);
            ReturnVal.Direction = ParameterDirection.Output;

            comm.ExecuteNonQuery();

            string val = (string)ReturnVal.Value;

            conn.Close();
            Response.Redirect(Request.RawUrl+"?status="+val);

        }

        else 
        {
            SqlConnection conn = new SqlConnection(ConfigurationManager.ConnectionStrings["constr_BCSystem"].ToString());
            conn.Open();

            SqlCommand comm = conn.CreateCommand();
            comm.CommandType = CommandType.StoredProcedure;
            comm.CommandText = "usp_TagNumberUpdateNoSN";

            comm.Parameters.AddWithValue("@sONbr", sONbr);
            comm.Parameters.AddWithValue("@SOLine", SOLine);
            comm.Parameters.AddWithValue("@StatusCode", StatusCode);
            comm.Parameters.AddWithValue("@CrUserID", CrUserID);

            SqlParameter ReturnVal = comm.Parameters.Add("@return", SqlDbType.NVarChar, 200);
            ReturnVal.Direction = ParameterDirection.Output;

            comm.ExecuteNonQuery();

            string val = (string)ReturnVal.Value;

            conn.Close();
            Response.Redirect(Request.RawUrl+"?status="+val);
        }
    }

你的Page_Load 应该是：

protected void Page_Load(object sender, EventArgs e)
    {
        string CrUserID = Request.QueryString["LogInUser"].ToString();
        string Result = Request.QueryString["Result"].ToString();
        if(Request.RawUrl.Contains("?status"))
        {
           string val=Request["status"];
           status_lbl.Text = val;   
           status_lbl.Visible = true;
        }
        if (!IsPostBack)
        {
            if (string.IsNullOrWhiteSpace(CrUserID) || string.IsNullOrWhiteSpace(Result))
            {
                Response.Redirect("Login Page.aspx");
            }

            else
            {                    
                UserID.Text = Request.QueryString["LogInUser"].ToString();
                status_lbl.Visible = false;
                GridView1.Visible = false;
            }
        }
    }