Initial commit

Helper/Messagebox.cs

@@ -0,0 +1,63 @@
+using System;
+using System.Data;
+using System.Configuration;
+using System.Web;
+using System.Web.Security;
+using System.Web.UI;
+using System.Web.UI.WebControls;
+using System.Web.UI.WebControls.WebParts;
+using System.Web.UI.HtmlControls;
+using System.Collections;
+using System.Collections.Generic;
+
+namespace QW2021C.Helper
+{
+    public class MessageBox
+    {
+        // Lets keep the message coming from all the pages here
+        static Dictionary<Page, Queue> pageTable = null;
+
+        static MessageBox()
+        {
+            // Create the store
+            pageTable = new Dictionary<Page, Queue>();
+        }
+
+        public static void Show(string str)
+        {
+            // Lets find out what page is sending the request
+            Page page = HttpContext.Current.Handler as Page;
+
+            // If a valid page is found
+            if (page != null)
+            {
+                // Check if this page is requesing message show for the first time
+                if (pageTable.ContainsKey(page) == false)
+                {
+                    // Lets create a message queue dedicated for this page.
+                    pageTable.Add(page, new Queue());
+                }
+
+                // Let us add messages of this to the queue now
+                pageTable[page].Enqueue(str);
+
+                // Now let put a hook on the page unload where we will show our message
+                page.Unload += new EventHandler(page_Unload);
+            }
+        }
+
+        static void page_Unload(object sender, EventArgs e)
+        {
+            // Lets find out which page is getting unloaded
+            Page page = sender as Page;
+
+            // If a valid page is founf
+            if (page != null)
+            {
+                // Extract the messages for this page and push them to client side
+                HttpContext.Current.Response.Write("<script>alert('" + pageTable[page].Dequeue() + "');</script>");
+            }
+        }
+    }
+
+}