Server Side Javascript Alert in C#

Question

I'm attempting to create an alert that works on the server side, preferably using JavaScript. This alert is displayed if a user's input does not match a value pulled from a SQL server. The client side alert I was using was:

MessageBox.Show("User Input was not found. Please try again.", "Error", MessageBoxButtons.OK, MessageBoxIcon.Asterisk);

I attempted to replicate this by doing:

   string message = "User Input was not found. Please try again.";
   System.Text.StringBuilder sb = new System.Text.StringBuilder();
   sb.Append("<script type = 'text/javascript' runat = 'server'>");
   sb.Append("window.onload=function(){");
   sb.Append("alert('");
   sb.Append(message);
   sb.Append("')};");
   sb.Append("</script>");
   Page.ClientScript.RegisterClientScriptBlock(this.GetType(), "alert", sb.ToString());

I also tried this:

   ClientScriptManager cs = Page.ClientScript;
   cs.RegisterClientScriptBlock(
   this.GetType(),
   " ",
   @"<script language=javascript>alert('User Input was not found. Please try again');</script>",
   true
   );

After this alert is displayed, I'd like to immediately redirect using Respone.Redirect("redirectpage.aspx") .

Is there a more effective solution to this issue? Am I missing something from my code? This is my first time using JavaScript for server side applications, so any detail would be appreciated.

Answer 1

Try using this method, it also has parameter to Redirect to Particular page

public class HTMLHelper
    {
        public static void jsAlertAndRedirect(System.Web.UI.Page instance, string Message, string Redirect_URL)
        {
            instance.Response.Write(@"<script language='javascript'>alert('" + Message + "');document.location.href='" + url + "'; </script>");
        }
    }

Call it using this,

HTMLHelper.jsAlertAndRedirect(this.Page, "Success Message !", ResolveUrl("~/default.aspx"));

Answer 2

Use ajax

$.ajax({
  url: validationUrl,
  data: {paramName: paramValue }
}).done(function(data ) {
  if (data.error)
    alert("error");
});