With the new UI model within SharePoint, there is a lot (LOTS) you can do from within JavaScript. 

As well as the client object model to get list & web details from SharePoint (from client side !) – you can also add a cool UI notification – like the ‘loading’ one shown here :

This uses the SP.UI.Notify.addNotification method – click the link to see some good examples at the MSDN site.

This is all great – but for SERVER side code – after a postback – from within C# – how do you do it ?!

Well, there is a way – in which you build up the JavaScript for the ‘addNotification’ – and then add the text/string to the Page output – and then it executes !  

The following C# method does the following :

• Input parameter – of the current PAGE object – either inside a webpart, or ASCX control, for example
• Input parameter – TEXT for the notification to display
• Build up a JavaScript “SCRIPT” block – for the code to execute
• IMPORTANT (this is the gotcha) – need to ‘delay until script loaded’ for the SP.JS file – otherwise, you get a NULL reference exception – ExecuteOrDelayUntilScriptLoaded
• Add the JS to call to the actual method for the notification : SP.UI.Notify.addNotification
• Create a new ASP.NET literal control – which adds the ‘raw text’ to the page
• The notification is then shown, after the page refreshes – NICE !!

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public static void AddSharePointNotification(Page page, string text)
{
    //build up javascript to inject at the tail end of the page
    StringBuilder stringBuilder = new StringBuilder();

    stringBuilder.AppendLine("<script>");

    //First wait until the SP.js is loaded, otherwise the notification doesn’t work
    //gets an null reference exception
    stringBuilder.AppendLine("ExecuteOrDelayUntilScriptLoaded(ShowNotification, "sp.js");");

    stringBuilder.AppendLine("function ShowNotification()");
    stringBuilder.AppendLine("{");
    stringBuilder.AppendLine(string.Format("SP.UI.Notify.addNotification("{0}");", text));
    stringBuilder.AppendLine("}");

    stringBuilder.AppendLine("</script>");

    //add to the page
    page.Controls.Add(new LiteralControl(stringBuilder.ToString()));

}

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I’m sure this could be edited to do the SP.UI.Status.addStatus method also/instead.

Hope that’s helpful to you…!

** I’m planning to use this as a way of notifying the user of an EXCEPTION – within the end of a try-catch.