This post originated from an RSS feed registered with .NET Buzz by Eric Gunnerson. Original Post: Splash Screens and non-rectangular windows Feed Title: Eric Gunnerson's C# Compendium Feed URL: /msdnerror.htm?aspxerrorpath=/ericgu/Rss.aspx Feed Description: Eric comments on C#, programming and dotnet in general, and the aerodynamic characteristics of the red-nosed flying squirrel of the Lesser Antilles Latest .NET Buzz Posts Latest .NET Buzz Posts by Eric Gunnerson Latest Posts From Eric Gunnerson's C# Compendium

I needed a splash screen for my music player app. I tried a couple of ideas that didn't work very well, but then I hit on the idea of using the image of a CD as the background of the splash screen - and doing a non-rectangular window. I'll start with the splash screen...

Conceptually, a splash screen is pretty simple - it's just a form that you bring up at the start of the program. The code is something like this:

SplashForm splashForm;
public MyForm()
{
    splashForm = new SplashForm();
    splashForm.Show();
}

and we'll hook the Activated event to hide the form.

When we run this, however, something strange happens. The form comes up, but it never renders - there's just a black background. This is because we need the windows messages to be processed to get the form to paint. There are several ways to do this, but my choice is to simply call Application.DoEvents() after the form is shown. This processes any messages that have yet to be processed, showing the form.

Next, we need to make a non-rectangular form. This is done by setting the region on the form. This is surprisingly easy to do. Here's the code I used for the CD:

public SplashForm()
{
    GraphicsPath p = new GraphicsPath();
    p.AddEllipse(2, 4, 340, 341);
    p.AddEllipse(150, 153, 43, 43);
    this.Region = new Region(p);

    ...
}

The first ellipse defines the outside of the picture, and then the second one this inside. This gives me a round window with a hole in the center.

Pretty cool!