How to detect that C# Windows Forms code is executed within Visual Studio?

Question

Is there a variable or a preprocessor constant that allows to know that the code is executed within the context of Visual Studio?

Answer 1

I use this extension method:

internal static class ControlExtension
{
    public static bool IsInDesignMode(this Control control)
    {
        while (control != null)
        {
            if (control.Site != null && control.Site.DesignMode)
                return true;
            control = control.Parent;
        }
        return false;
    }
}