What code controls the startup of a WPF application?

Question

More specifically, how could I setup a startup sequence like this one in WPF where no window is shown at start, but a notification icon is present?

Answer 1

To run, WPF requires an Application object. when you execute Run on that object, the application goes into an infinite loop: the event loop responsible for handling user input and any other OS signals.

In other words, you can include a custom Main function in a WPF app just fine; it merely needs to look something like this:

[STAThread]
public static void Main(string[] args) {
    //include custom startup code here

    var app = new MyApplication();//Application or a subclass thereof
    var win = new MyWindow();//Window or a subclass thereof
    app.Run(win); //do WPF init and start windows message pump.
}

Here's an article about some of the gotcha's using this approach: The Wpf Application class: Overview and Gotcha. In particular, you'll probably want to set things like Application.ShutdownMode. This approach leaves you free to do whatever you want before any WPF code runs - but, more importantly, I hope it elucidates how WPF apps start.