在WPF App.xaml.cs文件中更改Main方法

Question

Currently i changed my Main method in my WPF project like that:

public static void Main() 
{
    // Call Log4net configuration to configure all Appenders
    log4net.Config.XmlConfigurator.Configure();
    // Check if Application is already running, if it is running - Kill
    if (System.Diagnostics.Process.GetProcessesByName(System.IO.Path.GetFileNameWithoutExtension(System.Reflection.Assembly.GetEntryAssembly().Location)).Length > 1) System.Diagnostics.Process.GetCurrentProcess().Kill();

    Controller.App app = new Controller.App();        
    app.InitializeComponent();
    app.Run();
}

I added a method call to configure my Log4Net framework and i check if an instance of my application is running already.

Previously i had this methods in my MainWindow.CS file -> MainWindow constructor.

Now im curious if it is common/good practice to do verifications like this two method calls in the Main method of the application or if it should be done in the MainWindow.CS as i did before. Are there any concerns to do this in the Main method. so far everything works fine in my application.

Answer 1

Yes this is perfectly valid and I've seen this more than once.

Setting up your logging infrastructure in the main allows you to log any issue that could occur when running the application, eg if you have an error in your App.xaml .

Moreover you avoid launching the WPF application for nothing if you must close it immediately, though in the general case should not be an issue.

As for the way you detect if your application is already running and stop it, well this is quite "original". :) The standard way of doing this is by using a global system mutex and if present then jumping to the end of the Main .

Answer 2

I've found that rather than messing with the underlying internals of a WPF Application by changing Main() it's better to rather override the OnStartup() method in the App.xaml.cs .

I call log4net's Configure() there and perform a number of other application specific configuration operations there before allowing the main window to be shown.

I've found that this avoids issues with the underlying wiring that makes up a WPF application and leads to less issues in the long run.