WPF MainWindow Override OnStartup

Question

I can't get my MainWindow to show without using StartupUri. OnStartup doesn't trigger.

I removed StartupUri from App.xaml

<Application x:Class="SCon"
         xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
         xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml">
</Application>

added the following in the code behind

    protected override void OnStartup(StartupEventArgs e)
    {
        base.OnStartup(e);
        SCon.MainWindow.Instance.Show();
    }

MainWindow is a singleton

    private static volatile MainWindow instance = null;
    private static object lockThis = new object();
    public static MainWindow Instance
    {
        get
        {
            if (instance == null)
            {
                lock (lockThis)
                {
                    if (instance == null)
                    {
                        instance = new MainWindow();
                    }
                }
            }
            return instance;
        }
    }

There has to be something that's specified as a start up window. Do you mean you want 2 windows to show up automatically when your application starts? — Rod, Feb 11 '14 at 20:30
No it's only the MainWindow turned into a singleton. So I try to override OnStartup to create my window but it never triggers OnStartup — Tsukasa, Feb 11 '14 at 20:32

score 2 · Accepted Answer · edited May 23 '17 at 12:17

2

Idk what you mean or where you stuck at. I would check Build Actions of App.xaml then I would take a look to this site.

http://www.erikojebo.se/Code/Details/202

That guy explains is pretty well :)

Also your question is sort of a duplicate. Check this out: How to change StartupUri of WPF Application?

edited May 23 '17 at 12:17

Community

1
1

answered Feb 11 '14 at 20:16

dev hedgehog

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ApplicationDefinition – Tsukasa Feb 11 '14 at 20:33
Remove base.OnStartup(e); – dev hedgehog Feb 11 '14 at 20:37
Same it never enters OnStartup – Tsukasa Feb 11 '14 at 20:39
1

Ahhhhhhhhhh your X:Class is not assigned right. Try this x:Class="Namespace.Class" – dev hedgehog Feb 11 '14 at 20:41
OH Thank you. I changed namespace names and never corrected it here. Thanks it's working as it should now. – Tsukasa Feb 11 '14 at 20:53

score 1 · Answer 2 · answered May 19 '15 at 10:14

You need to put the following line in the XAML file:

<Application x:Class="SCon"
         xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
         xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
         Startup="OnStartup">
</Application>

That's why it didn't trigger the OnStartup method.

WPF MainWindow Override OnStartup

2 Answers2