How to center a WPF app on screen?

I want to center my WPF app on startup on the primary screen. I know I have to set myWindow.Left and myWindow.Top, but where do I get the values?

I found System.Windows.Forms.Screen.PrimaryScreen, which is apparently not WPF. Is there a WPF alternative that gives me the screen resolution or something like that?

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You can still use the Screen class from a WPF app. You just need to reference the System.Windows.Forms assembly from your application. Once you've done that, (and referenced System.Drawing for the example below):

Rectangle workingArea = System.Windows.Forms.Screen.PrimaryScreen.WorkingArea;

...works just fine.

Have you considered setting your main window property WindowStartupLocation to CenterScreen?

There is no WPF equivalent. System.Windows.Forms.Screen is still part of the .NET framework and can be used from WPF though.

See this question for more details, but you can use the calls relating to screens by using the WindowInteropHelper class to wrap your WPF control.

What about the SystemParameters class in PresentationFramework? It has a WorkArea property that seems to be what you are looking for.

But, why won't setting the Window.WindowStartupLocation work? CenterScreen is one of the enum values. Do you have to tweak the centering?

Put this in your window constructor

WindowStartupLocation = System.Windows.WindowStartupLocation.CenterScreen;

.NET FrameworkSupported in: 4, 3.5, 3.0

.NET Framework Client ProfileSupported in: 4, 3.5 SP1

xaml

<Window ... WindowStartupLocation="CenterScreen">...

You don't need to reference the System.Windows.Forms assembly from your application. Instead, you can use System.Windows.SystemParameters.WorkArea. This is equivalent to the System.Windows.Forms.Screen.PrimaryScreen.WorkingArea!

var window = new MyWindow();

for center of the screen use:

window.WindowStartupLocation = System.Windows.WindowStartupLocation.CenterScreen;

for center of the parent window use:

window.WindowStartupLocation = System.Windows.WindowStartupLocation.CenterOwner;

I prefer to put it in the WPF code.

In [WindowName].xaml file:

<Window x:Class=...
...
WindowStartupLocation ="CenterScreen">