Force WPF application to maximize on Windows startup

Question

I have a WPF app that installed on Windows 10 Pro via ClickOnce and uses MahApps.Metro.

It is set to launch on Windows boot with a non-admin account that has no password. Tablet mode is enabled.

I want the application pop up full screen to create kiosk-like experience, however the app starts minimized when launching on boot. To clarify, the WindowState is Maximized, but Windows does not show it, instead it shows the start screen. It launches fullscreen maximized when launching manually.

Here is some code, however I guess this is more of a configuration problem than code problem:

This is how I set the launch on boot:

RegistryKey rkApp = Registry.CurrentUser.OpenSubKey(@"SOFTWARE\Microsoft\Windows\CurrentVersion\Run", true);
string startPath = Environment.GetFolderPath(Environment.SpecialFolder.Programs)
                       + @"\Publisher\AppName.appref-ms";
rkApp.SetValue("AppName", startPath);

This is MainWindow.xaml

<Controls:MetroWindow x:Class="AppName.MainWindow"
IgnoreTaskbarOnMaximize="True" ShowTitleBar="False" WindowStyle="None" WindowState="Maximized">
...
</Controls:MetroWindow>

http://stackoverflow.com/questions/3501151/maximize-a-window-programmatically-and-prevent-the-user-from-changing-the-window — Fabrizio Stellato, Oct 12 '16 at 13:27
@FabrizioStellato The question you refer to is `WinForms`, the OP is using `WPF`. — Maarten, Oct 12 '16 at 13:39
I think perhaps this link might help, http://stackoverflow.com/questions/18721904/wpf-metro-window-full-screen — Bearcat9425, Oct 12 '16 at 13:40
The linked question does not handle issue with with Windows startup — lahjaton_j, Oct 13 '16 at 07:18

score 2 · Answer 1 · answered Oct 12 '16 at 14:19

Take a look at Kiosk Mode for Windows 10.

From Set up a device for anyone to use (kiosk mode):

A single-use device is easy to set up in Windows 10 for desktop editions (Pro, Enterprise, and Education). For a kiosk device to run a Universal Windows app, use the assigned access feature. For a kiosk device (Windows 10 Enterprise or Education) to run a Classic Windows application, use Shell Launcher to set a custom user interface as the shell.

From Assigned access (Industry 8.1):

Administrators can use assigned access to restrict a user account to access a single application. You can use assigned access to set up single-function devices, such as restaurant menus or displays at trade shows.

The following table identifies the type of application that can be used on each Windows 10 edition to create a kiosk device.

A Universal Windows app is built on the Universal Windows Platform (UWP), which was first introduced in Windows 8 as the Windows Runtime. A Classic Windows application uses the Classic Windows Platform (CWP) (e.g., COM, Win32, WPF, WinForms, etc.) and is typically launched using an .EXE or .DLL file.

I am aware of this, but thanks for the good overview for other users seeking the answer. Assigned access is not an option since I have a Classic windows app and Enterprise is not available. I hope there is a simpler way than Shell Launcher, but I might have to look into it. — lahjaton_j, Oct 13 '16 at 06:31

score 1 · Answer 2 · answered Oct 12 '16 at 13:33

1

You can do this in the MainWindow.xaml.cs by adding a windowstate of maximized.

public MainWindow()
{
    InitializeComponent();
    this.WindowState = WindowState.Maximized;
}

answered Oct 12 '16 at 13:33

Kyle Hancock

132
8

The OP already has the XAML equivalent: `WindowState="Maximized"` – Maarten Oct 12 '16 at 13:36
it should be popped on windows start up, how it can be done? – Green Falcon Oct 12 '16 at 13:37

score 1 · Accepted Answer · answered Oct 31 '16 at 08:26

1

The solution (hack) was to open any other window (e.g. powershell) on startup using Task Scheduler, and after another window is open, we can call Alt+Tab in a powershell script using.

[void] [System.Reflection.Assembly]::LoadWithPartialName("System.Windows.Forms")
[System.Windows.Forms.SendKeys]::SendWait("%{TAB}")

answered Oct 31 '16 at 08:26

lahjaton_j

805
7
13

Still amazed by this solution years after. Thanks Microsoft. – lahjaton_j Aug 14 '19 at 13:21

E-Bat · Answer 4 · 2016-10-17T20:41:07.880

0

Set the Window state in the ContentRendered event handler:

protected override void OnStartup(StartupEventArgs e)
{  
    Application.Current.MainWindow.ContentRendered += (s, a) => 
        Application.Current.MainWindow.WindowState = WindowState.Maximized;

}

edited Oct 17 '16 at 20:41

answered Oct 12 '16 at 15:44

E-Bat

4,792
1
33
58

The problem is that WindowState already is Maximized, but Windows somehow decides not to view the program. Perhaps they disabled this on pupose. – lahjaton_j Oct 13 '16 at 06:50
So the issue is not about maximizing but instead your main window is hidden? – E-Bat Oct 13 '16 at 14:06
On startup, Windows shows only the start screen, even if the windowstate is maximized. On other occasions it works just fine. – lahjaton_j Oct 14 '16 at 05:25

Force WPF application to maximize on Windows startup

4 Answers4