How to open the tablet-mode on-screen-keyboard in C#?

Question

I want to start the new On-Screen-Keyboard (OSK) using code. You can find this one in the taskbar:

(if not there you find it by right clicking the taskbar).

I have already tried the regular:

System.Diagnostics.Process.Start("osk.exe");

But I want to start the other one (not in window mode). Here you see which OSK I want and which one not:

How can I start that version? And how can I start it in a certain setting (if possible)?

Answer 1

By starting a process in command-line

I believe you want to start the following process in Windows 10, as suggested here :

"C:\Program Files\Common Files\microsoft shared\ink\tabtip.exe"

As suggested by @bernard-vander-beken, it's better to use

Environment.GetFolderPath(Environment.SpecialFolder.CommonProgramFiles)

to produce the "C:\Program Files\Common Files\" part of the path to fit different install locations.

Through an API

The previous command-line seems to work in inconsistent ways, in particular it doesn't work twice if the tabtip.exe process is already running.

I found this snippet by @torvin on this thread , which you can use to programmatically show the on-screen keyboard after you've started the tabtip.exe using the command-line solution, otherwise it fails with a COM exception.

class Program
{
    static void Main(string[] args)
    {
        var uiHostNoLaunch = new UIHostNoLaunch();
        var tipInvocation = (ITipInvocation)uiHostNoLaunch;
        tipInvocation.Toggle(GetDesktopWindow());
        Marshal.ReleaseComObject(uiHostNoLaunch);
    }

    [ComImport, Guid("4ce576fa-83dc-4F88-951c-9d0782b4e376")]
    class UIHostNoLaunch
    {
    }

    [ComImport, Guid("37c994e7-432b-4834-a2f7-dce1f13b834b")]
    [InterfaceType(ComInterfaceType.InterfaceIsIUnknown)]
    interface ITipInvocation
    {
        void Toggle(IntPtr hwnd);
    }

    [DllImport("user32.dll", SetLastError = false)]
    static extern IntPtr GetDesktopWindow();
}