How do I close the on-screen keyboard process from C# winform correctly?

Question

I'm currently designing an image viewer that allows the user to input her e-mail and get the images digitally. The part that troubles me is getting the on-screen keyboard to close. I use this piece of code to start the windows process:

string progFiles = @"C:\Program Files\Common Files\Microsoft Shared\ink";
string keyboardPath = Path.Combine(progFiles, "TabTip.exe");
Process keyboardProc = Process.Start(keyboardPath);

After which i open a VB InputBox to prompt for the e-mail address (for which i use the on-screen keyboard, since the application will be shown on a touch screen). After this prompt I want to close the process automatically.

I've tried to close the process with the following:

keyboardProc.Kill();
keyboardProc.Dispose();
keyboardProc.Close();
keyboardProc = null;

None of them works and simply throws the exception:

An unhandled exception of type 'System.InvalidOperationException' occurred in System.dll
Additional information: Cannot process request because the process has exited.

I also tried identifying the process by ID and closing it this way, didn't work either. I also had a look at: C#/.NET: Closing another process outside the main window but didn't get it working either.. :(

I'm pretty new to C# and this is the first time I've invoked a windows process from code - am I missing something?

Thank you very much in advance!

`.Kill()` works for me. Are you sure you only kill it once and there's nothing else you are doing that might cause the exception? — pascalhein, May 30 '13 at 09:27
`keyboardProc.CloseMainWindow()` [(MSDN)](http://msdn.microsoft.com/en-us/library/system.diagnostics.process.closemainwindow.aspx?cs-save-lang=1&cs-lang=csharp#code-snippet-1) should do the trick. — John Willemse, May 30 '13 at 09:45
Thank you for your comments, tried the .Kill(), .CloseMainWindow() - both throw an exception because the process already exited :s Will try with hiding now — Cassini, May 30 '13 at 10:55
@csharpler I don't know what could cause the exception.. All I do is start the process, open an InputBox and prompt for input, then I want to close/kill the process — Cassini, May 30 '13 at 11:07
Solved this by faking a mouse-click with a virtual mouse.. sketchy, but it did the job. [Here is the code](http://www.sourcepod.com/asczzd16-18920) — Cassini, May 30 '13 at 11:55

score 5 · Answer 1 · answered Aug 05 '14 at 09:28

    /// <summary>
    /// Show the On Screen Keyboard
    /// </summary>
    #region ShowOSK
    public static void ShowOnScreenKeyboard()
    {
        ProcessStartInfo startInfo = new ProcessStartInfo(@"C:\Program Files\Common Files\Microsoft Shared\ink\TabTip.exe");
        Process.Start(startInfo);
    }
    #endregion ShowOSK

    /// <summary>
    /// Hide the On Screen Keyboard
    /// </summary>
    #region HideOSK
    public static void HideOnScreenKeyboard()
    {
        uint WM_SYSCOMMAND = 274;
        uint SC_CLOSE = 61536;
        IntPtr KeyboardWnd = FindWindow("IPTip_Main_Window", null);
        PostMessage(KeyboardWnd.ToInt32(), WM_SYSCOMMAND, (int)SC_CLOSE, 0);
    }
    #endregion HideOSK

M Safwan · Answer 2 · 2020-09-06T01:11:31.533

The following code will open & close Touch Keyboard on Window 10 the quickest, compared to executing / closing TabTip.exe directly. (tested on low power tablet).

    [return: MarshalAs(UnmanagedType.Bool)]
    [DllImport("user32.dll", SetLastError = true)]
    static extern bool PostMessage(IntPtr hWnd, uint Msg, UIntPtr wParam, IntPtr lParam);

    [DllImport("user32.dll", CharSet = CharSet.Unicode)]
    static extern IntPtr FindWindow(String sClassName, String sAppName);

    [DllImport("user32.dll", CharSet = CharSet.Unicode)]
    static extern IntPtr FindWindowEx(IntPtr hwndParent, IntPtr hwndChildAfter, String lpszClass, String lpszWindow);

    /// <summary>
    /// Show the On Screen Keyboard
    /// </summary>
    #region ShowOSK
    public static void ShowOnScreenKeyboard()
    {
        IntPtr parent = FindWindow("Shell_TrayWnd", null);
        IntPtr child1 = FindWindowEx(parent, IntPtr.Zero, "TrayNotifyWnd", "");
        IntPtr keyboardWnd = FindWindowEx(child1, IntPtr.Zero, "TIPBand", "Touch keyboard");

        uint WM_LBUTTONDOWN = 0x0201;
        uint WM_LBUTTONUP = 0x0202;
        UIntPtr x = new UIntPtr(0x01);
        UIntPtr x1 = new UIntPtr(0x0);
        IntPtr y = new IntPtr(0x0100020);
        PostMessage(keyboardWnd, WM_LBUTTONDOWN, x, y);
        PostMessage(keyboardWnd, WM_LBUTTONUP, x1, y);
    }
    #endregion ShowOSK

    /// <summary>
    /// Hide the On Screen Keyboard
    /// </summary>
    #region HideOSK
    public static void HideOnScreenKeyboard()
    {
        uint WM_SYSCOMMAND = 0x0112;
        UIntPtr SC_CLOSE = new UIntPtr(0xF060);
        IntPtr y = new IntPtr(0);
        IntPtr KeyboardWnd = FindWindow("IPTip_Main_Window", null);
        PostMessage(KeyboardWnd, WM_SYSCOMMAND, SC_CLOSE, y);
    }
    #endregion HideOSK

It worked for me partially. It hides keyboard but it doesn't show. — Jordi Espada, Jun 16 '20 at 16:26
now it works. If not, or no longer work in future, then check the new name with Spy++ (VisualStudio>Tools>Spy++ which came with C++ package). Class name is "TIPBand", Caption is "Touch keyboard", and the x, x1 and y parameters can be read using the Message window. — M Safwan, Sep 06 '20 at 01:23

score 2 · Answer 3 · answered Jul 31 '13 at 09:17

I had trouble with this too. For some reason this works, although it kills all open TabTip processes.

            //Kill all on screen keyboards
            Process[] oskProcessArray = Process.GetProcessesByName("TabTip");
            foreach (Process onscreenProcess in oskProcessArray)
            {
                onscreenProcess.Kill();
            }

score 1 · Accepted Answer · answered May 30 '13 at 11:30

1

u can do:

            Process process = new Process();

            process.StartInfo.FileName = progFiles;//Filename
            process.Start();
            process.Close();

answered May 30 '13 at 11:30

praks

118
1
7

Tried that :/ Thank you for replying! – Cassini May 30 '13 at 11:54
can u add ur code ? what u have mention above in u r question it should works or u are doing some different – praks May 30 '13 at 12:43
Hey, yea I changed my code to solve this issue. You can see what I did here: `http://www.sourcepod.com/asczzd16-18920` – Cassini May 30 '13 at 12:52

How do I close the on-screen keyboard process from C# winform correctly?

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