Can I display the onscreen keyboard of a Windows 8 tablet from Unity?

Questions & Answers
1

Which is part of my bigger question right now: Is trying to get a touch-based iOS/Android game working on Windows 8 tablets right now with Unity 4.2 a lost cause, or merely an uphill battle?

4

if its a windows app you can easily do it like this

using System;
using System.Runtime.InteropServices;

public static class KeyboardInterop
{

    [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, null, "Touch keyboard");

        uint WM_LBUTTONDOWN = 0x0201;
        uint WM_LBUTTONUP = 0x0202;
        UIntPtr x = new UIntPtr(0x01);
        UIntPtr x1 = new UIntPtr(0);
        IntPtr y = new IntPtr(0x0240012);
        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

}
2

Currently, no.

http://forum.unity3d.com/threads/186697-No-Keyboard-on-Windows-8

3

You can do it with a script. Use the keybord of windows store like this example Browse code samples | Microsoft Learn
Use comunication betwean unity and windows store apps