How to show, close, move, or resize the on-screen keyboard in Java, C#, C++, Visual Basic, Delphi, etc.

You can use Windows Messages to control the virtual keyboard.

Example:
WM_CSKEYBOARD = WM_USER + 192;
WM_CSKEYBOARDMOVE = WM_USER + 193;
WM_CSKEYBOARDRESIZE = WM_USER + 197;

// to show keyboard
PostMessage(FindWindow('TFirstForm', 'hvkFirstForm'), WM_CSKEYBOARD, 1, 0);

// to close keyboard
PostMessage(FindWindow('TFirstForm', 'hvkFirstForm'), WM_CSKEYBOARD, 2, 0);

// to fade keyboard
PostMessage(FindWindow('TFirstForm', 'hvkFirstForm'), WM_CSKEYBOARD, 3, 0);

// to toggle (show/hide) keyboard
PostMessage(FindWindow('TFirstForm', 'hvkFirstForm'), WM_CSKEYBOARD, 4, 0);

// to move keyboard (Left, Top - new position)
PostMessage(FindWindow('TFirstForm', 'hvkFirstForm'), WM_CSKEYBOARDMOVE, Left, Top);

// to resize keyboard
PostMessage(FindWindow('TFirstForm', 'hvkFirstForm'), WM_CSKEYBOARDRESIZE, Width, Height);
Visual Basic 2008 (VB.NET) Sample Code:
Const WM_CSKEYBOARD = &H400 + 192
Const WM_CSKEYBOARDMOVE = &H400 + 193
Const WM_CSKEYBOARDRESIZE = &H400 + 197
 
Declare Function FindWindow Lib "user32" Alias "FindWindowA" (ByVal lpClassName As String, ByVal lpWindowName As String) As Integer
Declare Function PostMessage Lib "user32" Alias "PostMessageA" (ByVal hwnd As Integer, ByVal wMsg As Integer, ByVal wParam As Integer, ByVal lParam As Integer) As Integer
 
    'Open/show Hot Virtual Keyboard in Visual Basic
    Private Sub Button1_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Button1.Click
        Dim hWnd As Integer
        hWnd = FindWindow("TFirstForm", "hvkFirstForm")
        PostMessage(hWnd, WM_CSKEYBOARD, 1, 0)
    End Sub
 
    'Close Hot Virtual Keyboard in Visual Basic
    Private Sub Button2_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Button2.Click
        Dim hWnd As Integer
        hWnd = FindWindow("TFirstForm", "hvkFirstForm")
        PostMessage(hWnd, WM_CSKEYBOARD, 2, 0)
    End Sub
 
    'Move Hot Virtual Keyboard in Visual Basic; Move it first then show it
    Private Sub Button3_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Button3.Click
        Dim hWnd As Integer
        hWnd = FindWindow("TFirstForm", "hvkFirstForm")
        PostMessage(hWnd, WM_CSKEYBOARDMOVE, 200, 200)
        PostMessage(hWnd, WM_CSKEYBOARD, 1, 0)
    End Sub
 
    'Toggle Hot Virtual Keyboard in Visual Basic
    Private Sub Button4_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Button4.Click
        Dim hWnd As Integer
        hWnd = FindWindow("TFirstForm", "hvkFirstForm")
        PostMessage(hWnd, WM_CSKEYBOARD, 4, 0)
    End Sub
 
    'Fade Hot Virtual Keyboard in Visual Basic
    Private Sub Button5_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Button5.Click
        Dim hWnd As Integer
        hWnd = FindWindow("TFirstForm", "hvkFirstForm")
        PostMessage(hWnd, WM_CSKEYBOARD, 3, 0)
    End Sub
 
    'Change the keyboard type and show it
    Private Sub Button6_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Button6.Click
        'Change the Registry entry for the required keyboard
        My.Computer.Registry.SetValue("HKEY_CURRENT_USER\Software\ComfortSoftware\hvk", "KeyboardName", "Name of your chosen keyboard")
        'Open the keyboard
        Dim hWnd As Integer
        hWnd = FindWindow("TFirstForm", "hvkFirstForm")
        PostMessage(hWnd, WM_CSKEYBOARD, 1, 0)
    End Sub
 
    'Change to another keyboard type and show it
    Private Sub Button7_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Button7.Click
        'Change the Registry entry for the required keyboard
        My.Computer.Registry.SetValue("HKEY_CURRENT_USER\Software\ComfortSoftware\hvk", "KeyboardName", "Name of another chosen keyboard")
        'Open the keyboard
        Dim hWnd As Integer
        hWnd = FindWindow("TFirstForm", "hvkFirstForm")
        PostMessage(hWnd, WM_CSKEYBOARD, 1, 0)
    End Sub
C# Sample Code:
using System;
using System.Windows.Forms;
using System.Runtime.InteropServices;

public const Int32 WM_USER = 1024;
public const Int32 WM_CSKEYBOARD = WM_USER + 192;
public const Int32 WM_CSKEYBOARDMOVE = WM_USER + 193;
public const Int32 WM_CSKEYBOARDRESIZE = WM_USER + 197;

[DllImport("user32.dll", EntryPoint = "FindWindow")]
private static extern Int32 FindWindow(string _ClassName, string _WindowName);

[DllImport("User32.DLL")]
public static extern Boolean PostMessage(Int32 hWnd, Int32 Msg, Int32 wParam, Int32 lParam);


Int32 hWnd = FindWindow("TFirstForm", "hvkFirstForm");
PostMessage(hWnd, WM_CSKEYBOARD, 1, 0 ); // Show
PostMessage(hWnd, WM_CSKEYBOARD, 2, 0); // Hide
PostMessage(hWnd, WM_CSKEYBOARDMOVE, 0, 0); // Move to 0, 0
PostMessage(hWnd, WM_CSKEYBOARDRESIZE, 600, 300); // Resize to 600, 300
C++ (CLR syntax) Sample Code:
using namespace System::Runtime::InteropServices; 
using namespace System::Security::Permissions; 
using namespace Microsoft::Win32; 
 
const System::UInt32 WM_USER = 1024; 
const System::UInt32 WM_CSKEYBOARD = WM_USER + 192; 
const System::UInt32 WM_CSKEYBOARDMOVE = WM_USER + 193;  
 
[DllImport("user32.dll")] 
extern IntPtr FindWindow(String^ lpClassName, String^ lpWindowName); 
[DllImport("user32.dll")] 
extern IntPtr PostMessage(System::IntPtr hWnd, System::UInt32 Msg, int wParam, int lParam); 
[assembly:RegistryPermissionAttribute(SecurityAction::RequestMinimum, All = "HKEY_CURRENT_USER")]; 
 
 
....blah blah blah you normal code...
 
 
void button1_Click(System::Object^  sender, System::EventArgs^  e) 
{ 
    // Open/show the Hot Virtual Keyboard 
    IntPtr hWnd; 
    hWnd = FindWindow("TFirstForm", "hvkFirstForm"); 
    PostMessage(hWnd, WM_CSKEYBOARD, 1, 0); 
} 
void button2_Click(System::Object^  sender, System::EventArgs^  e) 
{ 
        // close the Hot Virtual Keyboard 
    IntPtr hWnd; 
    hWnd = FindWindow("TFirstForm", "hvkFirstForm"); 
    PostMessage(hWnd, WM_CSKEYBOARD, 2, 0); 
} 
void button3_Click(System::Object^  sender, System::EventArgs^  e) 
{ 
    //Move the Hot Virtual Keyboard; Move it first then show it 
    IntPtr hWnd; 
    hWnd = FindWindow("TFirstForm", "hvkFirstForm"); 
    PostMessage(hWnd, WM_CSKEYBOARDMOVE, 200, 200); 
    PostMessage(hWnd, WM_CSKEYBOARD, 1, 0); 
} 
void button4_Click(System::Object^  sender, System::EventArgs^  e) 
{ 
    //Toggle the Hot Virtual Keyboard 
    IntPtr hWnd; 
    hWnd = FindWindow("TFirstForm", "hvkFirstForm"); 
    PostMessage(hWnd, WM_CSKEYBOARD, 4, 0); 
} 
void button5_Click(System::Object^  sender, System::EventArgs^  e) 
{ 
    //Fade the Hot Virtual Keyboard 
    IntPtr hWnd; 
    hWnd = FindWindow("TFirstForm", "hvkFirstForm"); 
    PostMessage(hWnd, WM_CSKEYBOARD, 3, 0); 
} 
void button6_Click(System::Object^  sender, System::EventArgs^  e) 
{ 
    //Change the keyboard type and show it 
    System::Object ^kname="NumPad"; 
 
    //Change the Registry entry for the required keyboard 
 
    RegistryKey ^key= Registry::CurrentUser->OpenSubKey ( "Software\ComfortSoftware\hvk",true); 
    key->SetValue("KeyboardName",kname); 
 
    //Open the keyboard 
    IntPtr hWnd; 
    hWnd = FindWindow("TFirstForm", "hvkFirstForm"); 
    PostMessage(hWnd, WM_CSKEYBOARD, 1, 0); 
}
Java Sample Code:
/*
* This file is heavily based on Jawin: http://jawinproject.sourceforge.net/
*
* assumes Hot Virtual Keyboard is loaded...
* 
*/

package client.keyboard;

import java.io.ByteArrayInputStream;
import java.io.IOException;

import org.jawin.COMException;
import org.jawin.FuncPtr;
import org.jawin.ReturnFlags;
import org.jawin.io.LittleEndianInputStream;
import org.jawin.io.LittleEndianOutputStream;
import org.jawin.io.NakedByteStream;

public class ComfortSoftwareKeyboard {

    protected static final String COMFORT_SOFTWARE_WINDOW_NAME = "hvkFirstForm";
    protected static final String COMFORT_SOFTWARE_CLASS_NAME = "TFirstForm";
    
    protected static final int WM_USER = 1024;
    protected static final int WM_CSKEYBOARD = WM_USER + 192;
    protected static final int WM_CSKEYBOARDMOVE = WM_USER + 193;

    protected static final Call FIND_WINDOW = new Call("USER32.DLL", "FindWindowW", "GG:I:", 8);
    protected static final Call POST_MESSAGE = new Call("USER32.DLL", "PostMessageW", "IIII:I:", 16);
    
    private static ComfortSoftwareKeyboard INSTANCE = new ComfortSoftwareKeyboard();

    public static ComfortSoftwareKeyboard getInstance() {
        return INSTANCE;
    }

    protected int getWindowHandle() throws COMException, IOException {
        FuncPtr findWindow = null;
        findWindow = new FuncPtr(FIND_WINDOW.getDllName(), FIND_WINDOW.getFunctionName());
        NakedByteStream bs = new NakedByteStream();
        LittleEndianOutputStream leo = new LittleEndianOutputStream(bs);
        leo.writeStringUnicode(COMFORT_SOFTWARE_CLASS_NAME);
        leo.writeStringUnicode(COMFORT_SOFTWARE_WINDOW_NAME);
        byte[] b = findWindow.invoke(FIND_WINDOW.getParameterDescription(), FIND_WINDOW.getStackSize(), bs, null,
                ReturnFlags.CHECK_FALSE);
        LittleEndianInputStream leis = new LittleEndianInputStream(
                new ByteArrayInputStream(b));
        int l = leis.readInt();
        findWindow.close();
        return l;
    }

    public int move(int x, int y) throws COMException, IOException {
        int hWnd = getWindowHandle();

        FuncPtr postMessage = null;
        postMessage = new FuncPtr(POST_MESSAGE.getDllName(), POST_MESSAGE.getFunctionName());
        NakedByteStream bs = new NakedByteStream();
        LittleEndianOutputStream leo = new LittleEndianOutputStream(bs);

        leo.writeInt(hWnd);
        leo.writeInt(WM_CSKEYBOARDMOVE);
        leo.writeInt(x);
        leo.writeInt(y);

        byte[] b = postMessage.invoke(POST_MESSAGE.getParameterDescription(), POST_MESSAGE.getStackSize(), bs, null,
                ReturnFlags.CHECK_FALSE);
        LittleEndianInputStream leis = new LittleEndianInputStream(
                new ByteArrayInputStream(b));
        int l = leis.readInt();
        postMessage.close();
        return l;
    }
    
    public int setVisible(boolean visible) throws COMException, IOException {
        int hWnd = getWindowHandle();

        FuncPtr postMessage = null;
        postMessage = new FuncPtr(POST_MESSAGE.getDllName(), POST_MESSAGE.getFunctionName());
        NakedByteStream bs = new NakedByteStream();
        LittleEndianOutputStream leo = new LittleEndianOutputStream(bs);

        leo.writeInt(hWnd);
        leo.writeInt(WM_CSKEYBOARD);
        leo.writeInt(visible ? 1 : 2);
        leo.writeInt(0);

        byte[] b = postMessage.invoke(POST_MESSAGE.getParameterDescription(), POST_MESSAGE.getStackSize(), bs, null,
                ReturnFlags.CHECK_FALSE);
        LittleEndianInputStream leis = new LittleEndianInputStream(
                new ByteArrayInputStream(b));
        int l = leis.readInt();
        postMessage.close();
        return l;
    }

    public static void main(String[] args) throws Exception {
        try {
            ComfortSoftwareKeyboard keyboard = ComfortSoftwareKeyboard.getInstance();
            keyboard.setVisible(true);
            Thread.sleep(1000);
            keyboard.setVisible(false);
            Thread.sleep(1000);
            keyboard.setVisible(true);
            for (int i = 0; i < 100;i++) {
                keyboard.move(i, i);
            }
        } catch (COMException e) {
        } finally {
        }
    }
}

class Call {
    private int stackSize;
    private String functionName;
    private String parameterDescription;
    private String dllName;
    
    public Call(String dllName, String functionName, String parameterDescription, int stackSize) {
        this.stackSize = stackSize;
        this.functionName = functionName;
        this.parameterDescription = parameterDescription;
        this.dllName = dllName;
    }
    public int getStackSize() {return stackSize;}
    public String getFunctionName() {return functionName;}
    public String getParameterDescription() {return parameterDescription;}
    public String getDllName() {return dllName;}
}

If you can't use Windows Messages then download and try these files:
https://hotvirtualkeyboard.com/files/ShowKB.exe
https://hotvirtualkeyboard.com/files/HideKB.exe
https://hotvirtualkeyboard.com/files/ToggleKB.exe

https://hotvirtualkeyboard.com/files/MoveTopKB.exe
https://hotvirtualkeyboard.com/files/MoveBottomKB.exe
https://hotvirtualkeyboard.com/files/MoveLeftKB.exe
https://hotvirtualkeyboard.com/files/MoveRightKB.exe

https://hotvirtualkeyboard.com/files/MoveKB.exe
(Command line format: MoveKB.exe Left Top)

https://hotvirtualkeyboard.com/files/SetNameKB.exe
(Command line format: SetNameKB.exe KeyboardName)


You can try how it works with Virtual Keyboard Commander

If you are writing kiosk software using HTML, you can use the special JavaScript functions to control the on-screen keyboard.

With JavaScript, you can show, hide, or move the keyboard. Just use the special JavaScript functions to add keyboard-related information to the browser caption, and the application will monitor the caption for changes.

Download the file with JavaScript functions and examples from here: https://hotvirtualkeyboard.com/commander.html

WM_CSKEYBOARDMOVE: Solving the issue with moving the keyboard when using multiple screens with different DPI.

For example, Screen 1 has a resolution of 2560x1440 and is set to "125% scale" in Windows display settings. Screen 2 is 1920x1080 and is set to "100% scale".

Open the Windows app compatibility settings of the hvk.exe file and set the DPI behavior to "Application", which means that the application manages all DPI-related calculations. With this setting activated, you can pass physical pixel values to the move function of your API, and the keyboard window is then moved to exactly that position.

If you want to activate this compatibility mode programmatically (e.g., with your own installer), you have to set the following registry key:
HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows NT\CurrentVersion\AppCompatFlags\Layers:
"C:\Program Files\HotVirtualKeyboard\hvk.exe"="~ HIGHDPIAWARE"

This will then apply to all users. Alternatively, you can place this key in the registry for the current user (HKCU).