Como mostrar, ocultar, mover ou redimensionar o teclado virtual em Java, C#, C++, Visual Basic, Delphi, etc.

Você pode usar mensagens do Windows para controlar o teclado virtual.

Exemplo:

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);

Código de exemplo em Visual Basic 2008 (VB.NET):

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

Código de exemplo em C#:

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

Código de exemplo em C++ (sintaxe CLR):

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); 
}

Código de exemplo em Java:

/*
* 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;}
}

Você pode testar como funciona com o Virtual Keyboard Commander

Se você estiver escrevendo software de quiosque usando HTML, poderá usar as funções JavaScript especiais para controlar o teclado virtual.

Com JavaScript, você pode mostrar, ocultar ou mover o teclado. Basta usar as funções JavaScript especiais para adicionar informações relacionadas ao teclado ao título do navegador, e o aplicativo monitorará o título em busca de alterações.

Baixe o arquivo com as funções e exemplos de JavaScript aqui: https://hotvirtualkeyboard.com/commander.html

WM_CSKEYBOARDMOVE: Solução do problema ao mover o teclado ao usar várias telas com DPI diferente.

Por exemplo, a Tela 1 tem resolução de 2560x1440 e está definida como "escala de 125%" nas configurações de exibição do Windows. A Tela 2 é 1920x1080 e está definida como "escala de 100%".

Abra as configurações de compatibilidade de aplicativos do Windows do arquivo hvk.exe e defina o comportamento de DPI como "Aplicativo", o que significa que o aplicativo gerencia todos os cálculos relacionados ao DPI. Com essa configuração ativada, você pode passar valores de pixels físicos para a função de movimentação da sua API, e a janela do teclado será movida exatamente para essa posição.

Se quiser ativar esse modo de compatibilidade de forma programática (por exemplo, com seu próprio instalador), você deve definir a seguinte chave do registro:
HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows NT\CurrentVersion\AppCompatFlags\Layers:
"C:\Program Files\HotVirtualKeyboard\hvk.exe"="~ HIGHDPIAWARE"

Isso será aplicado a todos os usuários. Como alternativa, você pode colocar essa chave no registro para o usuário atual (HKCU).