How to create a virtual keyboard?

Question

I have a form (Form1) and when I click on a button I would like to see a new window with several buttons that when I click on one of them would add a letter to a Form1 textbox. Is it possible to do this without having to create a new form? If not what is the best way to do this?

Update

What I want to do is simpler than the example above. How to make a virtual keyboard?

Answer 1

I recommend you create a new project (dll), then you can use in any other project your.

You can use native windows functions to simulate a pressed key in this link, you find a detailed explanation about the keybd_event function.

Below is a demonstration of how to implement

Keystroke constants

private const int VK_LBUTTON = 0X1; //Left mouse button.
private const int VK_RBUTTON = 0X2; //Right mouse button.
private const int VK_CANCEL = 0X3; //Used for control-break processing.
private const int VK_MBUTTON = 0X4; //''Middle mouse button (3-button mouse).

private const int KEYEVENTF_KEYUP = 0X2; // Release key
private const int VK_OEM_PERIOD = 0XBE; //.
private const int KEYEVENTF_EXTENDEDKEY = 0X1;
private const int VK_STARTKEY = 0X5B; //Start Menu key
private bool lockbool;
private bool numlockbool;
private bool ctrlbool;
private bool onoff;
private const int VK_OEM_COMMA = 0XBC; //, comma
public const int VK_0 = 0x30;
public const int VK_1 = 0x31;
public const int VK_2 = 0x32;
public const int VK_3 = 0x33;
public const int VK_4 = 0x34;
public const int VK_5 = 0x35;
public const int VK_6 = 0x36;
public const int VK_7 = 0x37;
public const int VK_8 = 0x38;
public const int VK_9 = 0x39;
public const int VK_A = 0x41;
public const int VK_B = 0x42;
public const int VK_C = 0x43;
public const int VK_D = 0x44;
public const int VK_E = 0x45;
public const int VK_F = 0x46;
public const int VK_G = 0x47;
public const int VK_H = 0x48;
public const int VK_I = 0x49;
public const int VK_J = 0x4A;
public const int VK_K = 0x4B;
public const int VK_L = 0x4C;
public const int VK_M = 0x4D;
public const int VK_N = 0x4E;
public const int VK_O = 0x4F;
public const int VK_P = 0x50;
public const int VK_Q = 0x51;
public const int VK_R = 0x52;
public const int VK_S = 0x53;
public const int VK_T = 0x54;
public const int VK_U = 0x55;
public const int VK_V = 0x56;
public const int VK_W = 0x57;
public const int VK_X = 0x58;
public const int VK_Y = 0x59;
public const int VK_Z = 0x5A;

public const int VK_BACK = 0x08;
public const int VK_TAB = 0x09;
public const int VK_CLEAR = 0x0C;
public const int VK_RETURN = 0x0D;
public const int VK_SHIFT = 0x10;
public const int VK_CONTROL = 0x11;
public const int VK_MENU = 0x12;
public const int VK_PAUSE = 0x13;
public const int VK_CAPITAL = 0x14;
public const int VK_KANA = 0x15;
public const int VK_HANGEUL = 0x15;
public const int VK_HANGUL = 0x15;
public const int VK_JUNJA = 0x17;
public const int VK_FINAL = 0x18;
public const int VK_HANJA = 0x19;
public const int VK_KANJI = 0x19;
public const int VK_ESCAPE = 0x1B;
public const int VK_CONVERT = 0x1C;
public const int VK_NONCONVERT = 0x1D;
public const int VK_ACCEPT = 0x1E;
public const int VK_MODECHANGE = 0x1F;
public const int VK_SPACE = 0x20;
public const int VK_PRIOR = 0x21;
public const int VK_NEXT = 0x22;
public const int VK_END = 0x23;
public const int VK_HOME = 0x24;
public const int VK_LEFT = 0x25;
public const int VK_UP = 0x26;
public const int VK_RIGHT = 0x27;
public const int VK_DOWN = 0x28;
public const int VK_SELECT = 0x29;
public const int VK_PRINT = 0x2A;
public const int VK_EXECUTE = 0x2B;
public const int VK_SNAPSHOT = 0x2C;
public const int VK_INSERT = 0x2D;
public const int VK_DELETE = 0x2E;
public const int VK_HELP = 0x2F;
public const int VK_LWIN = 0x5B;
public const int VK_RWIN = 0x5C;
public const int VK_APPS = 0x5D;
public const int VK_SLEEP = 0x5F;
public const int VK_NUMPAD0 = 0x60;
public const int VK_NUMPAD1 = 0x61;
public const int VK_NUMPAD2 = 0x62;
public const int VK_NUMPAD3 = 0x63;
public const int VK_NUMPAD4 = 0x64;
public const int VK_NUMPAD5 = 0x65;
public const int VK_NUMPAD6 = 0x66;
public const int VK_NUMPAD7 = 0x67;
public const int VK_NUMPAD8 = 0x68;
public const int VK_NUMPAD9 = 0x69;
public const int VK_MULTIPLY = 0x6A;
public const int VK_ADD = 0x6B;
public const int VK_SEPARATOR = 0x6C;
public const int VK_SUBTRACT = 0x6D;
public const int VK_DECIMAL = 0x6E;
public const int VK_DIVIDE = 0x6F;
public const int VK_F1 = 0x70;
public const int VK_F2 = 0x71;
public const int VK_F3 = 0x72;
public const int VK_F4 = 0x73;
public const int VK_F5 = 0x74;
public const int VK_F6 = 0x75;
public const int VK_F7 = 0x76;
public const int VK_F8 = 0x77;
public const int VK_F9 = 0x78;
public const int VK_F10 = 0x79;
public const int VK_F11 = 0x7A;
public const int VK_F12 = 0x7B;
public const int VK_F13 = 0x7C;
public const int VK_F14 = 0x7D;
public const int VK_F15 = 0x7E;
public const int VK_F16 = 0x7F;
public const int VK_F17 = 0x80;
public const int VK_F18 = 0x81;
public const int VK_F19 = 0x82;
public const int VK_F20 = 0x83;
public const int VK_F21 = 0x84;
public const int VK_F22 = 0x85;
public const int VK_F23 = 0x86;
public const int VK_F24 = 0x87;
public const int VK_NUMLOCK = 0x90;
public const int VK_SCROLL = 0x91;

Implementation of keybd_event using Dllimport for interoperability

[System.Runtime.InteropServices.DllImport("user32", EntryPoint = "keybd_event", ExactSpelling = true, CharSet = System.Runtime.InteropServices.CharSet.Ansi, SetLastError = true)]
    public static extern long keybd_event(byte bVk, byte bScan, long dwFlags, long dwExtraInfo);

and on your button event for example A key, just call the native windows function

keybd_event(VK_A, 0, 0, 0);
keybd_event(VK_A, 0, KEYEVENTF_KEYUP, 0);

The code described above was taken from this link.

So your keyboard will work in any application, such as notepad, CMD.. and your application...

I hope I’ve helped.