C# Signature:

[DllImport("user32.dll")]
static extern short GetKeyState(VirtualKeyStates nVirtKey);

User-Defined Types:

VK

Notes:

Here are some sample values for nVirtKey:

private enum VirtualKeyStates : int
{
    VK_LBUTTON       = 0x01,
    VK_RBUTTON       = 0x02,
    VK_CANCEL    = 0x03,
    VK_MBUTTON       = 0x04,
    //
    VK_XBUTTON1      = 0x05,
    VK_XBUTTON2      = 0x06,
    //
    VK_BACK      = 0x08,
    VK_TAB       = 0x09,
    //
    VK_CLEAR     = 0x0C,
    VK_RETURN    = 0x0D,
    //
    VK_SHIFT     = 0x10,
    VK_CONTROL       = 0x11,
    VK_MENU      = 0x12,
    VK_PAUSE     = 0x13,
    VK_CAPITAL       = 0x14,
    //
    VK_KANA      = 0x15,
    VK_HANGEUL       = 0x15,  /* old name - should be here for compatibility */
    VK_HANGUL    = 0x15,
    VK_JUNJA     = 0x17,
    VK_FINAL     = 0x18,
    VK_HANJA     = 0x19,
    VK_KANJI     = 0x19,
    //
    VK_ESCAPE    = 0x1B,
    //
    VK_CONVERT       = 0x1C,
    VK_NONCONVERT    = 0x1D,
    VK_ACCEPT    = 0x1E,
    VK_MODECHANGE    = 0x1F,
    //
    VK_SPACE     = 0x20,
    VK_PRIOR     = 0x21,
    VK_NEXT      = 0x22,
    VK_END       = 0x23,
    VK_HOME      = 0x24,
    VK_LEFT      = 0x25,
    VK_UP        = 0x26,
    VK_RIGHT     = 0x27,
    VK_DOWN      = 0x28,
    VK_SELECT    = 0x29,
    VK_PRINT     = 0x2A,
    VK_EXECUTE       = 0x2B,
    VK_SNAPSHOT      = 0x2C,
    VK_INSERT    = 0x2D,
    VK_DELETE    = 0x2E,
    VK_HELP      = 0x2F,
    //
    VK_LWIN      = 0x5B,
    VK_RWIN      = 0x5C,
    VK_APPS      = 0x5D,
    //
    VK_SLEEP     = 0x5F,
    //
    VK_NUMPAD0       = 0x60,
    VK_NUMPAD1       = 0x61,
    VK_NUMPAD2       = 0x62,
    VK_NUMPAD3       = 0x63,
    VK_NUMPAD4       = 0x64,
    VK_NUMPAD5       = 0x65,
    VK_NUMPAD6       = 0x66,
    VK_NUMPAD7       = 0x67,
    VK_NUMPAD8       = 0x68,
    VK_NUMPAD9       = 0x69,
    VK_MULTIPLY      = 0x6A,
    VK_ADD       = 0x6B,
    VK_SEPARATOR     = 0x6C,
    VK_SUBTRACT      = 0x6D,
    VK_DECIMAL       = 0x6E,
    VK_DIVIDE    = 0x6F,
    VK_F1        = 0x70,
    VK_F2        = 0x71,
    VK_F3        = 0x72,
    VK_F4        = 0x73,
    VK_F5        = 0x74,
    VK_F6        = 0x75,
    VK_F7        = 0x76,
    VK_F8        = 0x77,
    VK_F9        = 0x78,
    VK_F10       = 0x79,
    VK_F11       = 0x7A,
    VK_F12       = 0x7B,
    VK_F13       = 0x7C,
    VK_F14       = 0x7D,
    VK_F15       = 0x7E,
    VK_F16       = 0x7F,
    VK_F17       = 0x80,
    VK_F18       = 0x81,
    VK_F19       = 0x82,
    VK_F20       = 0x83,
    VK_F21       = 0x84,
    VK_F22       = 0x85,
    VK_F23       = 0x86,
    VK_F24       = 0x87,
    //
    VK_NUMLOCK       = 0x90,
    VK_SCROLL    = 0x91,
    //
    VK_OEM_NEC_EQUAL = 0x92,   // '=' key on numpad
    //
    VK_OEM_FJ_JISHO  = 0x92,   // 'Dictionary' key
    VK_OEM_FJ_MASSHOU= 0x93,   // 'Unregister word' key
    VK_OEM_FJ_TOUROKU= 0x94,   // 'Register word' key
    VK_OEM_FJ_LOYA   = 0x95,   // 'Left OYAYUBI' key
    VK_OEM_FJ_ROYA   = 0x96,   // 'Right OYAYUBI' key
    //
    VK_LSHIFT    = 0xA0,
    VK_RSHIFT    = 0xA1,
    VK_LCONTROL      = 0xA2,
    VK_RCONTROL      = 0xA3,
    VK_LMENU     = 0xA4,
    VK_RMENU     = 0xA5,
    //
    VK_BROWSER_BACK       = 0xA6,
    VK_BROWSER_FORWARD    = 0xA7,
    VK_BROWSER_REFRESH    = 0xA8,
    VK_BROWSER_STOP       = 0xA9,
    VK_BROWSER_SEARCH     = 0xAA,
    VK_BROWSER_FAVORITES  = 0xAB,
    VK_BROWSER_HOME       = 0xAC,
    //
    VK_VOLUME_MUTE    = 0xAD,
    VK_VOLUME_DOWN    = 0xAE,
    VK_VOLUME_UP      = 0xAF,
    VK_MEDIA_NEXT_TRACK   = 0xB0,
    VK_MEDIA_PREV_TRACK   = 0xB1,
    VK_MEDIA_STOP     = 0xB2,
    VK_MEDIA_PLAY_PAUSE   = 0xB3,
    VK_LAUNCH_MAIL    = 0xB4,
    VK_LAUNCH_MEDIA_SELECT= 0xB5,
    VK_LAUNCH_APP1    = 0xB6,
    VK_LAUNCH_APP2    = 0xB7,
    //
    VK_OEM_1     = 0xBA,   // ';:' for US
    VK_OEM_PLUS      = 0xBB,   // '+' any country
    VK_OEM_COMMA     = 0xBC,   // ',' any country
    VK_OEM_MINUS     = 0xBD,   // '-' any country
    VK_OEM_PERIOD    = 0xBE,   // '.' any country
    VK_OEM_2     = 0xBF,   // '/?' for US
    VK_OEM_3     = 0xC0,   // '`~' for US
    //
    VK_OEM_4     = 0xDB,  //  '[{' for US
    VK_OEM_5     = 0xDC,  //  '\|' for US
    VK_OEM_6     = 0xDD,  //  ']}' for US
    VK_OEM_7     = 0xDE,  //  ''"' for US
    VK_OEM_8     = 0xDF,
    //
    VK_OEM_AX    = 0xE1,  //  'AX' key on Japanese AX kbd
    VK_OEM_102       = 0xE2,  //  "<>" or "\|" on RT 102-key kbd.
    VK_ICO_HELP      = 0xE3,  //  Help key on ICO
    VK_ICO_00    = 0xE4,  //  00 key on ICO
    //
    VK_PROCESSKEY    = 0xE5,
    //
    VK_ICO_CLEAR     = 0xE6,
    //
    VK_PACKET    = 0xE7,
    //
    VK_OEM_RESET     = 0xE9,
    VK_OEM_JUMP      = 0xEA,
    VK_OEM_PA1       = 0xEB,
    VK_OEM_PA2       = 0xEC,
    VK_OEM_PA3       = 0xED,
    VK_OEM_WSCTRL    = 0xEE,
    VK_OEM_CUSEL     = 0xEF,
    VK_OEM_ATTN      = 0xF0,
    VK_OEM_FINISH    = 0xF1,
    VK_OEM_COPY      = 0xF2,
    VK_OEM_AUTO      = 0xF3,
    VK_OEM_ENLW      = 0xF4,
    VK_OEM_BACKTAB   = 0xF5,
    //
    VK_ATTN      = 0xF6,
    VK_CRSEL     = 0xF7,
    VK_EXSEL     = 0xF8,
    VK_EREOF     = 0xF9,
    VK_PLAY      = 0xFA,
    VK_ZOOM      = 0xFB,
    VK_NONAME    = 0xFC,
    VK_PA1       = 0xFD,
    VK_OEM_CLEAR     = 0xFE,
}

Tips & Tricks:

The Enum Keys in System.Windows.Forms has the key code used for this function, so you don't need to define const

Do not use (ByVal nVirtKey As Long) but (ByVal nVirtKey As Short), in VS2005, in fact, in the first case you will have a PInvoke error.

Sample Code:

This Sample use this API to create a new textbox to support overwrite mode, testing the state of insert key.

Imports System.Windows.Forms

Public Class MinhaNovaTextbox

  Inherits System.Windows.Forms.TextBox

  Dim bInserting As Boolean = True

  Private Declare Function GetKeyState _
      Lib "user32" (ByVal nVirtKey As Short) As Integer

  Public Sub New()
    MyBase.New()
    bInserting = GetKeyState(Keys.Insert)
  End Sub

  Protected Overrides Sub OnKeyPress(ByVal e As System.Windows.Forms.KeyPressEventArgs)
    bInserting = GetKeyState(Keys.Insert)
    If Not bInserting Then
      Me.SelectionLength = 1
    End If
    MyBase.OnKeyPress(e)
  End Sub

End Class

Alternative Managed API:

Do you know one? Please contribute it!

Please edit this page!

Do you have...

• helpful tips or sample code to share for using this API in managed code?
• corrections to the existing content?
• variations of the signature you want to share?
• additional languages you want to include?

Select "Edit This Page" on the right hand toolbar and edit it! Or add new pages containing supporting types needed for this API (structures, delegates, and more).