How to perform .Onkey Event in an Excel Add-In created with Visual Studio 2010?

Question

I am creating an Excel Add-In using Visual Studio 2010. I would like to run some code when users clicks a combination of keys.

Here is the code I have got

Answer 1

"I would like to run some code when users presses a combination of keys."

Its tricky and to do it without any external dependencies resort to Keyboard hooking to achieve it with a VSTO Excel Add-in:

Imports System
Imports System.Runtime.CompilerServices
Imports System.Runtime.InteropServices
Imports System.Windows.Forms

Friend Class KeyboardHooking
    ' Methods
     _
    Private Shared Function CallNextHookEx(ByVal hhk As IntPtr, ByVal nCode As Integer, ByVal wParam As IntPtr, ByVal lParam As IntPtr) As IntPtr
    End Function

     _
    Private Shared Function GetModuleHandle(ByVal lpModuleName As String) As IntPtr
    End Function

    Private Shared Function HookCallback(ByVal nCode As Integer, ByVal wParam As IntPtr, ByVal lParam As IntPtr) As Integer
        If ((nCode >= 0) AndAlso (nCode = 0)) Then
            Dim keyData As Keys = DirectCast(CInt(wParam), Keys)
            If (((BindingFunctions.IsKeyDown(Keys.ControlKey) AndAlso BindingFunctions.IsKeyDown(Keys.ShiftKey)) AndAlso BindingFunctions.IsKeyDown(keyData)) AndAlso (keyData = Keys.D7)) Then
'DO SOMETHING HERE
            End If
            If ((BindingFunctions.IsKeyDown(Keys.ControlKey) AndAlso BindingFunctions.IsKeyDown(keyData)) AndAlso (keyData = Keys.D7)) Then
'DO SOMETHING HERE
            End If
        End If
        Return CInt(KeyboardHooking.CallNextHookEx(KeyboardHooking._hookID, nCode, wParam, lParam))
    End Function

    Public Shared Sub ReleaseHook()
        KeyboardHooking.UnhookWindowsHookEx(KeyboardHooking._hookID)
    End Sub

    Public Shared Sub SetHook()
        KeyboardHooking._hookID = KeyboardHooking.SetWindowsHookEx(2, KeyboardHooking._proc, IntPtr.Zero, Convert.ToUInt32(AppDomain.GetCurrentThreadId))
    End Sub

     _
    Private Shared Function SetWindowsHookEx(ByVal idHook As Integer, ByVal lpfn As LowLevelKeyboardProc, ByVal hMod As IntPtr, ByVal dwThreadId As UInt32) As IntPtr
    End Function

     _
    Private Shared Function UnhookWindowsHookEx(ByVal hhk As IntPtr) As  Boolean
    End Function


    ' Fields
    Private Shared _hookID As IntPtr = IntPtr.Zero
    Private Shared _proc As LowLevelKeyboardProc = New LowLevelKeyboardProc(AddressOf KeyboardHooking.HookCallback)
    Private Const WH_KEYBOARD As Integer = 2
    Private Const WH_KEYBOARD_LL As Integer = 13
    Private Const WM_KEYDOWN As Integer = &H100

    ' Nested Types
    Public Delegate Function LowLevelKeyboardProc(ByVal nCode As Integer, ByVal wParam As IntPtr, ByVal lParam As IntPtr) As Integer
End Class

Public Class BindingFunctions
    ' Methods
     _
    Private Shared Function GetKeyState(ByVal nVirtKey As Integer) As Short
    End Function

    Public Shared Function IsKeyDown(ByVal keys As Keys) As Boolean
        Return ((BindingFunctions.GetKeyState(CInt(keys)) And &H8000) = &H8000)
    End Function

End Class

C# version - the original that the above vb.net code was converted from - but I had to use Reflector as CodeConverter & devfusion didn't do it correctly.

class KeyboardHooking
{
[DllImport("user32.dll", CharSet = CharSet.Auto, SetLastError = true)]
private static extern IntPtr SetWindowsHookEx(int idHook, LowLevelKeyboardProc lpfn, IntPtr hMod,
    uint dwThreadId);

[DllImport("user32.dll", CharSet = CharSet.Auto, SetLastError = true)]
[return: MarshalAs(UnmanagedType.Bool)]
private static extern bool UnhookWindowsHookEx(IntPtr hhk);

[DllImport("user32.dll", CharSet = CharSet.Auto, SetLastError = true)]
private static extern IntPtr CallNextHookEx(IntPtr hhk, int nCode, IntPtr wParam, IntPtr lParam);

[DllImport("kernel32.dll", CharSet = CharSet.Auto, SetLastError = true)]
private static extern IntPtr GetModuleHandle(string lpModuleName);

public delegate int LowLevelKeyboardProc(int nCode, IntPtr wParam, IntPtr lParam);
private static LowLevelKeyboardProc _proc = HookCallback;
private static IntPtr _hookID = IntPtr.Zero;

//declare the mouse hook constant.
//For other hook types, you can obtain these values from Winuser.h in the Microsoft SDK.

private const int WH_KEYBOARD = 2; // mouse
private const int HC_ACTION = 0;

private const int WH_KEYBOARD_LL = 13; // keyboard
private const int WM_KEYDOWN = 0x0100;

public static void SetHook()
{
    // Ignore this compiler warning, as SetWindowsHookEx doesn't work with ManagedThreadId
    #pragma warning disable 618
    _hookID = SetWindowsHookEx(WH_KEYBOARD, _proc, IntPtr.Zero, (uint)AppDomain.GetCurrentThreadId());
    #pragma warning restore 618

}

public static void ReleaseHook()
{
    UnhookWindowsHookEx(_hookID);
}

//Note that the custom code goes in this method the rest of the class stays the same.
//It will trap if BOTH keys are pressed down.
private static int HookCallback(int nCode, IntPtr wParam, IntPtr lParam)
{
    if (nCode < 0)
    {
        return (int)CallNextHookEx(_hookID, nCode, wParam, lParam);
    }
    else
    {

        if (nCode == HC_ACTION)
        {
            Keys keyData = (Keys)wParam;

            // CTRL + SHIFT + 7
            if ((BindingFunctions.IsKeyDown(Keys.ControlKey) == true)
                && (BindingFunctions.IsKeyDown(Keys.ShiftKey) == true)
                && (BindingFunctions.IsKeyDown(keyData) == true) && (keyData == Keys.D7))
            {
                // DO SOMETHING HERE
            }

            // CTRL + 7
            if ((BindingFunctions.IsKeyDown(Keys.ControlKey) == true)
                && (BindingFunctions.IsKeyDown(keyData) == true) && (keyData == Keys.D7))
            {
                // DO SOMETHING HERE
            }



        }
        return (int)CallNextHookEx(_hookID, nCode, wParam, lParam);
    }
}
}

public class BindingFunctions
{
[DllImport("user32.dll")]
static extern short GetKeyState(int nVirtKey);

public static bool IsKeyDown(Keys keys)
{
    return (GetKeyState((int)keys) & 0x8000) == 0x8000;
}

}

You'll need to put code in the HookCallback() method in the above code to trap events when key combinations are pressed, I've given you two examples Ctrl + Shift + 7 and Ctrl + 7 to get you going.

Then in your Excel AddIn wire it up:

Private Sub ThisAddIn_Startup() Handles Me.Startup

'enable keyboard intercepts
KeyboardHooking.SetHook()

And dont forget to disable it when your done:

Private Sub ThisAddIn_Shutdown() Handles Me.Shutdown

'disable keyboard intercepts
KeyboardHooking.ReleaseHook()