Blocking keyboard input to external application - c#

I am creating a bot program that opens an external application and does a series of keyboard commands. Unfortunately, the user can press a keyboard button while it is botting and get it out of sequence. Is there a way to disable the keyboard for that application only? The only thing I have found is BlockInput which does not work:
[DllImport("user32.dll", EntryPoint = "BlockInput")]
[return: MarshalAs(UnmanagedType.Bool)]
public static extern bool BlockInput([MarshalAs(UnmanagedType.Bool)] bool fBlockIt);
private void button_Click(object sender, EventArgs e)
{
BlockInput(true);
//Open application and do macro
BlockInput(false);
}
EDIT:
So I found a solution that worked better than what I asked for. I'm not answer my own question though because I didn't block JUST the external application; I was able to block all mouse and keyboard commands to the computer.
What I did was right-clicked on the Namespace under the Solution in Solution Explorer and selected Add > New Item. Add an Application Manifest File. Click on the newly created app.manifest file. Read the green that says to replace the requestedExecutionLevel and replace the current one with "requireAdministrator". Add the following code to the program:
[DllImport("user32.dll", SetLastError = true)]
static extern bool BlockInput(bool fBlockIt);
private void button_Click(object sender, EventArgs e)
{
BlockInput(true);
//Blocked code
BlockInput(false);
}

I find a good topic on that subject test if it fit you : How to intercept all the keyboard events and prevent losing focus in a WinForms application? (test the return -1 on the call back).
The code of the link :
using System;
using System.Diagnostics;
using System.Windows.Forms;
using System.Runtime.InteropServices;
class InterceptKeys
{
private const int WH_KEYBOARD_LL = 13;
private const int WM_KEYDOWN = 0x0100;
private static LowLevelKeyboardProc _proc = HookCallback;
private static IntPtr _hookID = IntPtr.Zero;
public static void Main()
{
_hookID = SetHook(_proc);
Application.Run();
UnhookWindowsHookEx(_hookID);
}
private static IntPtr SetHook(LowLevelKeyboardProc proc)
{
using (Process curProcess = Process.GetCurrentProcess())
using (ProcessModule curModule = curProcess.MainModule)
{
return SetWindowsHookEx(WH_KEYBOARD_LL, proc,
GetModuleHandle(curModule.ModuleName), 0);
}
}
private delegate IntPtr LowLevelKeyboardProc(
int nCode, IntPtr wParam, IntPtr lParam);
private static IntPtr HookCallback(
int nCode, IntPtr wParam, IntPtr lParam)
{
if (nCode >= 0 && wParam == (IntPtr)WM_KEYDOWN)
{
int vkCode = Marshal.ReadInt32(lParam);
Console.WriteLine((Keys)vkCode);
}
return -1;
}
[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);
}

Related

C# Detect ESC press key anywhere

I have a C# windowed application running and I want to close it when I press ESC from anywhere, even when my application does not have focus. How can I implement this?
I found some hook up keyboard which is Low Level Control I have no idea and don't understand.
Use this class:
using System;
using System.Diagnostics;
using System.Runtime.InteropServices;
using System.Windows.Forms;
namespace myNameSpace
{
class InterceptKeys
{
private const int WH_KEYBOARD_LL = 13;
private const int WM_KEYDOWN = 0x0100;
private const int WM_ALTDOWN = 0x0104;
private static LowLevelKeyboardProc _proc = HookCallback;
private static IntPtr _hookID = IntPtr.Zero;
public static void Start()
{
_hookID = SetHook(_proc);
}
public static void Stop()
{
UnhookWindowsHookEx(_hookID);
}
public static event KeyEventHandler OnKeyDown;
private static IntPtr SetHook(LowLevelKeyboardProc proc)
{
using (Process curProcess = Process.GetCurrentProcess())
using (ProcessModule curModule = curProcess.MainModule)
{
return SetWindowsHookEx(WH_KEYBOARD_LL, proc,
GetModuleHandle(curModule.ModuleName), 0);
}
}
private delegate IntPtr LowLevelKeyboardProc(
int nCode, IntPtr wParam, IntPtr lParam);
private static IntPtr HookCallback(
int nCode, IntPtr wParam, IntPtr lParam)
{
if (nCode >= 0 && (wParam == (IntPtr)WM_KEYDOWN || wParam == (IntPtr)WM_ALTDOWN))
{
var vkCode = (Keys)Marshal.ReadInt32(lParam);
OnKeyDown(null, new KeyEventArgs(vkCode));
}
return CallNextHookEx(_hookID, nCode, wParam, lParam);
}
[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);
}
}
In this way:
myNameSpace.InterceptKeys.OnKeyDown+= new KeyEventHandler(myKeyDown);
myNameSpace.InterceptKeys.Start();
that onKeyDown can be like this:
void myKeyDown(object sender, KeyEventArgs e)
{
// Some code for closing you form
// or any thing you need after press Esc
// with e.KeyCode
};
if you want you can set global hook with http://www.codeproject.com/Articles/7294/Processing-Global-Mouse-and-Keyboard-Hooks-in-C
For those looking for a complete solution to detect global key presses and also make key presses, I've figured it all out and put the code in pastebin.com to "never" be deleted. Note especially InterceptKeys.cs here (do a Ctrl+F):
http://pastebin.com/u7FUhgYr
^ This code is complete, but it's sub-optimal.
Then I improved the code a bit (one change is the new SendKeys function I created which sends whatever key presses/releases you want - much easier to use!). This class here, MakroKeys:
http://pastebin.com/Dedx6hRw
has two static functions that can be used to convert from string to System.Windows.Forms.Keys and vice versa (which would be useful if you want the user to be able to input their own key via text and/or display the currently pressed key via text); and this has the improved MainForm.cs code to go with it (containing the SendKeys function):
http://pastebin.com/BXzmWeMK
(Note the MakroKeys.GetKey("lcontrolkey") call, which demonstrates the usage of that functionality.)
With all of this combined you can do some pretty amazing things. Note also that because this is importing DLL's and calling Windows API functions, you can do this rather easily in e.g. c++ too. You're welcome, world. ;)

Listening for global keyboard events while computer is locked

I'm experimenting with keyboard events and what you can do with them and I've found alot of tutorials and open source libraries to listen for keyboard events in other processes. I came up with the idea to create a simple 'hack' to lock the computer and then listen for the keyboard events. I figured I could force the user to input their password to unlock their computer and then I would've listened to the user input and thus obtaining the password specified. Here is the simple sample code I found on the internet which will listen for global keyboard events:
using System;
using System.Diagnostics;
using System.Windows.Forms;
using System.Runtime.InteropServices;
class InterceptKeys
{
private const int WH_KEYBOARD_LL = 13;
private const int WM_KEYDOWN = 0x0100;
private static LowLevelKeyboardProc _proc = HookCallback;
private static IntPtr _hookID = IntPtr.Zero;
public static void Main()
{
_hookID = SetHook(_proc);
Application.Run();
UnhookWindowsHookEx(_hookID);
}
private static IntPtr SetHook(LowLevelKeyboardProc proc)
{
using (Process curProcess = Process.GetCurrentProcess())
using (ProcessModule curModule = curProcess.MainModule)
{
return SetWindowsHookEx(WH_KEYBOARD_LL, proc,
GetModuleHandle(curModule.ModuleName), 0);
}
}
private delegate IntPtr LowLevelKeyboardProc(
int nCode, IntPtr wParam, IntPtr lParam);
private static IntPtr HookCallback(
int nCode, IntPtr wParam, IntPtr lParam)
{
if (nCode >= 0 && wParam == (IntPtr)WM_KEYDOWN)
{
int vkCode = Marshal.ReadInt32(lParam);
Console.WriteLine((Keys)vkCode);
}
return CallNextHookEx(_hookID, nCode, wParam, lParam);
}
[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);
}
This works out quiet well, but for some reason there seems to be a exception when listening to keyboard inputs when the computer is locked? I'm not sure why it doesn't work, perhaps it's a security thing. Anyways it would be awesome if one could do this.
If this is on Windows, the locked screen is actually a different Window Station and is not owned by the interactive user, so therefore the interactive user cannot interact with it in any way (as a security measure). To interact with the lock screen, and logon in general, take a look at creating a Credential Provider

Low Level Keyboard Hooks installs automatically and slows down computer?

I am using Keyboard Low Level hooks in a desktop application to monitor user activity. Code i am using for hooks is give below.
In this code (upto my knowledge) when I have to start monitoring user activity I call SetHook() this will install hook and I can monitor keys pressed on keyboard. When I want to stop capturing keys i just call UnHook() method.
Problem is when my application starts (SetHook() method is not called yet) my application install hooks automatically and it slows down system. System hangs for for 2-3 seconds every 1 mint.
To diagnose the problem I commented out all the below mentioned code and installed application. Now system works absolutely fine.
I am not sure why is this happening?
Why my application start capturing keys even I did not called SetHook() method yet?
Is there is any other way to capture global keys without using hooks?
Code for Hooks:
public static class WinKeyCapture5 {
private const int WH_KEYBOARD_LL = 13;
private const int WM_KEYDOWN = 0x0100;
private static LowLevelKeyboardProc _proc = HookCallback;
public static DateTime LastKeyPressTime;
public static void SetHook()
{
SetHook(_proc);
}
public static void UnHook()
{
UnhookWindowsHookEx(_hookID);
}
private static IntPtr SetHook(LowLevelKeyboardProc proc)
{
using (Process curProcess = Process.GetCurrentProcess())
using (ProcessModule curModule = curProcess.MainModule)
{
return SetWindowsHookEx(WH_KEYBOARD_LL, proc, GetModuleHandle(curModule.ModuleName), 0);
}
}
private static IntPtr _hookID = IntPtr.Zero;
private delegate IntPtr LowLevelKeyboardProc(int nCode, IntPtr wParam, IntPtr lParam);
private static IntPtr HookCallback(int nCode, IntPtr wParam, IntPtr lParam)
{
//if (nCode >= 0 && wParam == (IntPtr)WM_KEYDOWN)
//{
int vkCode = Marshal.ReadInt32(lParam);
//if (vkCode == 44)
//ScreenCapture.Load();
LastKeyPressTime = System.DateTime.Now;
//}
return CallNextHookEx(_hookID, nCode, wParam, lParam);
}
[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);
}

Program is unresponsive for a couple of seconds

I found a way to capture the Print Screen button in C#. When pressing Alt + Print Screen a simple messagebox pops up saying the keys have been pressed. But it's unresponsive for a couple of seconds right after. I have no idea why this is happening.
Here's the code I use:
static class Program
{
/// <summary>
/// The main entry point for the application.
/// </summary>
[STAThread]
static void Main()
{
Application.EnableVisualStyles();
Application.SetCompatibleTextRenderingDefault(false);
_hookID = SetHook(_proc);
Application.Run(new Form1());
UnhookWindowsHookEx(_hookID);
}
/****************************************/
private const int WH_KEYBOARD_LL = 13;
//private const int WH_KEYBOARD_LL = 13;
private const int WM_KEYDOWN = 0x0100;
private const int VK_F1 = 0x70;
private static LowLevelKeyboardProc _proc = HookCallback;
private static IntPtr _hookID = IntPtr.Zero;
private static IntPtr SetHook(LowLevelKeyboardProc proc)
{
using (Process curProcess = Process.GetCurrentProcess())
using (ProcessModule curModule = curProcess.MainModule)
{
return SetWindowsHookEx(WH_KEYBOARD_LL, proc,
GetModuleHandle(curModule.ModuleName), 0);
}
}
private delegate IntPtr LowLevelKeyboardProc(
int nCode, IntPtr wParam, IntPtr lParam);
private static IntPtr HookCallback(
int nCode, IntPtr wParam, IntPtr lParam)
{
if (nCode >= 0)
{
Keys number = (Keys)Marshal.ReadInt32(lParam);
if (number == Keys.PrintScreen)
{
if ((wParam == (IntPtr)260 && Keys.Alt == Control.ModifierKeys && number == Keys.PrintScreen))
{
MessageBox.Show("You pressed alt+ print screen");
}
}
}
return CallNextHookEx(IntPtr.Zero, nCode, wParam, lParam);
}
[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);
}
Does anyone have a clue why it's hanging after the messagebox?
Windows cannot dispatch the next keyboard message until the hook callback finished executing. Clearly you do not want to use MessageBox.Show(), that blocks the callback. Windows puts up with that for several seconds before it declares your code broken and disables the hook.
Use Debug.Print() instead.

How to get the "KeyPress" event from a Word 2010 Addin (developed in C#)?

How can I "catch" the KeyPress event from a Word 2010 Addin developed in C#?
Note: I'm not looking for "complex" solutions like hooking stuff, but for the nice and tidy
.NET even from the object model.
The application object I have "in my hands" is:
Microsoft.Office.Interop.Word.Application
Best Regards
Unfortunately there is nothing built-in in the Word API or VSTO which can pick up key strokes, more info on this can be found here
I've been searching for a feasible solution for some time but the best I could come up with was handling it through Windows API using hooks, it's likely you will reach the same conclusion so here's an example:
You'll need to add a using directive to the following assemblies:
using System;
using System.Diagnostics;
using System.Runtime.InteropServices;
using System.Threading;
using System.Windows.Forms;
And here's the hook:
public partial class ThisAddIn
{
private const int WH_KEYBOARD_LL = 13;
private const int WM_KEYDOWN = 0x0100;
private static IntPtr hookId = IntPtr.Zero;
private delegate IntPtr HookProcedure(int nCode, IntPtr wParam, IntPtr lParam);
private static HookProcedure procedure = HookCallback;
[DllImport("kernel32.dll", CharSet = CharSet.Auto, SetLastError = true)]
private static extern IntPtr GetModuleHandle(string lpModuleName);
[DllImport("user32.dll", SetLastError = true)]
private static extern bool UnhookWindowsHookEx(IntPtr hhk);
[DllImport("user32.dll", CharSet = CharSet.Auto, SetLastError = true)]
private static extern IntPtr SetWindowsHookEx(int idHook, HookProcedure lpfn, IntPtr hMod, uint dwThreadId);
[DllImport("user32.dll", CharSet = CharSet.Auto, SetLastError = true)]
private static extern IntPtr CallNextHookEx(IntPtr hhk, int nCode, IntPtr wParam, IntPtr lParam);
private void ThisAddIn_Startup(object sender, System.EventArgs e)
{
hookId = SetHook(procedure);
}
private void ThisAddIn_Shutdown(object sender, System.EventArgs e)
{
UnhookWindowsHookEx(hookId);
}
private static IntPtr SetHook(HookProcedure procedure)
{
using (Process process = Process.GetCurrentProcess())
using (ProcessModule module = process.MainModule)
return SetWindowsHookEx(WH_KEYBOARD_LL, procedure, GetModuleHandle(module.ModuleName), 0);
}
private static IntPtr HookCallback(int nCode, IntPtr wParam, IntPtr lParam)
{
if (nCode >= 0 && wParam == (IntPtr)WM_KEYDOWN)
{
int pointerCode = Marshal.ReadInt32(lParam);
string pressedKey = ((Keys)pointerCode).ToString();
//Do some sort of processing on key press
var thread = new Thread(() => { MessageBox.Show(pressedKey); });
thread.Start();
}
return CallNextHookEx(hookId, nCode, wParam, lParam);
}
private void InternalStartup()
{
this.Startup += new System.EventHandler(ThisAddIn_Startup);
this.Shutdown += new System.EventHandler(ThisAddIn_Shutdown);
}
}
You might try to use the Excel WebBrowser Control instead of the System.Windows.Forms WebBrowser; it handles special key forwarding as TAB, DEL, CTRL+V, etc.
For that change the WebBrowser contructor from
new System.Windows.Forms.WebBrowser();
to
new Microsoft.Office.Tools.Excel.Controls.WebBrowser();
You would need to add references to your project: Project/Add Reference/Extensions select Microsoft.Tools.Outlook & Microsoft.Tools.Outlook.v4.0.Utilities

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