We Keep Coding

C# Detect Keystrokes and Send to Background Windows

I've looked around for six hours today in search of a method to complete the task I'm looking to accomplish. However with little luck every method I've tried has come out not working.
So the program I'm working on is a multiboxing application for video games. Essentially I want to have my created application running in the background. The user will check on checkbox's to state which keys they want to be captured, so not every key is being captured. Then while they are playing the main game, the application will send the keys that are checked to the games running in the background.
I've tried global hotkeys however never could get more than one key working. I've also tried to hook keys but for some reason, couldn't get that functional. I also dabbled into sendmessage with little luck there either.
Was just curious if anyone else had some ideas for going about doing this. To give an example of another program that does this same thing would be HotKeyNet, KeyClone, and ISboxer. I know there are more out there but that gives you an idea of what I'm trying to do with my application.

Alright, after quite a bit of research into different methods for sending keystrokes and reading keystrokes. I finally was able to splice to different types of coding together to provide the results I was looking for.
I'm posting up the answer, so anyone that is looking for the answer to this question later down the road has it available to them.
My two references for splicing this code together are the following:
http://www.codeproject.com/Articles/19004/A-Simple-C-Global-Low-Level-Keyboard-Hook
Send combination of keystrokes to background window
I used the global low level hook and postmessage for sending keystrokes to the background application.
So first you will need to follow the instructions from the first
link, to get the starting code working.
Download the working source code from link one, and use the
globalKeyboardHook.cs in your application.
Then in references place the following:
using System.Runtime.InteropServices; //Grabs for your DLLs
using Utilities; //Grabs from the file you added to your application.
Now you will want to place the following code in your class:
globalKeyboardHook gkh = new globalKeyboardHook();
[DllImport("user32.dll")] //Used for sending keystrokes to new window.
public static extern IntPtr PostMessage(IntPtr hWnd, uint Msg, IntPtr wParam, IntPtr lParam);
[DllImport("user32.dll", EntryPoint = "FindWindow", CharSet = CharSet.Ansi)] //Used to find the window to send keystrokes to.
public static extern IntPtr FindWindow(string className, string windowName);
Now go ahead place your keystrokes you want to be grabbed this I
found is best in Form1_Loaded:
gkh.HookedKeys.Add(Keys.A);//This collects the A Key.
gkh.HookedKeys.Add(Keys.B);//This collects the B Key.
gkh.HookedKeys.Add(Keys.C);//This collects the C Key.
gkh.KeyDown += new KeyEventHandler(gkh_KeyDown); //Event for pressing the key down.
gkh.KeyUp += new KeyEventHandler(gkh_KeyUp); //Event for the release of key.
After that you will want to go ahead and place in the following in
your code as well:
void gkh_KeyUp(object sender, KeyEventArgs e) //What happens on key release.
{
lstLog.Items.Add("Up\t" + e.KeyCode.ToString());
e.Handled = false; //Setting this to true will cause the global hotkeys to block all outgoing keystrokes.
}
void gkh_KeyDown(object sender, KeyEventArgs e) //What happens on key press.
{
lstLog.Items.Add("Down\t" + e.KeyCode.ToString());
e.Handled = false;
}
Once that is in place just put this little bit in the gkh_KeyDown to
get your keystrokes to send to another window of your choosing:
const uint WM_KEYDOWN = 0x100;
IntPtr hWnd = FindWindow(null, "Example1"); //Find window Example1 for application.
switch (e.KeyCode)
{
case Keys.A: //Makes it so it only sends that key when it's pressed and no other keys.
if(chkA.Checked == true)
{
PostMessage(hWnd, WM_KEYDOWN, (IntPtr)(Keys.A), IntPtr.Zero); //Sends to key A to new window assigned hWnd which equals Example1.
}
break;
}
}
The code that I have provided is setup so people can use checkbox's to tell the program which keys they want to send over to the second application.
If you have any questions regarding to this post just let me know, and I will do my best to walk you through the process. Hope this helps someone out later down the road.

My suggestion is to go with "mapped memory" (in operating system concepts: shared memory)
First process creates (may be your check state program) creates a mapped memory and writes values to it.
All other game process reads the value from memory map created by first process.
Here is a very nice example regarding how to do it.
https://msdn.microsoft.com/en-us/library/dd267552(v=vs.110).aspx

C# Using PostMessage

I'm trying to send a key to an application. I tested the Handlewindow value used breakpoints to understand what I'm doing wirong but i cant find a solution. To be more detailed, its a little game and when I activate the chatbar ingame, the key I want to send will be written there, but I want to make it functionaly when I am playing to use the commands. The game doesnt have a guard or some protections.
Here is my code:
[DllImport("user32.dll")]
static extern bool PostMessage(IntPtr hWnd, uint Msg, int wParam, int lParam);
const uint WM_KEYDOWN = 0x0100;
private void button1_Click(object sender, EventArgs e)
{
string pName = textBox1.Text;
//Get Processes
Process[] processes = Process.GetProcessesByName(pName);
//Main part
foreach (Process p in processes)
if (p.ProcessName == (string)pName)
{
PostMessage(p.MainWindowHandle, WM_KEYDOWN, (int)Keys.W, 0);
}
}
Like I said, it can be sent 1000000 times successfully but nothing happens.
Is there another way how I can send keys to an Windows application that works minimized or even hidden? It should be only send to my app.

If i understand correctly, you want to send keys to a game.
In this case i think that the game is not fetching the keys from the Windows Message queue, it is probably reading the keyboard status directly using DirectX or similar ways.
See this similar question:
Send Key Strokes to Games

You can't fake messages like this and expect it to work reliably - all you are doing is sending a message, nothing fancy.
What this means is that if the target program tests for input in a different way (for example by directly checking the key state, reacting to different messages or just using a completely different mechanism) the target program at best may just completely ignore your input and at worst get totally confused.
Use the SendInput function instead (I'm not sure if this exposed as part of the .Net framework or not).
Some interesting blog articles which are fairly relevant:
You can't simulate keyboard input with PostMessage
Simulating input via WM_CHAR messages may fake out the recipient but it won't fake out the input system

Just note that the correct import of PostMessage is:
[DllImport("user32.dll")]
static extern bool PostMessage(HandleRef hWnd, uint Msg, IntPtr wParam, IntPtr lParam);
Sending the keys like you are doing might not work, but you can use spy++ to capture the actual messages that are being posted to the application by windows and use those.
https://learn.microsoft.com/en-us/visualstudio/debugger/introducing-spy-increment?view=vs-2022

Often programmers will react to KeyUp events rather than down; did you try sending WM_KEYUP?

You should be using SendInput to simulate input into another window.
See this blog post for more details.

Alternative to GetWindowModuleFileName to get other processes ApplicationFileName?

In order to get the application name of the foreground Window (or the name of application file) I want to use GetActiveWindow with GetWindowModuleFileName.
I found a similar question relating to GetWindowText here
That implementation of GetWindowText works fine, but GetWindowModuleFileName only returns a value for visual studio (when I click inside the devenv) for all other applications it stays blank.
Any hint how I can find out what goes wrong? Might this have to do with permission/security of my application querying the applicationfilename of another process?
EDIT: http://support.microsoft.com/?id=228469 looks like this doesn't work under Win >=XP
Any alternatives how to get the application file name?

In order to get the application name of the foreground Window (or the name of application file) I want to use GetActiveWindow with GetWindowModuleFileName.
... querying the applicationfilename of another process ...
In my opinion your problem with use of GetActiveWindow() function. It is used for gathering information from the calling thread/process only. If calling thread is inactive GetActiveWindow return 0;
From MSDN:
GetActiveWindow Retrieves the window handle to the active window attached to the calling thread's message queue.
Try to use GetForegroundWindow() function instead of GetActiveWindow()

By chance do you have UAC turned off?
Starting with Vista, if your code touches an HWND in another process, your process needs to be run at the same privilege level.
In other words, if the window is hosted in a process running as administrator, your app must also run as administrator.

I found a workaround using this:
[DllImport("user32.dll", SetLastError = true)]
static extern uint GetWindowThreadProcessId(IntPtr hWnd, out uint lpdwProcessId);
IntPtr handle = IntPtr.Zero;
handle = GetForegroundWindow();
uint processId;
if (GetWindowThreadProcessId(handle, out processId) > 0)
{
Console.WriteLine(Process.GetProcessById((int)processId).MainModule.FileName);
}

Can I disable window autoplay function programatically with C#/.NET?

Does anybody know a way to deactivate the autoplay function of windows using c#/.NET?

A little summary, for all the others looking for a good way to disable/supress autoplay.
So far I've found 3 methods to disable autoplay programatically:
Intercepting the QueryCancelAutoPlay message
Using the Registry
Implementing the COM Interface IQueryCancelAutoPlay
In the end I chose the 3rd method and used the IQueryCancelAutoPlay interface because the others had some signifcant disadvantages:
The first method
(QueryCancelAutoPlay) was only able
to suppress autoplay if the
application window was in the foreground, cause only the foreground window receives the message
Configuring autoplay in the registry worked even if the application window was in the background. The downside: It required a restart of the currently running explorer.exe to take effect...so this was no solution to temporarily disable autoplay.
Examples for the implementation
1. QueryCancelAutoPlay
Suppressing AutoRun Programmatically (MSDN article)
CodeProject: Preventing a CD from Auto-Playing
Canceling AutoPlay from C#
Note: If your application is using a dialog box you need to call SetWindowLong (signature) instead of just returning false. See here for more details)
2. Registry
Using the registry you can disables AutoRun for specified drive letters (NoDriveAutoRun) or for a class of drives (NoDriveTypeAutoRun)
Using the Registry to Disable AutoRun (MSDN article)
How to Enable / Disable Autorun for a Drive (using Registry)
Windows 7 AutoPlay Enable | Disable
3. IQueryCancelAutoPlay
Reference for the IQueryCancelAutoPlay interface on MSDN
IQueryCancelAutoPlay only called once? (Example implementatio, also read comments)
AutoPlayController (another implementation, not tested)
Some other links:
Enabling and Disabling AutoRun (MSDN article)
Autoplay in Windows XP: Automatically Detect and React to New Devices on a System (an old but extensive article on Autoplay)

RegisterWindowMessage is a Win32 API call. So you will need to use PInvoke to make it work..
using System.Runtime.InteropServices;
class Win32Call
{
[DllImport("user32.dll")]
public static extern int RegisterWindowMessage(String strMessage);
}
// In your application you will call
Win32Call.RegisterWindowMessage("QueryCancelAutoPlay");
From here (The Experts-Exchange link at the top). There is additional help on that site with some more examples that may be a little more comprehensive than the above. The above does however solve the problem.

Some additional links that might be helpful:
Preventing a CD from
Auto-Playing shows some example
vb.net code, showing the usage of
"QueryCancelAutoPlay" on CodeProject.
Enabling and Disabling AutoRun on MSDN.

Try this code work for me :) For more info check out this reference link : http://www.pinvoke.net/default.aspx/user32.registerwindowmessage
using System.Runtime.InteropServices;
//provide a private internal message id
private UInt32 queryCancelAutoPlay = 0;
[DllImport("user32.dll", SetLastError=true, CharSet=CharSet.Auto)]
static extern uint RegisterWindowMessage(string lpString);
/* only needed if your application is using a dialog box and needs to
* respond to a "QueryCancelAutoPlay" message, it cannot simply return TRUE or FALSE.
[DllImport("user32.dll")]
static extern int SetWindowLong(IntPtr hWnd, int nIndex, int dwNewLong);
*/
protected override void WndProc(ref Message m)
{
//calling the base first is important, otherwise the values you set later will be lost
base.WndProc (ref m);
//if the QueryCancelAutoPlay message id has not been registered...
if (queryCancelAutoPlay == 0)
queryCancelAutoPlay = RegisterWindowMessage("QueryCancelAutoPlay");
//if the window message id equals the QueryCancelAutoPlay message id
if ((UInt32)m.Msg == queryCancelAutoPlay)
{
/* only needed if your application is using a dialog box and needs to
* respond to a "QueryCancelAutoPlay" message, it cannot simply return TRUE or FALSE.
SetWindowLong(this.Handle, 0, 1);
*/
m.Result = (IntPtr)1;
}
} //WndProc

Win32 API call through a serivce

I have develop a program which turns off the monitor by standard sendmassage api call:
public int WM_SYSCOMMAND = 0x0112;
public int SC_MONITORPOWER = 0xF170;
const int HWND_BROADCAST = 0xFFFF;
SendMessage(-1, WM_SYSCOMMAND, SC_MONITORPOWER, 2);
My question is I dont want it to be a windows form, but a windows service instead... The sendmessage doesnt not in a windows service. How can I get it to work?
Regards,
Christian

Using HWND_BROADCAST / -1 is so wrong I don't even know where to begin, see this blog post for details
If for whatever reason you can't create a window, you could try to PInvoke the DefWindowProc function directly
Are you even sure it is possible to do this from a service? You might have to call CreateProcessAsUser and start a helper app

You can use GetDesktopWindow method and send the message to that window. Or you can use FindWindow and FindWindowEx methods to get the currently active window and send message there. Or you can add a reference to System.Windows.Forms in your service and instantiate a Form object and use that handle to send the message.