Prevent closing the Application by Taskmanager (or something similar) - c#

I'm coding an AntiCheat Module for an own little Projekt. It's coded in C#, but it wouldn't matter, if the solution is in C++ (As long, as it's working).
The Problem is, my program runs in the Background, you can't see it. For that I used this Code:
[DllImport("kernel32.dll")]
static extern IntPtr GetConsoleWindow();
[DllImport("user32.dll")]
static extern bool ShowWindow(IntPtr hWnd, int nCmdShow);
const int SW_HIDE = 0;
const int SW_SHOW = 5;
var handle = GetConsoleWindow();
ShowWindow(handle, SW_HIDE);
But what is, if the User is detecting this program and simply close it? All I need is an Event, that appears when a User is closing it via Taskmanager (or something similar), that the Game can be closed and no cheats can apply & take effect to the game.
Do you have any plan? Or just something what matches my requirements, so that the AntiCheat is working?
As I said, if it's in C++, it doesn't matter.

Related

is there easy way to check some process is activated?

I sent a WM_ACTIVE message using postmessage api to some programs.
When a program is deactivated, sending a message does not actually activate the window, but the program thinks it is active. ( It actually succeeded. )
However, I think it is very inefficient to send postmessage regularly.
If I want to check the WM_ACTIVE value of the program and it is inactivated, I try to send a WM_ACTIVE message again using the POSTMESSAGE API to confuse the program itself with being active, but I can't think of a way. Although there is an idea that hooking would be easy to use, C# did not support other types of global hooking except for the keyboard and mouse.
Can anyone come up with any other ideas? please help me.
To check if a process is focused you should use GetForegroundWindow to get the focused window handle and then use GetWindowThreadProcessId to get the process from that window handle:
[DllImport("user32.dll")]
private static extern IntPtr GetForegroundWindow();
[DllImport("user32.dll")]
static extern uint GetWindowThreadProcessId(int hWnd, out int ProcessId);
IntPtr focusedWindow = GetForegroundWindow(); //get the focused window
int focusedProcessID = 0;
GetWindowThreadProcessID(focusedWindow, out focusedProcessID); //get it's process id
Process focusedProcess = Process.GetProcessById(focusedProcessID);//get the focused process
Console.WriteLine("Current Focused Process:" + focusedProcess.ProcessName);

How to make Console App listen for keypresses from other processes?

I'm new to C# programming and I'm attempting to write a Console App that will run in the background and perform an action when a key is pressed (ideally I would like to know how to do this for any key but, if that's not possible, then a specific key).
Here's an idea of what I want (please excuse and feel free to correct any bad coding as I'm just starting out).
public static void Main(string[] args)
{
while(true)
{
ConsoleKeyInfo cki = Console.ReadKey();
if( cki.Key == ConsoleKey.R )
{
Console.WriteLine("Run me");
}
}
}
The above seems to work but only if the Console App is in focus. I would like it to happen even if the app isn't in focus.
I've done some research and read about registering 'hotkeys' but also read that this is dangerous in case another application is requiring that key?
I've also read similar questions on here but they seem to deal with Windows Forms and not just Console Apps.
Can anyone help shed any light on this?
You need to use
[DllImport("user32", SetLastError = true)]
private static extern bool RegisterHotKey(IntPtr hWnd, int id, uint fsModifiers, uint vk);
[DllImport("user32", SetLastError = true)]
private static extern bool UnregisterHotKey(IntPtr hWnd, int id);
But to make it work from console you'll need to create hidden form that will handle messages for you. Check out this class. It does exactly what you want.

Showing Outlook instead of displaying a message in C#.Net [duplicate]

We only want one instance of our app running at any one time. So on start up it looks to see if the app is running and if it is, it calls SetForegroundWindow on the Main Window.
This is all good and well ... for the most part..
When our app starts up it will show a Splash screen and a Logon form. Both of these forms have ShowInTaskBar = false.
Because of this, if you try to start up another copy of the app when the Logon form is showing, that Logon form is not brought to the front!
Especially as the user cant see anything in the taskbar as well, all they figure is that the app is duff and cannot start. There is no indication that there is another instance running.
Is there any way around this problem?
Well, code is here. Even if the ShowInTaskBar is false, you should be able to bring it to the front.
[DllImport("USER32.DLL", CharSet = CharSet.Unicode)]
public static extern IntPtr FindWindow(String lpClassName, String lpWindowName);
[DllImport("USER32.DLL")]
public static extern bool SetForegroundWindow(IntPtr hWnd);
public static void bringToFront(string title) {
// Get a handle to the Calculator application.
IntPtr handle = FindWindow(null, title);
// Verify that Calculator is a running process.
if (handle == IntPtr.Zero) {
return;
}
// Make Calculator the foreground application
SetForegroundWindow(handle);
}
Note: you should FindWindow using the form's class and not by name as the splash screen forms sometimes do not have titles or even the controlbox. Use Spy++ to dig deeper.
Use FindWindow on splash. I think this is what you want to do - bring the splash screen in front while loading of the main form.
I think this is the better solution because its restores from minimized state:
public static class WindowHelper
{
public static void BringProcessToFront(Process process)
{
IntPtr handle = process.MainWindowHandle;
if (IsIconic(handle))
{
ShowWindow(handle, SW_RESTORE);
}
SetForegroundWindow(handle);
}
const int SW_RESTORE = 9;
[System.Runtime.InteropServices.DllImport("User32.dll")]
private static extern bool SetForegroundWindow(IntPtr handle);
[System.Runtime.InteropServices.DllImport("User32.dll")]
private static extern bool ShowWindow(IntPtr handle, int nCmdShow);
[System.Runtime.InteropServices.DllImport("User32.dll")]
private static extern bool IsIconic(IntPtr handle);
}
Simple call:
WindowHelper.BringProcessToFront(process);
FindWindow(null, title);
Will find the first window that matches the query. This may lead to unexpected behavior if another window uses the same title.
Although the chances of this to happen may seem rare or impossible (single instance application) this can easily occur. The windows explorer for instance uses the name of the selected directory as window title (although invisible). Now if the window title is a common term or matches the name of the application directory this can be an issue.

Ensuring a single instance of an application using WINAPI?

Got curious when someone down-voted this code as a solution to running only a single instance of an application without stating why they did so.
int hWnd = FindWindow(null, "My Application Title");
if (hWnd > 0) //If found
{
Process.GetCurrentProcess().WaitForExit(600);
try
{
SetForegroundWindow(hWnd); //Activate it
ShowWindow(hWnd, 9);
Process.GetCurrentProcess().Kill();
}
catch (Exception ex)
{
//write to log
}
}
//Import the FindWindow API to find our window
[DllImport("User32.dll")]
public static extern int FindWindow(String ClassName, String WindowName);
//Import the SetForeground API to activate it
[DllImport("User32.dll")]
public static extern IntPtr SetForegroundWindow(int hWnd);
//Import the ShowWindow API to show it
[DllImport("User32.dll")]
public static extern bool ShowWindow(int hWnd, int nCmdShow);
Could someone be kind as to explain the drawbacks of this method to me? Thanks.
Because if the application is starting twice (accidental clicking), there is a small window of time where the test will fail. Both instances could be starting but neither has created a window yet.
The drawbacks as far as I can see are that it is overly complicated for what should be a simple solution. You do not need to crack into the windows api to force a single instance of an api. I would guess that is why you got downvoted.
If you follow the links in the Uwe's answer, you will see that you can remain in managed code, which should be your default unless there is some reason you MUST dig a little deeper.

Send Keystrokes to a program even if its in background using c#

I wanna send key stroke to a program even if it is running in background. But I can do this only for NOTEPAD like this,
[DllImport("user32.dll")]
protected static extern byte VkKeyScan(char ch);
[DllImport("user32.dll", SetLastError = true)]
protected static extern IntPtr FindWindowEx(IntPtr hwndParent, IntPtr hwndChildAfter, string lpszClass, string lpszWindow);
[DllImport("User32.Dll", EntryPoint = "PostMessageA")]
protected static extern bool PostMessage(IntPtr hWnd, uint msg, int wParam, int lParam);
char Key = // key value to send
IntPtr hWnd = FindWindowEx(_handle, IntPtr.Zero, "edit", null); // _handle is the windows handle of the program (here its notepad)
PostMessage(hWnd, WM_KEYDOWN, VkKeyScan(Key), 0);
But for all other applications I can't send keystrokes if its in background. Since I don't know the lpszClass of that program (I think this is the userControl name of the typing area in that program. For NotePad it is "edit". I found this surfing internet).
For all other applications what I'm doing is, get the application to foreground, then send the key, then again get my program foreground. I need my program to be run as foreground always.
[DllImport("USER32.DLL")]
public static extern bool SetForegroundWindow(IntPtr hWnd);
SetForegroundWindow(_handle); // _handle is the windows handle of the program
System.Threading.Thread.Sleep(50); // Waiting few milliseconds till application coming to foreground.
wsh.SendKeys(Key.ToString(), ref wait); // wsh is WshShellClass wsh= new WshShellClass();
SetForegroundWindow(_mainHandle); // _mainHandle is the windows handle of my application
But this way is not working. some keys getting missed and the program foreground->background->foregound->background...... like its dancing...
How to send keys to other applications if its running in background.
or are there any way/source to find the lpszClass of a program ?
Sorry if I have missed any required information. this is a large application. I have posted only required parts here. If someone needs any additional information, pls ask.
I think you'll need to have the background program install a low-level keyboard hook via the win32 function SetWindowsHookEx().
Here's the MSDN documentation for SetWindowsHookEX()
http://msdn.microsoft.com/en-us/library/ms644990(v=vs.85).aspx
And here's the KB article on how to do it from C#
http://support.microsoft.com/kb/318804
This article goes into some detail, too: http://www.codeguru.com/columns/vb/article.php/c4829
I expect your app will get caught by various spyware/anti-virus software as a keyboard logger, though.
Good luck.
You may be able to figure out the lpszClass of the program using an inspection tool such as WinSpy++. It gives you a crosshair that you can drag and position over the desired control. This was able to easily provide me with the "edit" class name for notepad.
If things aren't working, click the "More>>" button in the lower right of WinSpy++, then click the "Locate" button to view the control hierarchy; you may need to post the WM_KEYDOWN message to one of the parent or child controls instead.

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