I made a little DLL in C++ that I inject into the GTA San Andreas game. Now I want to create hotkeys that work in-game. Like when I press F10 it sets the player's health to maximum. I already know how to set the health and all but I don't know how to make hotkeys.
Here is some code I found but it isn't for DLL usage I suppose:
bool customKeyHook(HWND hWnd, UINT uMsg ,WPARAM wParam, LPARAM lParam)
{
switch(wParam)
{
case VK_F10:
*playerHP = 200;
return true;
}
}
Create a Thread with CreateThread an then create an infinite loop and wait for the keypress:
if (GetAsyncKeyState(VK_F10) & 1)
{
}
Related
I am working a program to simulate keyboard and mouse clicks programmatically. It need to send the clicks to a target window handle (ex: notepad edit control). I am getting the handle of notepad window and generating generating WM_KEYDOWN, WM_SYSKEYDOWN, WM_KEYUP, WM_SYSKEYUP messages for that window. The events are stored in queue, and later on played using a WH_JOURNALPLAYBACK hook.
For the code snippet below, the target hwnd in the playback proc though set correctly, messages never reach to the target handle. If I bring the notepad to foreground, it does receive the messages.
I am not sure why WH_JOURNALPLAYBACK ignores the handle parameter. I would have liked to generate a series of automation messages for various handles and played it back so that even without bringing the window into focus we can send keyboard and mouse events.
Please let me know
if messages to various target handles can be sent using a journal
playback hook
why in code below hwnd is ignored
..
#include <queue>
#include <iostream>
#include <windows.h>
using std::cout;
using std::endl;
using std::error;
struct Event
{
UINT msg;
UINT wparam;
UINT lparam;
HWND hwnd;
Event(UINT m, UINT wp, UINT lp, HWND h)
:msg(m),
wparam(wp),
lparam(lp),
hwnd(h)
{}
};
HHOOK jhook= NULL;
std::queue<Event> events;
bool gotoNextMsg = false;
LRESULT CALLBACK JournalPlaybackProc(int code, WPARAM wParam, LPARAM lParam)
{
switch( code )
{
case HC_SKIP:
cout<<"skip: "<<endl;
if(!events.empty())
{
events.pop();
}
break;
case HC_GETNEXT:
{
cout<<"next: "<<events.size()<<endl;
gotoNextMsg = true;
EVENTMSG * evm = (EVENTMSG*) lParam;
Event e = events.front();
switch(e.msg)
{
case WM_KEYDOWN:
cout<<"WM_KEYDOWN"<<endl;
break;
case WM_KEYUP:
cout<<"WM_KEYUP"<<endl;
break;
case WM_SYSKEYDOWN:
cout<<"WM_SYSKEYDOWN"<<endl;
break;
case WM_SYSKEYUP:
cout<<"WM_SYSKEYUP"<<endl;
break;
}
cout<<"handle: "<<e.hwnd<<endl;
cout<<"handle1:"<<evm->hwnd<<endl;
evm->message = e.msg;
evm->paramL = e.wparam;
evm->paramH = e.lparam;
evm->hwnd = e.hwnd;
evm->time = ::GetTickCount();
}
break;
default:
if( code < 0 )
::CallNextHookEx(jhook, code, wParam, lParam);
break;
}
if(events.empty())
{
cout<<"uinstalled"<<endl;
::UnhookWindowsHookEx(jhook);
::PostMessage(NULL, WM_USER+100, 0, 0);
}
return 0;
}
A journal hook injects events into the system message queue. For keyboard and mouse messages, the system dispatches them to the current focused window, same as if the user had input them manually. The HWND you specify in the event is not used, it gets replaced during dispatching.
And if you consider that a recorded journal can be played multiple times, and its data can persist across application instances and even reboots, and that HWNDs can be reused for different things over time, it should make sense why a journal playback cannot make use of an event's HWND even if the system message queue were not involved.
So, you cannot use WH_JOURNALPLAYBACK to target a specific window that is not in the foreground. You would have to send the recorded messages yourself. But be aware of some caveats that Raymond Chen has blogged about:
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
I am trying to write a simple global keyboard hook program to redirect some keys. For example, when the program is executed, I press 'a' on the keyboard, the program can disable it and simulate a 'b' click. I do not need a graphic ui, just a console is enough (keep it running)
My plan is to use global hook to catch the key input, and then use keybd_event to simulate the keyboard. But I have some problems.
The first problem is that the program can correctly block 'A' but if I hit 'A' on the keyboard once, the printf in the callback function is executed twice, as well as the keybd_event. So if i open a txt file, i click 'A' once, there are two 'B's input. why is that?
The second question is that why the hook using of WH_KEYBOARD_LL can work on other process without a dll? I thought that we had to use a dll to make a global hook until I wrote this example...
#include "stdafx.h"
#include <Windows.h>
#define _WIN32_WINNT 0x050
LRESULT CALLBACK LowLevelKeyboardProc(int nCode, WPARAM wParam, LPARAM lParam)
{
BOOL fEatKeystroke = FALSE;
if (nCode == HC_ACTION)
{
switch (wParam)
{
case WM_KEYDOWN:
case WM_SYSKEYDOWN:
case WM_KEYUP:
case WM_SYSKEYUP:
PKBDLLHOOKSTRUCT p = (PKBDLLHOOKSTRUCT)lParam;
if (fEatKeystroke = (p->vkCode == 0x41)) { //redirect a to b
printf("Hello a\n");
keybd_event('B', 0, 0, 0);
keybd_event('B', 0, KEYEVENTF_KEYUP, 0);
break;
}
break;
}
}
return(fEatKeystroke ? 1 : CallNextHookEx(NULL, nCode, wParam, lParam));
}
int main()
{
// Install the low-level keyboard & mouse hooks
HHOOK hhkLowLevelKybd = SetWindowsHookEx(WH_KEYBOARD_LL, LowLevelKeyboardProc, 0, 0);
// Keep this app running until we're told to stop
MSG msg;
while (!GetMessage(&msg, NULL, NULL, NULL)) { //this while loop keeps the hook
TranslateMessage(&msg);
DispatchMessage(&msg);
}
UnhookWindowsHookEx(hhkLowLevelKybd);
return(0);
}
Many thanks!
Your callback function execute twice because of WM_KEYDOWN and WM_KEYUP.
When you down a key of your keyboard, windows calls the callback function with WM_KEYDOWN message and when you release the key, windows calls the callback function with WM_KEYUP message. That's why your callback function execute twice.
You should change your switch statement to this:
switch (wParam)
{
case WM_KEYDOWN:
case WM_SYSKEYDOWN:
case WM_KEYUP:
case WM_SYSKEYUP:
PKBDLLHOOKSTRUCT p = (PKBDLLHOOKSTRUCT)lParam;
if (fEatKeystroke = (p->vkCode == 0x41)) //redirect a to b
{
printf("Hello a\n");
if ( (wParam == WM_KEYDOWN) || (wParam == WM_SYSKEYDOWN) ) // Keydown
{
keybd_event('B', 0, 0, 0);
}
else if ( (wParam == WM_KEYUP) || (wParam == WM_SYSKEYUP) ) // Keyup
{
keybd_event('B', 0, KEYEVENTF_KEYUP, 0);
}
break;
}
break;
}
About your second question, I think you have already got from #Ivan Danilov answer.
First one is easy. You get one for key down and another for key up. :)
As for the why it can work without a DLL - that's because it is a global hook. Unlike thread-specific ones it is executed in your own process, not in the process where keyboard event happened. It is done via message sending to the thread which has installed the hook - that's precisely why you need message loop here. Without it your hook can't be ran as there would be no one to listen for incoming messages.
The DLL is required for thread-specific hooks because they're called in the context of another process. For this to work, your DLL should be injected into that process. It is just not the case here.
I have run your code but nothing happend? What wrong with me?
Base on msdn that WH_KEYBOARD_LL message is "Global only" It mean more than that.
The system calls this function .every time a new keyboard input event is about to be posted into a thread input queue.
This message is special case. You also need an DLL to make a real global hook for other message.
I want to put inside a software the necessary codes for it to disable Windows (Xp, Vista, specially 7 and sucessors) hotkeys that could allow the user to get away from the software.
Details:
The commands must be valid only while the software is running; when its not running, Windows hotkeys must be enabled (so: if the user starts the software, the hotkeys are disable; if he closes it, must be re-enabled).
I don't want to disable all windows hotkeys (some key hotkeys such as ctrl+alt+del must still be operational), so solutions such as some sort of windows configuration that disable all hotkeys are useless for me. I must be capable of specifically select which hotkeys I want to continue working and which I don't.
The "hotkey" nickname includes the Windows button.
The code must be either using C++ or Windows functions.
Preferetially without requiering to terminate explorer.exe.
I did look at a post here in stackoverflow that had a very similiar case as mine (Prevent users from quitting a windows application via system hotkeys), but as far as I understood nether of the solutions presented were applicable to my specific situation, and I didn't find anything in the web as well.
Ok, I got how to do it. The code is able to create a sistem-wide hook without DLL using a low level keyboard hook. Here is the code (better that explaining)(using Qt):
//Installing the hook
SWH_return = SetWindowsHookEx(WH_KEYBOARD_LL,LowLevelKeyboardProc,GetModuleHandle(NULL),0);
if (SWH_return != NULL)
qDebug() << "Hook true";
else
qDebug() << "Hook false";
//Uninstalling the hook
bool teste = false;
teste = UnhookWindowsHookEx(SWH_return);
if (teste)
qDebug() << "Unhook: true";
else
qDebug() << "Unhook: false";
//The function responsible for detecting the keystrokes
LRESULT CALLBACK LowLevelKeyboardProc(int nCode, WPARAM wParam, LPARAM lParam)
{
if (nCode < 0)
return CallNextHookEx(NULL, nCode, wParam, lParam);
tagKBDLLHOOKSTRUCT *str = (tagKBDLLHOOKSTRUCT *)lParam;
switch(str->flags)
{
case (LLKHF_ALTDOWN):
qDebug() << "ALT";
delete str;
return 1;
}
if (wParam == WM_KEYDOWN)
{
switch (str->vkCode)
{
case VK_RWIN:
case VK_LWIN:
case VK_LCONTROL:
case VK_RCONTROL:
case VK_APPS:
case VK_SLEEP:
case VK_MENU:
qDebug() << "SPECIAL PRESS";
delete str;
return 1;
}
}
return CallNextHookEx(NULL, nCode, wParam, lParam);
}
This last function don't need any declaration in the .h or in the .cpp file. It blocks inputs of Ctrl, Windows Key and Alt. The other two must be placed respectively in the functions where the user wants to begin the key disabling and when he want it to stop.
Thanks,
Momergil.
RegisterHotKey is also globally disable hotkey for all applications except where RegisterHotKey function call is made.
RegisterHotKey(GetSafeHwnd(), 100, 0,VK_F5); //F5 works only in our application
I have a little console application that has an embedded v8 engine, and I would like to add a hook to register key events. This all worked before when I was using Qt and QtScript, but I am porting it all over to straight C++ in VC++ 2008. The application compiles and runs, but the hook is never called, here is the relevant code:
In main()
HWND hwndC = GetConsoleWindow() ;
HINSTANCE hInst = (HINSTANCE)GetWindowLong( hwndC, GWL_HINSTANCE );
if (SetWindowsHookEx(WH_KEYBOARD_LL, HookProc, hInst, NULL) == 0) {
printf("Failed to set hook\n");
} else {
printf("Hook established\n");
}
g->RunScript(argc,argv);
And the proc:
LRESULT CALLBACK HookProc(int nCode, WPARAM wParam, LPARAM lParam)
{
printf("HookProc called\n");
PKBDLLHOOKSTRUCT p = (PKBDLLHOOKSTRUCT) (lParam);
if (wParam == WM_KEYDOWN) {
keyDown(p,g);
} else if (wParam == WM_KEYUP) {
keyUp(p,g);
}
fflush(stdout);
return CallNextHookEx(NULL, nCode, wParam, lParam);
}
This is essentially an expansion on shell.cc from the v8 sample code. I wonder if it is somehow blocking? I admit to not really knowing what I am doing here, just playing around and learning but this one has me stumped.
Inside of keyDown say, I have something like this:
v8::Handle<v8::String> callback_name = v8::String::New("onKeyDown");
v8::Handle<v8::Value> callback_val = g->_context->Global()->Get(callback_name);
if (!callback_val->IsFunction()) {
printf("No onKeyDown handler found\n");
return;
}
v8::Handle<v8::Function> callback = v8::Handle<v8::Function>::Cast(callback_val);
const int argc = 1;
v8::Handle<v8::Value> argv[argc] = { v8::Int32::New(char(p->vkCode)) };
printf("Calling onKeyDown\n");
v8::Handle<v8::Value> result = callback->Call(g->_context->Global(), argc, argv);
Some of this may actually not work in the end, but it just never gets called, when I run the program, and define: onKeyDown = function(key) {...}; I can see that onKeyDown is working just fine, I can use all of my bound c++ method etc from JS, so this thing is just driving me batty.
Any help, maybe pointers to some educational materials would be much appreciated.
Just to be clear, this function in c: LRESULT CALLBACK HookProc(int nCode, WPARAM wParam, LPARAM lParam) is never getting called, or never seeing a printf, and the output at the start says: Hook established, so windows is reporting the hook is established.
/Jason
A low-level hook, like WH_KEYBOARD_LL requires that your application pumps a message loop. That's the only way that Windows can break into your thread and make the call to the HookProc callback you registered.
A console mode app doesn't pump a message loop like regular Windows GUI apps do. Judging from your snippet, it isn't going to be easy to add one either. You'll need to create a thread.
Maybe this function will be of help to you?
GetAsyncKeyState
I have a win 32 application written in c++ which sets the low level keyboard hook. now i want to sendInput to any app like word / notepad. how do i do this?
i have already done enough of using findwindow / sendmessage. for all these, i need to know edit controls. finding the edit control is very difficult.
since SendInput works for any windows application, i want to use it. the problem is i get a call to my callback function with the pressed key.
for e.g i pressed A and i want to send U+0BAF unicode character to the active applciation windows. in this case, assume it is notepad.
the problem is i get two characters U+0BAF and A in the notepad.
A is being sent because i am calling CallNextHookEx( NULL, nCode, wParam, lParam);
if i return 1 after sendInput, then nothing is sent to notepad.
any suggestion?
If I understood your problem correctly, you should ignore "injected" key events in your hook procedure, like this:
LRESULT CALLBACK
hook_proc( int code, WPARAM wParam, LPARAM lParam )
{
KBDLLHOOKSTRUCT* kbd = (KBDLLHOOKSTRUCT*)lParam;
// Ignore injected events
if (code < 0 || (kbd->flags & LLKHF_INJECTED)) {
return CallNextHookEx(kbdhook, code, wParam, lParam);
}
...
Update: additionally, you have to eat characters and notify some other routine for a character press through Windows messages.
Example:
...
// Pseudocode
if (kbd->vkCode is character) {
if (WM_KEYDOWN == wParam) {
PostMessage(mainwnd, WM_MY_KEYDOWN, kbd->vkCode, 0);
return 1; // eat the char, ie 'a'
}
}
return CallNextHookEx(kbdhook, code, wParam, lParam);
And, in some other module, you handle WM_MY_KEYDOWN:
ie, #define WM_MY_KEYDOWN (WM_USER + 1)
and call the appropriate routine that will generate new key events.