Why cannot I just write:
GetWindowThreadProcessId("Name of Window", &PID);
instead of:
HWND Name = FindWindow(("Name of Window", NULL));
GetWindowThreadProcessId(Name, &PID);
What does the Handle function do ? Like, if there wasn't something special with HWND, if it just stores a string, why not just use "string", so what does it store ?
because if I do this:
cout << Name << endl;
it gives a string ???
I was thinking about if it stores a function:
GetWindowThreadProcessId(FindWindow(("Name"), NULL)), &PID);
From application view a window handle is an abstract value that uniquely identifies a window, see also What is a Windows Handle? or Handle in Wikipedia. The operating system might see it differently and see a window handle as a pointer to a struct with Information about the window. Or it might see the window handle as an index into an array, or as something totally different. But that is up to the operating system.
A window title is not unique, multiple windows can exist with the same title.
GetWindowThreadProcessId needs to know exactly on which window to work, so you cannot pass a window title to the function, but you need to pass a window handle.
Besides, cout << hwnd_value; will not work, it will just print a pointer value, not a string.
Related
I'm new to c++ and FindWindowA is working for some processes and not others, for example:
FindWindowA(NULL, "Discord"); will work
but FindWindowA(NULL, "Fortnite"); won't.
anyone know why?
Thanks.
FindWindow only finds top level windows. If you are searching for an exact match with the title of the window, then you must take into account hidden characters (space, tab, etc.).
Even if you find the window title, it will only work if that window isn't localized—i.e., if the program that creates that window is localized for a different language, then you must also localize your search string.
A more reliable approach is to search for the class name, since this will typically not be localized: FindWindow("myclass", NULL);
Of course this will still fail if there is a hidden top level window that creates a child window containing the window you are looking for. To get that window, you can call EnumWindows to get the handle of each top level window, and for each top level window found, you then call EnumChildWindows.
Fortnite's window has a space or two
sd.Flags = DXGI_SWAP_CHAIN_FLAG_ALLOW_MODE_SWITCH;
sd.OutputWindow = FindWindow((L"UnrealWindow"), (L"Fortnite "));
sd.SampleDesc.Count = 1;
sd.Windowed = TRUE;
I'm fairly new (about 10 weeks into an level 1 high school course) and I'm trying to see how I can format the command prompt window. I've learned how to set the size of the window, but not the position. I'm using code::blocks on a windows XP
First, Read This
Then, try these... (in a batch file)
Set mycmdHeight=40
Set mycmdWidth=80
Set mycmdxPos=0
Set mycmdyPos=120
Or, programmatically, look here or here
You can use windows function to move the console windows in your desire location.
First look the function to return the handle of current windows.
HWND WINAPI GetConsoleWindowNT(void)
{
// declare function pointer type
typedef HWND WINAPI (*GetConsoleWindowT)(void);
// declare one such function pointer
GetConsoleWindowT GetConsoleWindow;
// get a handle on kernel32.dll
HMODULE hK32Lib = GetModuleHandle(TEXT("KERNEL32.DLL"));
// assign procedure address to function pointer
GetConsoleWindow = (GetConsoleWindowT)GetProcAddress(hK32Lib,TEXT("GetConsoleWindow"));
// check if the function pointer is valid
// since the function is undocumented
if ( GetConsoleWindow == NULL ) {
return NULL;
}
// call the undocumented function
return GetConsoleWindow();
}
Use above function to get the handle of current window.
HWND hwnd = GetConsoleWindowNT();
Now, you can move your windows at your desire location using MoveWindow function like below:
MoveWindow(hWnd,1230,750,200,100,TRUE);
You can get the complete sample program here.
I have this code:
HWND WindowHandle;
WindowHandle = FindWindowA( WindowClass, WindowName );
if( WindowHandle != NULL)
{
// here I want to populate a listbox with the window's information like
// its process name and PID, executable file name, and its window title.
}
I already know how to get the Window Title, with SendMessage(); and WM_GETTEXT, but I want to know how to get it's process name and PID, and also the executable file location and name.
Could anyone help me?
Please note that I am working with C++ MFC.
Windows offers a function called GetWindowThreadProcessId.
It sounds like what you want.
Disclaimer: I haven't used it.
You can find the PID in PROCESS_INFORMATION. Just declare say: PROCESS_INFORMATION pi and access PID like this: pi.hProcesss pi.dwProcessId.
I want to send keystrokes to multiple processes. For example, if I press “1”, then I want to send the “1” to 3 "Notepad windows". Frist I want to try to send a keystroke to notepad, but it fails on the HWND:
//HANDLE hWin;
HWND windowHandle = FindWindowA(NULL, "Notepad"); //Can’t find a proccess
//Send a key
if( windowHandle ) //This one fails
{
while(true)
{
if( GetAsyncKeyState(VK_F12) != 0 )
{
SendMessageA(windowHandle, WM_KEYDOWN, VK_NUMPAD1, 0);
Sleep(1000);
SendMessageA(windowHandle, WM_KEYUP, VK_NUMPAD1, 0);
}
Sleep(100);
}
}
But the "FindWindow" method is not good enough for my program. There is also no way to get 3 different processes with the same name. So how can I make 3 handles to 3 different processes with the same name? And how can I send key’s to the processes?
You can use EnumWindows for enumerating all the top level windows on the system. You then need to filter through these windows to get the ones you are interested in. Class name is probably a better choice for filtering rather than the window name though. Here is some example code (not tested) of what I have in mind:
BOOL CALLBACK BroadcastToNotepad(HWND hwnd, LPARAM lParam)
{
wchar_t lpClassName[16];
/*
* More reliable to filter by class name. We could additionally filter
* by caption name too if necessary.
*/
if(GetClassName(hwnd, lpClassName, _countof(lpClassName))) {
if(wcscmp(lpClassName, L"Notepad") == 0) {
SendMessage(hwnd, WM_KEYDOWN, (WPARAM)lParam, 0);
Sleep(1000);
SendMessage(hwnd, WM_KEYUP, (WPARAM)lParam, 0);
}
}
return TRUE;
}
// Some handler which gets invoked when your hotkey is hit.
void handlerKey1(...)
{
EnumWindows(BroadcastToNotepad, (lParam)VK_NUMPAD1)
}
Note the usage of BroadcastToNotepad and how you can have different handlers pass in a different lParam.
One final thing to note is that PostMessage/SendMessage is not a reliable way to simulate keyboard input. This is noted by Raymond Chen here. SendInput is the preferred way for injecting input. However, to use that you will need to ensure the window you want to send to has the keyboard focus.
I recall vaguely having played with something similar to what you are doing in the past. If I remember correctly, you need to send to Notepad's child window (class name = Edit). So the code above needs to be modified as so:
if(wcscmp(lpClassName, L"Notepad") == 0) {
HWND hwndChild = FindWindowEx(hwnd, NULL, L"Edit", NULL);
SendMessage(hwndChild, WM_KEYDOWN, (WPARAM)lParam, 0);
Sleep(1000);
SendMessage(hwndChild, WM_KEYUP, (WPARAM)lParam, 0);
}
Firstly install Spy++ from Visual Studio which lets you see all the HWND windows in hierarchy ( and which process owns them).
Then you'll see why your FindWindow is failing. You'll also know the exact hierarchy calls to make on FindWindow and GetWindow().
Be aware that since Vista some HWNDs are protected and you cant send to them - but notepad is probably fine.
For sending the key, you can probably just use PostMessage to fire and forget.
First of all, why is while(true) there? Wouldn't you rather want to activate your software on F12 key press than having an infinite loop? That handle is not valid forever, you know.
Second, you'd probably want to use EnumWindows to go through all the windows and find the one you're interested in. Then you'd implement a callback function that'll need to decide on some basis if it wants to act on some window or not (be it name or something else).
SendMessage/SendMessageA/SendMessageW should work just fine when you've found a proper handle for the window you want to target for (save for some special windows that are protected from this).
Is there a way for a Windows application to access another applications data, more specifically a text input field in the GUI, and grab the text there for processing in our own application?
If it is possible, is there a way to "shield" your application to prevent it?
EDIT: The three first answers seem to be about getting the another applications window title, not a specific text input field in that window.
I'm no Windows API expert, so could you be more exact how do I find a certain text field in that window, what are the prerequisites for it (seems like knowing a window handle something is required, does it require knowing the text field handle as well? How do I get that? etc...)
Code snippets in C++ really would be really appreciated. MSDN help is hard to browse since Win32-API has such horrible naming conventions.
Completed! See my answer below for a how-to in C++.
For reading text content from another application's text box you will need to get that text box control's window handle somehow. Depending on how your application UI is designed (if it has a UI that is) there are a couple of different ways that you can use to get this handle. You might use "FindWindow"/"FindWindowEx" to locate your control or use "WindowFromPoint" if that makes sense. Either way, once you have the handle to the text control you can send a "WM_GETTEXT" message to it to retrieve its contents (assuming it is a standard text box control). Here's a concocted sample (sans error checks):
HWND hwnd = (HWND)0x00310E3A;
char szBuf[2048];
LONG lResult;
lResult = SendMessage( hwnd, WM_GETTEXT, sizeof( szBuf ) / sizeof( szBuf[0] ), (LPARAM)szBuf );
printf( "Copied %d characters. Contents: %s\n", lResult, szBuf );
I used "Spy++" to get the handle to a text box window that happened to be lying around.
As for protecting your own text boxes from being inspected like this, you could always sub-class your text box (see "SetWindowLong" with "GWL_WNDPROC" for the "nIndex" parameter) and do some special processing of the "WM_GETTEXT" message to ensure that only requests from the same process are serviced.
OK, I have somewhat figured this out.
The starting point is now knowing the window handle exactly, we only know partial window title, so first thing to do is find that main window:
...
EnumWindows((WNDENUMPROC)on_enumwindow_cb, 0);
...
which enumerates through all the windows on desktop. It makes a callback with each of these window handles:
BOOL CALLBACK on_enumwindow_cb(HWND hwndWindow, LPARAM lParam) {
TCHAR wsTitle[2048];
LRESULT result;
result = SendMessage(hwndWindow, WM_GETTEXT, (WPARAM) 2048, (LPARAM) wsTitle);
...
and by using the wsTitle and little regex magic, we can find the window we want.
By using the before mentioned Spy++ I could figure out the text edit field class name and use it to find wanted field in the hwndWindow:
hwndEdit = FindWindowEx(hwndWindow, NULL, L"RichEdit20W", NULL);
and then we can read the text from that field:
result = SendMessage(hwndEdit, WM_GETTEXT, (WPARAM) 4096, (LPARAM) wsText);
I hope this helps anyone fighting with the same problem!
Look at AutoHotkey. If you need an API for your application, look at their sources.
To prevent it, use a custom widget instead of WinForms, MFC or Win32 API. That is not foolproof, but helps.
Yes it is possible in many ways (one way is to use WINAPI GetWindow and GetWindowText).
First, get a handle to the textbox you want to retrieve text from (using FindWindow, EnumChildWindows and other APIs), then:
Old VB6-codeexample, declaration of API:
Private Declare Function GetWindowText Lib "user32" Alias "GetWindowTextA" (ByVal hwnd As Long, ByVal lpString As String, ByVal cch As Long) As Long
Private Declare Function GetWindowTextLength Lib "user32" Alias "GetWindowTextLengthA" (ByVal hwnd As Long) As Long
Code to extract text:
Dim MyStr As String
MyStr = String(GetWindowTextLength(TextBoxHandle) + 1, Chr$(0))
GetWindowText TextBoxHandle, MyStr, Len(MyStr)
MsgBox MyStr
About how to shield the application to prevent it, you could do many things.
One way would be to have a own control to handle text input that build up the text from lets say a couple of labels placed where the text would be, or that draws the text graphically.
You can also get text from a richedit control with EM_GETTEXTRANGE message, but it works only in the same process in which the control was created.