I am writing a small test program, and for that i require the handle of an edit control. I have copied the value of the handle from Spy ++ (lets say 000A0B40).
So i did the following
#define editControlHandle 0x000A0B40
int *intHandle;
intHandle=(int*)editControlHandle;
HWND handle=(HWND)intHandle;
int textlength=GetWindowTextLength(handle);
I also did a getlasterror and it gave me error_success.
GetWindowTextLength cannot retrieve the length of the text of an edit control in another application.
Documentation
Related
I'm having a problem here and the problem is that the hService is 0
I'm having or creating the Windows Form application and I've put:
HSERVICE hService=0;
BOOL fSuccess=EXIT_SUCCESS;
if(Wfs_Startup())
{
// This returns a successful startup even if I write something here
// to be displayed by a textbox it does. That means the Startup is ok.
if(Wfs_Open(&hService))
{
// What ever I put here doesn't show on a textbox and the application jumps to
// the exception of this block which means there's a problem here, at first I
// thought it was because of no corresponding logical name on a registry but what
// I found out was that if I check below the Startup block and check the hService
// it's 0 so it doesn't receive the correct data from the startup.
}
}
so I took that from "I will say" a function that is written like this:
int WINAPI WinMain(HINSTANCE hInstance, HINSTANCE hPrevInstance, LPSTR lpCmdDLine,
int nShowCmd)
{
//THE CODE BLOCK IS THE SAME AS THE ABOVE THAT GOES HERE.
}
So I took the inside code block to FormLoad but this is giving me the above mentioned problem, can I have both the FormLoad and the WinMain? Because I tried to have the WinMain but there was an error I think it said there can't be two Main or something like that. Also how can I call the WinMain within FormLoad as when I tried it required the arguments to be included and the main problem is that I can't add the arguments in a FormLoad.
any suggestion to how can I resolve this problem?
Sorry but don't know the easy way to explain this. But keep in mind the problem that the hService returns 0.
Ok just to simplify this question:
How to call this type of Function that's starts with HRESULT at the beginning please check above. What I want is to fire that Function, I think that will simplify this even though there's another question about calling it on FormLoad but first I want to know how to call/fire that kind of Function?
The problem is that the IDE says I can not have the int WinMain on Windows Form because its already has something like that but when I'm working with command its works. I can have WinMain and Main but can't have WinMain and FormLoad not inside but within the project or page. To understand please create a Windows Form App and try typing the int WinMain code you will see what's my problem here.
I have found the great tutorial that gives a good reason why I'm getting this problem:
https://msdn.microsoft.com/en-us/library/bb384843.aspx
I'm new to win32 programming and haven't worked around with cpp for a long time. What I intend to do is to get a window's HWND via spy++, and get the text of this window. The problem is that I don't know how to create a HWND object, could anyone give me some idea? Thanks a lot!
If you have the numeric value of the HWND, you can cast it to the right type. Start with an integer of the right size, e.g.:
uintptr_t numeric_hwnd = 0x987654;
HWND hwnd = reinterpret_cast<HWND>(numeric_hwnd);
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.
So i am playing/implementingtomyown with windows via c book examples and there is something about dll injection part that boggles me and i can't solve it.
I created a dialog that belongs to another thread/process and i am trying to send it TCHAR variable so it can then use that var in some function(both the function and tchar are in the same dll file)
So when the dialog is created and sitting well in another thread i send it a message.
First i declare tchar
TCHAR finalpath[MAX_PATH];
Then later i just fill it with info( i do this in the dll thread, not in the dialog's thread, let me also mention that i must do this in the dll thread because thats only way to fill the required tchar(i am required to get dll working directory and fill it in tchar))
So, when i get this info in my tchar i am trying to send a message to the dialog and use tchar as LPARAM(wparam is hwnd btw)
SendMessage(hWndDIPS, WM_APP, (WPARAM) lista, (LPARAM)finalpath);
Afterwards i do basic schoolwork in another threads dialog procedure loop...
INT_PTR WINAPI Dlg_Proc(HWND hWnd, UINT uMsg, WPARAM wParam, LPARAM lParam) {
switch (uMsg) {
chHANDLE_DLGMSG(hWnd, WM_CLOSE, Dlg_OnClose);
case WM_APP:
SaveListViewItemPositions((HWND) wParam, (TCHAR)lParam);
break;
}
return(FALSE);
}
Function that is supposed to receive the parameter(this function resides in shared dll and is called by the procedure as you see above is defined as follows..
void SaveListViewItemPositions(HWND hWndLV, TCHAR sejv[]) {
...}
The compiler error i get from this is
Error 7 error C2664: 'SaveListViewItemPositions' : cannot convert parameter 2 from 'TCHAR' to 'TCHAR []'
So i have no idea why is this happening. If tchar is array then i need to use it in parameters with [] added as thats how arrays are used in parameters(not to mention that if i dont do it it gives me more errors and i cant use the parameter in function anyways)
So why is it not converting then?
If there is another solution to make this dialog to receive a tchar var then please explain.
Thanks
Even after you'll fix your type declarations and properly cast the LPARAM to a TCHAR*, your code will be incorrect. The 'parameter' you pass in to that window procedure is a pointer, and as any pointer, is only valid within a process address space. The receiver window will have to use ReadProcessMemory and copy the string from your process into its own process. Of course, this implies that the receiver process knows your process id, and has proper privileges to be able to read from your memory. And you also need to pass in the length of the string, since ReadProcessMemory cannot guess where the NULL terminator is (although I reckon that with a MAX_PATH max length, this is not a serious issue).
So you are correct, this is a headache, and more so down the road. The privilege issue may be a show stopper.
There are several IPC mechanisms you could use. An easy one is an anonymous named pipe, see Anonymous Pipe Operations. Shared memory is another, see Using Shared Memory in a Dynamic-Link Library. COM would also work (have the process you 'control' create an instance of a class that is hosted in your process server, and let the COM marshaling do the rest, see Marshaling Details). Or you could hand-marshal a COM interface between the process boundary (see CoMarshalInterface).
I think that your problem is that you're typecasting the LPARAM to a TCHAR instead of an array of TCHARs (TCHAR*). Try changing that and see if it fixes things.
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.