Home > General x86, General x86-64, Programming > Code Snippets: FindWindowLike

Code Snippets: FindWindowLike

Like many developers who write code in their free time, I have an overwhelming backlog of side projects. A lot of these projects don’t get finished for the usual variety of reasons: lack of time, loss of interest, another side projects comes up, and so on. As I searched through the folders of these projects, I realized that while I might not be able to complete them now or in the future, that there are certain portions of them that I can carve out and post about. These snippets will typically be short code blocks that I had written to solve a rather particular problem at the time.

The code snippet covered here will be a function I wrote called FindWindowLike. Interestingly enough, while Googling this, there appears to be an MSDN article from 1997 which lists a VB6 function that does the same thing. The one posted here is implemented much differently than that horrible mess though. The purpose of this function is to get a handle to a window while knowing only part of its title. This was useful when I was trying to get a window handle which changed on every instance of the program — for example the process id was part of the title. The code is very straightforward and uses EnumWindows to enumerate all windows on the desktop and perform a substring match.

typedef struct
{
    const TCHAR * const pPartialTitle;
    const bool bCaseSentitive;
    HWND hFoundHandle;
} WindowInformation;
 
BOOL CALLBACK EnumWindowsProc(HWND hWnd, LPARAM lParam)
{
    //Read up to 255 characters of window title
    TCHAR strWindowTitle[255] = { 0 };
 
    auto success = GetWindowText(hWnd, strWindowTitle, sizeof(strWindowTitle));
    if (success > 0)
    {
        WindowInformation *pWindowInfo = (WindowInformation *)lParam;
        auto isFound = pWindowInfo->bCaseSentitive ?
            StrStr(strWindowTitle, pWindowInfo->pPartialTitle) :
            StrStrI(strWindowTitle, pWindowInfo->pPartialTitle);
        if (isFound)
        {
            pWindowInfo->hFoundHandle = hWnd;
            return FALSE;
        }
    }
 
    return TRUE;
}
 
const HWND FindWindowLike(const TCHAR * const pPartialTitle, const bool bCaseSensitive = true)
{
    WindowInformation windowInfo = { pPartialTitle, bCaseSensitive, nullptr };
    (void)EnumWindows(EnumWindowsProc, (LPARAM)&windowInfo);
 
    if (windowInfo.hFoundHandle == nullptr)
    {
        fprintf(stderr, "Could not find window.\n");
    }
 
    return windowInfo.hFoundHandle;
}

The sample code is hosted on GitHub here.

Categories: General x86, General x86-64, Programming Tags:
  1. No comments yet.
  1. No trackbacks yet.