StackOverflow2013

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POWin32 SetForegroundWindow unreliable
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copied!<p>I have a rather complex series of applications which depend on the ability to switch applications in the foreground.</p> <p>My problem is, every 5 or 6 times of switching the applications in the foreground, it simply fails to bring the application forward. GetLastError does not report any issues. Often times I see the correct application flash in the foreground for a moment then the previous application is visible.</p> <p>I have a Manager application which I have source for, it spawns and controls about 4 applications which I do not have source for. one of the applications it spawns/controls is also a manager which spawns/controls about 5 applications.</p> <p>This is a sort of kiosk design so the user wont even have a keyboard or mouse, just a touch screen.</p> <p>I have tried every combination of the Win32 calls to control them I am just out of ideas.</p> <p>My first attempt was:</p> <pre><code>SetWindowPos(hApp, HWND_TOPMOST, NULL, NULL, NULL, NULL, SWP_NOMOVE | SWP_NOSIZE); SetWindowPos(hApp, HWND_NOTOPMOST, NULL, NULL, NULL, NULL, SWP_NOMOVE | SWP_NOSIZE); </code></pre> <p>My second attempt was:</p> <pre><code>SetForegroundWindow(hApp); SetActiveWindow(hApp); SetFocus(hApp); </code></pre> <p>my third attempt: DWORD dwThreadID = GetWindowThreadProcessId(hApp, NULL); AttachThreadInput( dwThreadID, GetCurrentThreadId(), true);</p> <pre><code>SetForegroundWindow(hApp); SetActiveWindow(hApp); SetFocus(hApp); AttachThreadInput( dwThreadID, GetCurrentThreadId(), false); </code></pre> <p>my forth attempt:</p> <pre><code>DWORD dwThreadID = GetWindowThreadProcessId(hApp, NULL); AttachThreadInput( dwThreadID, GetCurrentThreadId(), true); SetWindowPos(hApp, HWND_TOPMOST, NULL, NULL, NULL, NULL, SWP_NOMOVE | SWP_NOSIZE); SetWindowPos(hApp, HWND_NOTOPMOST, NULL, NULL, NULL, NULL, SWP_NOMOVE | SWP_NOSIZE); SetForegroundWindow(hApp); SetActiveWindow(hApp); SetFocus(hApp); AttachThreadInput( dwThreadID, GetCurrentThreadId(), false); </code></pre> <p>I feel like I am missing an important gotcha when it comes to window switching. I know that only the foreground process can switch windows around but as my main Manager program is spawning and starting all the other processes which I need to control, I feel like it should be capable of moving these windows around. Any suggestions or advice is appreciated.</p>

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