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I just stumbled on this little annoying behavior, while adding full screen support on a sample program.
Creating a full screen window works, but as soon as I move any window (from another application) on the output that contains my fullscreen window, it automatically switches back to windowed.
Is there any way to prevent this behavior (so full screen window do not go back to windowed)?
As a reference, this is a small standalone example (so problem can be replicated easily).
Also if that is useful, I'm running on Windows 8.1.
I already tried to change WindowAssociationFlags and SwapChainFlags, both with no success, same as using FlipSequential instead of Discard
SharpDX.DXGI.Factory2 factory = new SharpDX.DXGI.Factory2();
SharpDX.DXGI.Adapter adapter = factory.GetAdapter(0);
var renderForm1 = new RenderForm("Form 1");
factory.MakeWindowAssociation(renderForm1.Handle, SharpDX.DXGI.WindowAssociationFlags.IgnoreAll);
Device device = new Device(adapter, DeviceCreationFlags.BgraSupport);
SharpDX.DXGI.SwapChainDescription sd = new SharpDX.DXGI.SwapChainDescription()
{
BufferCount = 2,
ModeDescription = new SharpDX.DXGI.ModeDescription(0, 0, new SharpDX.DXGI.Rational(50, 1), SharpDX.DXGI.Format.R8G8B8A8_UNorm),
IsWindowed = true,
OutputHandle = renderForm1.Handle,
SampleDescription = new SharpDX.DXGI.SampleDescription(1,0),
SwapEffect = SharpDX.DXGI.SwapEffect.Discard,
Usage = SharpDX.DXGI.Usage.RenderTargetOutput,
Flags = SharpDX.DXGI.SwapChainFlags.None
};
var swapChain1 = new SharpDX.DXGI.SwapChain(factory, device, sd);
renderForm1.Left = 1922; //Just hardcoded here to move window to second screen
renderForm1.Width = 1920;
renderForm1.Height = 1080;
renderForm1.FormBorderStyle = FormBorderStyle.None;
swapChain1.SetFullscreenState(true, null);
swapChain1.ResizeBuffers(2, 1920, 1080, SharpDX.DXGI.Format.R8G8B8A8_UNorm, SharpDX.DXGI.SwapChainFlags.AllowModeSwitch);
var resource = Texture2D.FromSwapChain<Texture2D>(swapChain1, 0);
var renderView = new RenderTargetView(device, resource);
RenderLoop.Run(renderForm1, () =>
{
device.ImmediateContext.ClearRenderTargetView(renderView, new SharpDX.Color4(1, 0, 0, 1));
swapChain1.Present(1, SharpDX.DXGI.PresentFlags.None);
});
Edit:
I also tried a c++ sample (just taken DirectX11 basic tutorial from Microsoft and added full screen switch), this leads to the same behavior, so this is not a SharpDX specific issue.
I looked at the message loop, and once this occurs, first fullscreen mode is changed back to windowed, and I receive a WM_DISPLAYCHANGE message).
This sounds like expected behavior. If you have a full screen 'exclusive' mode swapchain and the associated window loses focus, the system automatically switches the application out of full screen mode back to windowed mode by design.
With a single monitor, it mostly works as long as you have your applications' window sized to fill the display. Users can't use the mouse to change focus of your window, and it requires something like ALT+TAB to switch focus.
With multiple monitors, it's a real problem. If you click on another window on another display, your app loses focus and the full screen mode is again switched out. There are also limitations that prevent you from setting full screen 'exclusive' mode on more than one monitor.
Furthermore, on Windows Vista or later the notion of 'exclusive' mode is an illusion: the GPU is always shared anyhow. The 'focus' application gets priority whether it is a full screen or a windowed swap chain.
For a Windows desktop apps you have three choices for a full screen style experience:
Use the traditional full screen 'exclusive' mode with a window sized to fill the display, along with setting the display mode which may not be what the user has set for Windows generally. Here you have IsWindowed = false.
You set the window size to fill the full display (i.e. maximized). You can use windows styles to ensure that the window has no frame which results in a full screen style experience (WS_POPUP). Here you have IsWindowed = true, and you should be sure to set DXGI_MWA_NO_ALT_ENTER to avoid allowing DXGI to try to take you to use the 1 case.
You can do the same as 2 with IsWindowed = true and the borderless window sized to match the screen, but you change the display mode to something other than the system default. This is commonly referred to as 'fake full screen'. The display mode gets changed back whenever you exit the application.
1 has all has all the problems with multi-tasking and focus we just described. 2 and 3 allow system notifications and other pop-ups to show up over the game and not force a mode switch. 2 and 3 also work a lot better in multi-monitor setups where you can play your game on one display and use other apps on another display. For multi-tasking most people to prefer a classic window style with a frame border.
Windows Store UWP notions of full screen mode is basically like 2 above. You can't change the display mode with a UWP.
Debugging a full-screen setup is quite challenging. With multiple monitors, 2 and 3 can work with your debugger on the other screen. For true full-screen exclusive mode, really the only option is to use remote debugging from another PC.
Another issue with 1 and 3 is that you can set the display mode to something that won't sync with the display leaving the user with a system with no UI and no way to exit. Ideally with the right driver setup, the DXGI enumeration list does not contain unsupported modes, but it is something to be aware of. For this reason, your UI for selecting a display mode should have a timeout and you should make sure there's a reasonable way to abort the application with the keyboard if the display mode fails to sync at some point in the future. Using the existing display mode as we do in 2 above is always the safest option.
The main reason to use full screen exclusive mode (1) above is to try to get 'flip' rather than 'blit' of the backbuffer/frontbuffer. For most modern systems, this is a negligible performance difference. The other reason to go through the pain of using it is for SLI/Crossfire multi-GPU rendering going to a single display. There are a number of other optimizations required to really make that scenario work, and it's pretty niche. You should seek out the vendor optimization guides for the details.
Most modern games default to using fake full screen rather than full screen 'exclusive' mode. They offer the ability to use a true windowed mode as many users want to be able to multi-task while playing (like looking up hints online, use IM or external voice chat, etc.). AAA Windows desktop games that want to support tuned high-performance gaming for SLI/Crossfire will offer a full screen 'exclusive' mode, but this requires some work to get working fully and entails more work than just some DXGI code.
See DXGI Overview and DirectX Graphics Infrastructure (DXGI): Best Practices
After several attempts and trials, here are the different workarounds I used, none are ideal but all are somehow better than getting a mode change.
1/Force cursor in the middle of the full screen window, with a keyboard shortcut to get control again.
This is not ideal since we can't really do anything while our part is running, but at least prevents accidental "disaster click". It does not prevent keyboard interaction either.
2/Use a DX9 renderer with a shared texture.
DX9 Swapchain can have it's parent window set to desktop, so it does not lose focus when moving to something else.
Having a focused window on top show little borders visible while moving it, but that is a bit more acceptable than losing everything.
Not future proof but guess will stay actual for a while.
3/Stay on Windows 7 and Disable DWM Service:
Doesn't work in Windows 8 anymore, but in my use case since most media companies I work for are still on Windows 7, it stays a valid solution for at least 5 to 10 years.
4/Force the DX11 Window on foreground
Basically continuously call SetForegroundWindow to avoid another window to take focus.
5/Prevent mode switch at presentation level.
Since on my application I got access to when presentation occurs, I use the following routine (before to call Present)
-Get Foreground window handle (using GetForegroundWindow), If Foreground handle is our fullscreen window, just call Present as usual.
If Foreground handle is not our fullscreen window, perform the following. Please note that visibility check is not needed, since even an invisible overlapping window will also cause a full screen loss! (seriously, this is just so bad...)
-Verify if our foreground window overlaps with the monitor:
Call GetWindowRect to get the bounds, and perform intersection with the monitor location.
Alternatively, call Present on the swapchain with the DXGI_PRESENT_TEST flag. If a window is overlapping, the Present call will return DXGI_STATUS_OCCLUDED
If a window overlaps, either Hide it or move it in another monitor (anywhere so it does not overlap):
ShowWindow and SetWindowPos are aperfect fit for this task.
Repeat that Test present call in a loop until it doesn't return the occluded status (this is important, since windows might not have processed the messages immediately); Once occluded flag is gone, call Present as usual.
There is a way to prevent DXGI from automatically leaving fullscreen mode when your process loses focus, though I must warn, it is a bit hackish.
Basically DXGI calls GetForegroundWindow() and checks if the returned window is yours.
If not, it switches off the fullscreen mode.
So if you hook/redirect this function to your own replacement, that always returns your window (regardless of whether it has the focus or not) - that will get the job done.
Here is a simple code that does that. It is for 64-bit mode and assumes that you NEVER need to call the real function, so it simply overwrites its start with a jump instruction to your replacement:
HWND WINAPI get_our_window()
{
return our_window;
}
void disable_automatic_leaving_fullscreen_on_lost_focus()
{
// get the address of GetForegroundWindow
char *p = (char *)GetProcAddress(GetModuleHandleA("user32.dll"), "GetForegroundWindow");
// make the function code writable
DWORD old;
VirtualProtect(p, 12, PAGE_EXECUTE_WRITECOPY, &old);
// overwrite the function start:
// mov rax, <address_of_GetOurWindow>
p[0] = 0x48, p[1] = 0xB8, *(void **)(p + 2) = (void *)get_our_window;
// jmp rax
p[10] = 0xFF, p[11] = 0xE0;
}
This code is only for demonstration.
If you need to retain the ability to call the true function, then you have to hook it in a different, more complicated way, but this is a separate subject
I was investigating an issue related to losing focus and changing activation of windows. What I found was that if I create an invisible property sheet, the active/foreground window changes and so does the focus window. Here is some sample MFC code:
// ignore CAutoDeleter, just a template that calls "delete this " in PostNcDestroy()
CPropertySheet* pSheet = new CAutoDeleter<CPropertySheet>(_T("Test Sheet"));
CTestPage* pPage = new CAutoDeleter<CTestPage>();
pSheet->AddPage(pPage);
DWORD style = WS_SYSMENU | WS_POPUP | WS_CAPTION | DS_MODALFRAME | DS_CONTEXTHELP;
// style |= WS_DISABLED; //does nothing to help
DWORD exStyle = 0;
//exStyle = WS_EX_NOPARENTNOTIFY|WS_EX_NOACTIVATE; // does nothing to help
pSheet->Create(AfxGetMainWnd(), style, exStyle); // adding
After the call to pSheet->Create(), the active/foreground/focus window has changed and the application window is on top. If I use Spy++ and look at the window that is created, it turns out that a property sheet is a DIALOG window class. I am assuming it has a different WNDPROC, of course. What is interesting, is if I create an invisible modeless dialog using, it does not exhibit the problem. If I create the invisible modeless dialog, the active/foreground/focus window remains the same.
I tried setting various flags as in the code snippet, but alas they did not have any discernible effect--I still had the flashing and activation non-sense.
I could get some improvement by setting and clearing a hook (WH_CBT) before and after pSheet->Create()--and then eating the activation messages. When I do that, I don't have the horrible flashing and my application window does not come to the top. However, the focus (and caret for windows that have carets) does go away from whichever window had it before the Create().
Does anyone know a way to keep the focus and activation unchanged when creating an invisible property sheet? (At some point, the property sheet may or may not be set visible. And, if the property sheet is invisible when being destroyed, it also causes the blinking and activation changes.)
I tried using the values returned in GetUIThreadInfo() to try and restore things after the call to Create(), but it causes some flashing as well.
I just want to know how to create an invisible Property Sheet which won't cause the active, foreground, and focus window to change.
Unfortunately the underlying API function PropertySheet calls SetForegroundWindow on the main property sheet dialog after creation. There's no easy way around this - your kludge with the WH_CBT hook is probably your best option.
Edit: As suggested by #stephen in the comments on this duplicate question, you may be able to prevent the activation/focus change using LockSetForegroundWindow.
I have been struggling with this same issue for weeks, with a similar project, where my main application launches a secondary EXE process to act as a server in an audio application (which needs to be a separate process to shield the application from plugin faults, and so it can be high priority for real-time audio processing).
My secondary EXE is a modeless CPropertySheet, for status and diagnostic display, but is intended to be launched hidden and in the background. However it was always stealing the activation from the main application on launch, regardless of what workarounds I tried (such as overriding OnWindowPosChanging).
I thought I was going to go mad, so I was very happy to find this question. The WH_CBT trick is useful, but I found while it prevented activation of the secondary EXE, it did not prevent deactivation of the main application.
But then I discovered an excellent solution, in the LockSetForegroundWindow API (available since Win2K) which I had never heard of before. Looks like it is intended for exactly this purpose, to disable the change of foreground activation and prevent peer processes from stealing it.
https://msdn.microsoft.com/en-us/library/windows/desktop/ms633532(v=vs.85).aspx
It works very well to nullify the internal call to SetForegroundWindow that happens deep within the property sheet common control, and works equally well whether used in the main application before CreateProcess or in the secondary EXE. I chose the latter case, to wrap the property sheet creation:
LockSetForegroundWindow(LSFW_LOCK);
pSheet->Create(NULL, dwStyle, dwExStyle);
LockSetForegroundWindow(LSFW_UNLOCK);
This minimises the scope of the intervention and keeps the fix localised to the process that is the source of the problem. I hope this will save others from wasting as much time on this tedious issue as I did.
I was investigating an issue related to losing focus and changing activation of windows. What I found was that if I create an invisible property sheet, the active/foreground window changes and so does the focus window. Here is some sample MFC code:
// ignore CAutoDeleter, just a template that calls "delete this " in PostNcDestroy()
CPropertySheet* pSheet = new CAutoDeleter<CPropertySheet>(_T("Test Sheet"));
CTestPage* pPage = new CAutoDeleter<CTestPage>();
pSheet->AddPage(pPage);
DWORD style = WS_SYSMENU | WS_POPUP | WS_CAPTION | DS_MODALFRAME | DS_CONTEXTHELP;
// style |= WS_DISABLED; //does nothing to help
DWORD exStyle = 0;
//exStyle = WS_EX_NOPARENTNOTIFY|WS_EX_NOACTIVATE; // does nothing to help
pSheet->Create(AfxGetMainWnd(), style, exStyle); // adding
After the call to pSheet->Create(), the active/foreground/focus window has changed and the application window is on top. If I use Spy++ and look at the window that is created, it turns out that a property sheet is a DIALOG window class. I am assuming it has a different WNDPROC, of course. What is interesting, is if I create an invisible modeless dialog using, it does not exhibit the problem. If I create the invisible modeless dialog, the active/foreground/focus window remains the same.
I tried setting various flags as in the code snippet, but alas they did not have any discernible effect--I still had the flashing and activation non-sense.
I could get some improvement by setting and clearing a hook (WH_CBT) before and after pSheet->Create()--and then eating the activation messages. When I do that, I don't have the horrible flashing and my application window does not come to the top. However, the focus (and caret for windows that have carets) does go away from whichever window had it before the Create().
Does anyone know a way to keep the focus and activation unchanged when creating an invisible property sheet? (At some point, the property sheet may or may not be set visible. And, if the property sheet is invisible when being destroyed, it also causes the blinking and activation changes.)
I tried using the values returned in GetUIThreadInfo() to try and restore things after the call to Create(), but it causes some flashing as well.
I just want to know how to create an invisible Property Sheet which won't cause the active, foreground, and focus window to change.
Unfortunately the underlying API function PropertySheet calls SetForegroundWindow on the main property sheet dialog after creation. There's no easy way around this - your kludge with the WH_CBT hook is probably your best option.
Edit: As suggested by #stephen in the comments on this duplicate question, you may be able to prevent the activation/focus change using LockSetForegroundWindow.
I have been struggling with this same issue for weeks, with a similar project, where my main application launches a secondary EXE process to act as a server in an audio application (which needs to be a separate process to shield the application from plugin faults, and so it can be high priority for real-time audio processing).
My secondary EXE is a modeless CPropertySheet, for status and diagnostic display, but is intended to be launched hidden and in the background. However it was always stealing the activation from the main application on launch, regardless of what workarounds I tried (such as overriding OnWindowPosChanging).
I thought I was going to go mad, so I was very happy to find this question. The WH_CBT trick is useful, but I found while it prevented activation of the secondary EXE, it did not prevent deactivation of the main application.
But then I discovered an excellent solution, in the LockSetForegroundWindow API (available since Win2K) which I had never heard of before. Looks like it is intended for exactly this purpose, to disable the change of foreground activation and prevent peer processes from stealing it.
https://msdn.microsoft.com/en-us/library/windows/desktop/ms633532(v=vs.85).aspx
It works very well to nullify the internal call to SetForegroundWindow that happens deep within the property sheet common control, and works equally well whether used in the main application before CreateProcess or in the secondary EXE. I chose the latter case, to wrap the property sheet creation:
LockSetForegroundWindow(LSFW_LOCK);
pSheet->Create(NULL, dwStyle, dwExStyle);
LockSetForegroundWindow(LSFW_UNLOCK);
This minimises the scope of the intervention and keeps the fix localised to the process that is the source of the problem. I hope this will save others from wasting as much time on this tedious issue as I did.
I am trying to capture windows hidden behind my application. I am using windows 7 and VC++. I have tried printwindow() function which draws the both non-client and client area of hidden window, but captured window in the device context doesn't show desktop composition effects(aero effects). Instead it shows the captured window with windows 7 basic theme.
I have also tried with GetWindowDC() to retrive the DC of hidden window, and then Bitblt() it to memory DC but the captured window doesn't show non-client area (caption, close button, minimize button etc) correctly.
Anybody faced this issue?
Please help.
Click the link below. It leads to a MSDN site that lists all the existing Windows Functions ever of all history since Windows 95 up to Windows 8 (from period where Microsoft started Windows until present). It shows old windows functions of first Windows and new windows functions added for the new windows.
http://msdn.microsoft.com/en-us/library/windows/desktop/ff468919(v=vs.85).aspx
Anyway follow this site.
You will see the name of each function as a link.
Click any of them that you are interested.
Each link there leads to another MSDN site that explains all the basics knowledge that you must know about the function before using it, that you want to learn more. What that function does, its purpose, all its parameters and how to use each one, all their flags, all parameters types, return value and at last remarks section that shed more light and sometimes gives tips about the selected function.
Of course, you don't have to read all of them. Find in the list only the necessary functions to fit your needs. The functions that will solve your problem and answer your question that you posted.
By the way, I read your post, and I think that I found in the list the necessary functions that will do what you want to do, I will list them below, and say in one sentence what each does for what you need:
AnimateWindow - Enables you to produce special effects when showing or hiding windows. There are four types of animation: roll, slide, collapse or expand, and alpha-blended fade.
FlashWindow - Flashes the specified window one time. It does not change the active state of the window.
FlashWindowEx - Flashes the specified window specified number of times. It does not change the active state of the window.
Use these functions to achieve the aero effects that you want.
SetWindowPos - Changes the size, position, and Z order of a child, pop-up, or top-level window. These windows are ordered according to their appearance on the screen. The topmost window receives the highest rank and is the first window in the Z order.
Use this function to show the hidden windows on the top side (above all other windows) and on the screen front of you. The operating system will automatically draw the both non-client and client area of these windows without using any gdi, draw and paint functions yourself.
If you want these windows to return back to their previous state (where they were hidden), then save their state with GetWindowPlacement function and later call SetWindowPlacement to bring them back to their hidden state. You can try GetWindowRect and SetWindowPos instead to achieve the same goal.
I also think that you will be interested in GetWindowTheme and SetWindowTheme functions and all the draw theme functions (BackgroundEx, Edge, Icon, Text, TextEx).
There are more theme functions. Find in msdn and in other sites on the web.
In Windows, is it possible to set window A such that it is always on top of window B, yet allow other windows to work as normal and appear over the top of both, when active.
In other words, I want a parent-child relationship between two windows. Can this be done without making window A a child of window B, MDI-style? Window B isn't mine (Internet Explorer), and screws my dialog A's graphics up when I try to achieve this with SetParent.
I thought I'd cracked it with this idea from an MSDN forum post, but alas windows A is still always on top of everything, not just window B.
// Place window A on top
SetWindowPos(hWndWindow, HWND_TOPMOST, 0, 0, 0, 0, SWP_NOMOVE|SWP_NOSIZE);
// Place window B underneath it
SetWindowPos(hWndParent, HWND_NOTOPMOST, 0, 0, 0, 0, SWP_NOSIZE|SWP_NOMOVE);
Is it possible?
Wouldn't creating an ownership relationship do the trick?
SetWindowLong(hwndChild, GWL_HWNDPARENT, hwndOwner)
The windows can be in different processes and you can call this from any process. This will ensure that the child window is always above the owner window. This is different than SetParent which actually creates a Parent / Child relationship. Read through this article (its from 1993 but still mostly correct) to see the distinction between ownership and parenting.
When your window's Z-order (or size or position) is changing, it should receive a WM_WINDOWPOSCHANGING message. If you process that message, you have an opportunity to modify the final Z-order (or size or position) to which the window is moved.
To illustrate, in hWndA's window procedure:
case WM_WINDOWPOSCHANGING:
DefWindowProc(hWnd, msg, wParam, lParam);
WINDOWPOS *p = (WINDOWPOS*)lParam;
p->hwndInsertAfter = hWndB;
p->flags &= ~SWP_NOZORDER;
return 0;
should insert hWndA after hWndB in the Z-order any time hWndA's position changes.
Until Vista, one way to do it would have been to use SetWindowsHookEx, and hook the WH_CBT or WH_CALLWNDPROC hook, and then take appropriate action when you detect the Z order changing. However this doesn't work with Vista (as far as I can tell from googling).
The only other solution I can think of is to set up a timer to fire every few seconds, and then when you receive a WM_TIMER, you interrogate the system using GetNextWindow to find out which window is behind yours. If it's not IE, then call SetWindowPos to position your window above IE (I assume you have a HWND for the IE window you care about - remember there can be multiple IE windows).
This will cause problems if people try to bring your window to the front - it will flip back to being just above IE. In this case, in your code you could handle WM_ACTIVATE and try to change the Z-order of IE's window so it's below your window (call SetWindowPos to move IE's window so it's above the window that is currently below your window). This solution may be fraught with problems as Windows may try to prevent you messing with the windows of another process, for security reasons. On the other hand, the MSDN docs for SetWindowPos don't explicitly mention that you can't manipulate the windows of another process. There may be obscure limitations though.
Even with this timer hack, you're going to effectively have a busy-waiting loop in your app (with the frequent WM_TIMER messages) and this is generally a bad thing to do, especially for battery life of laptops etc. (because you prevent the CPU from entering a sleep state, and so on).
I'd say there's no good way of doing this, and anything you're likely to get working will be brittle and cause problems. I strongly recommend not trying to do it. Is it possible to make your program into some kind of plug-in or toolbar for IE instead?
NB Be particularly aware that SetWindowsHookEx imposes a performance penalty at a system-wide level if you go down this route.
Maurice's answer is the best out of what's here but is missing an important step. When you call show on your window that you want as the overlay, you need to call the show method that has the parameter. You'll need to define a class that implements the IWin32Window interface and just make a new instance of that. The only thing that interface cares about is the Handle so just set that to the handle of the IE window and it should work pretty well
If the parent-child relationship is made by yourself with the SetWindowPos() function, your desire can be implemented.
Can you access the Z-order of the windows?
I cannot recall the default z-order of windows, but I think it is 1. You might be able to set IE to a -1 and your app to 0.
Try this:
// Place window A on top of window B
SetWindowPos(hWndA, hWndB, 0, 0, 0, 0, SWP_NOMOVE|SWP_NOSIZE);
The second window handle parameter specifies the next window down in the Z order.
Note this doesn't actually change the window parent-child relationships - but you can simulate it.