I am working on a simple active desktop replacement for a school that is migrating to Windows 7. The idea is to create a window with a few large buttons with pictures on so that young children who have trouble reading can use them.
I am using SetParent() to set my window's parent to 'Progman' so that it is always at the back and is not minimised when a user chooses to 'Show Desktop'. Everything works fine on Windows XP but on Windows 7 when users click 'Show Desktop' the window remains but the contents are replaced with the users Windows background. The buttons still work (you just can't see them) and if you resize or otherwise update the window they appear again. A picture of the problem:
Any ideas why this is happening? Does anyone know a way I could force a refresh of the window when 'Show Desktop' is pressed?
I suspect in your case your app is throwing an exception but not crashing. WPF apps have a tendency to do this if the exception is thrown during the ctor of some UI element. It can disrupt the rendering stack.
I tried to reproduce the problem but was unsuccessful. From my tests I was able to get the handle to 'Progman' and set the main window as the parent when using the Windows 7 basic theme (no Arrow glass).
When I used the Arrow theme, calling SetParent would cause the window to vanish. A little research turned up a possible fix. Instead of setting the parent as the 'Progman' window, you can try using the 'SysListView32' child (the child window used to hold the desktop icons).
The problem is obtaining 'SysListView32' isn't easy. It used to be a matter of traversing through 'Progman' to 'SHELLDLL_DefView' and then 'SysListView32', however, Windows 7 has changed that. 'SHELLDLL_DefView' is now a child of WorkerW.... some of the time.
Here is the best article I could find explaining this:
http://fernandomachadopirizen.wordpress.com/2010/08/09/give-me-a-handle-and-i-will-move-the-earth/
Related
When I open any dialog in my Winforms application then Windows 10 behaves oddly in these ways:
ALT-TAB no longer displays the list of windows
I cannot switch to hidden applications using taskbar icons - if I select a taskbar icon of a window that is not currently visible (even if it is not hidden by the winforms app) the icon just flashes and then stays highlighted, but is not brought to the foreground. I can use other applications that are visible. As soon as I close the dialog form the other I can use the windows of other applications correctly
If I switch to the application window that is behind the winforms application by clicking on it, I cannot go back to the winforms app either by ALT-TAB or by clicking on the taskbar icon. I can get back to it by minimizing the other application
I'm opening the dialogs with
dialogFormName.ShowDialog(this);
TopMost is set false on all forms and is not set in the code.
I've read about 50 related articles and the only problems seem to be either TopMost is set or ShowDialog is not called with the parent form. I'm not a regular Winforms developer so I'm probably doing something stupid. This is driving me crazy, so I'd really appreciate any help!
Edit: The same issues occur with MessageBox.Show(this, "test"). The issue does not occur with a newly created app just with a single button calling MessageBox.Show(this, "test"). The problem application uses EntityFramework but no other packages and the problem existed before I added EF.
After trying different scenarios I eventually found the issue. In my case I was calling ShowDialog() after a user clicks an item on a ContextMenu. The blocking of ALT-TAB was caused by the following code that attached the ContextMenu to the ListView that the menu was contextually for:
lstList.ContextMenu = myContextMenu;
As soon as I removed that association, the ShowDialog no longer blocked ALT-TAB.
Form.ShowDialog() blocks the parent form until it's closed.
Use Show() to display the form separately without blocking its parent.
I'm creating a Windows Forms application in C# that utilizes the SlimDX(a managed wrapper of the Direct3D API) libraries. Problems arise when I try to take the application fullscreen(a state in which the main window covers the entire desktop area including the taskbar).
The Direct3D device window(main window) displays correctly. The taskbar and other overlapping windows are hidden entirely by the device window. The cursor, however, seems to belong to the window directly beneath the device window. This is evident in the appearance and behavior of the cursor. When I click on the device window focus is changed to the window beneath. This is unexpected behavior for any window.
Also, I am able to click items on the taskbar which will cause a change in focus.
I am changing the window style of the device window to 'TopMost and 'Popup'. Also, I am following the utility class found in the DirectX SDK. When I run a sample from the DX SDK, which uses Win32, this problem doesn't occur. Is it possible that the problem is related to my use of Windows Forms?
There is a lot of code involved in my application so I was hoping for theoretical responses as to why this problem might occur. I found a thread here that describes a problem when taking device fullscreen, however, the solution is unacceptable. It was suggested to use a 'windowed fullscreen mode'. Instead of modifying the adapter display mode for fullscreen, the device window would simply be resized to cover the entire screen. This solution would prevent the use of adapter formats, resolutions, and refresh rates that are available in fullscreen mode.
Any suggestions would be much appreciated!
The problem was due to the nature of controls found in Windows Forms. From MSDN:
A control can be selected and receive input focus if all the following are true: the Selectable value of ControlStyles is set to true, it is contained in another control, and all its parent controls are both visible and enabled.
The device window in my application belongs to a parent window and the parent window becomes nonvisible once fullscreen is enabled. Its possible that a conflict arose due to the 'focus rules' above. To test the theory I examined the return value from DeviceWindow.Focus()(derives from Control.Focus())...which returned false.
My solution was to create a form used for the sole purpose of fullscreen mode changes. Now, when I want to go fullscreen I reset the device with the handle to the new device window. All problems solved...
I'm working on a rather big project with my team and after a while, we struck into a big problem.
Infact when we minimize the main window of the application, clicking on the taskbar to restore it results in a "bing" sound (the one that windows uses when you are trying to interact with a background window when a modal dialog is opened on it). I can't restore the window except if I press ENTER button (after obviusly clicking on it).
We are using XNA to render something inside a WindowsFormsHost component in our WPF application and the problem comes out when we change something that is not connected directly with wpf (something inside the rendering engine, so it works only with XNA).
I can't post any code because I don't own any rights of it and would be meaningless because the project is enough big.
So my question is: what are the things that can produce a problem like this one (unable to restore window sound) when you click on the taskbar?
At least I can understand where to search for this bug, because I don't even understand where I shall dirt my hands in.
Important notes: I'm using a splash screen and the problems come up when I do something on a second window (so not directly the main one) which is not modal
Thanks for any suggestion
We solved the problem by finding out that there is a bug with an external component that we used inside our application. Still I don't understand how this bug has been created, if someone has a better answer I'll mark it.
I have an application where the taskbar flashes if an event has occurred. This is working perfectly, and was relatively easy to implement using a Win32 API described below:
http://blogs.x2line.com/al/archive/2008/04/19/3392.aspx
However, when I stop the flashing, sometimes the application is stuck in the "highlighted" state in the taskbar. This only gets reset by clicking on the application in the taskbar, minimizing it, then re-maximizing it. Is there a way to clear this from being highlighted without any user interaction?
Maybe instead of flashing it you could put an overlay icon on it - one line of code from C# with the Code Pack. Then when you want to clear it you could take the overlay icon away - again one line of code. Windows 7 only, however.
Can you post the code that you are using to "Stop" the flashing?
Have you also considered using a different flag such as:
// flash until the window comes to the foreground
FLASHW_TIMERNOFG = 12;
You will still need to click on the applicaiton to get the flash to stop, but you should not have to minimize then re-maximize the app to get the flash to stop.
You can include the FlashTaskbar snippet and use the following code
FlashWindow(Form.Handle, FlashMode.FLASHW_STOP)
I have a fullscreen window, and I want to prevent pop up windows that appear at the right bottom corner of my screen. I set the Topmost property to true, but apparently it does not help. I also tried activating the form and giving it the focus once it got deactivated, but that did not help either. What is a way to ignore such windows while the user is engaged with the fullscreen app? I am .NET programming in C#.
You can't do it, this fails the "what if two programs tried to do this" test:
those popups are just normal windows like yours, they also use the same top-most style you are using.
if there was a way to always be above other topmost windows they would have used it too rendering it useless (because the authors of the other apps are just as concerned about the user missing their "super important" notifications as you are about them interfering with your full screen app).
You can try and play dirty tricks to force your window to the top of the top-most z-order, but those popups are likely to use the exact same tricks, again making this all useless (and as an extra bonus all those dirty tricks can turn your app into a compatibility nightmare).
You can disable these balloon notifications using these steps:
Click Start, Run and type regedit
Navigate to the following subkey:
HKEY_CURRENT_USER\Software\Microsoft\Windows\CurrentVersion\Explorer\Advanced
In the right pane, create a DWORD value named EnableBalloonTips
Double-click the new entry, and give it a value of 0.
Quit Registry Editor.
Log off Windows (this is not very cool...), and then log back on for the changes to take effect.
if you need help in how doing this by program, don't hesitate to ask ;)
I don't think that you can block all the popups, windows might not let you do that. But you can try with SetWindowPos function and pass it HWND_TOP parameter. It might work a little better than Topmost = true.
I used a sys tray popup control on my personal project SvnRadar written in WPF.
The control is at the http://www.hardcodet.net/projects/wpf-notifyicon written by Philipp Sumi.
Very nice.Only thing you will be need to "detach" it from the SysTray screen coordinates and
make it appear where you wish.
Hope it helps.
Good luck.