I have an application written in C# targeting .NET Compact Framework 3.5, running on Windows CE. I would like to provide a custom visual cue in a modal dialog if the user tries to interact with its owner window without closing the dialog first.
Is it possible for a modal dialog to receive notifications of mouse clicks on its owner window? The owner window is running in full screen, so it would be sufficient to trap clicks outside of the modal dialog in general.
This is how modality works. When a dialog is shown modally (CE or desktop Windows) that window gets it's own internal message pump. What that means is that wehn you get a message (like a mouse down) outside of your Window, the pump discards it. There's no way for the pump to dispatch that message "up" the chain to another pump (well not without you mucking with both pumps yourself - it's possible yes, but complex, convoluted, and not at all scalable or maintainable).
You could probably use the Control.Capture property.
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 have an application that monitors bit states from external socket/Ethernet connections, known as a PLC device.
These states trigger database calls and UI updates, some of which require Modal dialogs, others require Modeless dialogs.
The issue is that the process needs to continually monitor even when a Modal dialog is displayed.
I have tried using a DispatcherTimer, but this will block when a Modal dialog is displayed. I understand the reason why.
I tried a standard Timer, but I get an exception stating something like 'Some UI components require the thread to run in STA mode.'
So I create a standard Thread and set the ApartmetState to STA. The thread runs just fine after adding DispatcherInvoke around the part of the processing loop that requires UI interaction, but whenever a Modal dialog box is displayed, the thread is blocked until the Modal dialog is closed.
Now I really do not want to get into inter-thread messaging and over-complicating the whole thing.
I have also tried putting the Modal dialog into its own thread whenever a Modal dialog is needed. Everything works fine and it was almost acceptable, but the owner window of the application is still accessible, essentially making the Modal dialog a Modeless dialog. I tried setting the IsEnabled flag on the owner window and at first I thought that would be okay, but it is still active when clicked and hides the dialog.
Any suggestions?
I have solved the issue! I reverted back to a standard Timer and was able to get around not requiring STA mode; this reguired another judicial placement of Dispatcher.Invoke.
Now everything works as I expect.
In my project I have a MessageBox that pops up from time to time.
When I'm playing a game and the MessageBox appears, the game is minimized and I'm back to the desktop.
This might depend from app to app, but this specific app/game minimizes when MessageBox appears.
How to avoid this behavior? Is there anything I can do to the MessageBox to make it lose focus/not activated ? I tried to look at the MessageBox methods but no luck.
It sounds like you want the message box to be able to display while the rest of your code is still running. Type of messagebox you are using is modal and needs to be closed until it allows you to interact with the other open window.
I suggest you start a new thread for the message box so that the thread can continue to run allowing you to be able to interact with the other windows.
I would like to know if it is possible to SendMessage and PostMessage to/in other application even if it is not activated, or somehow to interact with that application without disturbing the user....
So far all I want to do is detect Pixels at specific coordinates than to Click on specific coordinates.
Note: Please do not misunderstood, the reason I want to detect Pixels and than Click, is because the button does not has Class ID.
It is possible to use SendMessage and PostMessage to send mouse clicks at specific coordinates to a window. The messages to send would be like WM_LBUTTONDOWN, WM_LBUTTONUP, and WM_LBUTTONDBLCLK. These messages can be sent with the window minimized or hidden.
If you have Visual Studio, there is an included application called Spy++ (and Spy++ 64 Bit). If you use those programs and have them monitor the window messages to your target application, you can see the exact window messages that are sent when you manually click on the button.
It is difficult if not impossible to detect pixels when the window is not visible either due to being minimized, hidden, or just covered by another window. If the application will be running in Vista or later, you might try creating a DWM Live Thumbnail of the application inside your app and scanning the pixels from there to determine the button's location.
Hopefully this information will get you started or at least let you know how complicated this may be so you can make an informed decision to continue or not.
In my application (C#, Windows Forms) I have got a telephone information screen: if there is an incoming phone call a window with additional information to the caller is shown.
This window should open in foreground and should stay there even if the user is writing in another window (so the user still sees the information regarding the incoming phone call).
First I've used BringToFront - but this didn't really work in all circumstances (e.g. when the main application was not in the foreground).
Right now I am using BringToFront and the user32.dll function BringWindowToTop -> which works, but if the window loses focus it is in the background.
How do I implement this behaviour ?
I think you want to set your form as TopMost:
yourForm.TopMost = true;