I have a WPF application using Prism framework. It has three regions that gets loaded in shell. Now, I have a requirement for which have to display a dialog once the main window(all the regions) is loaded. i.e. dialog should display on top of main window. I tried to publish an event during shell initialization,however dialog display only when I close main window or if publish the event in one of region's usercontrol constructor, it displays the dialog first and when dialog is closed main window loads. Now, am thinking if there is any way I can find if all the regions are loaded through an event then I can publish the event there.
Questions:
1. Is there any event that I can use to detect if all the regions are loaded?
2. Is there any other approach that you can point me to to achieve this requirement?
Put this in the constructor of the parent control
Dispatcher.BeginInvoke(DispatcherPriority.Loaded, new Action(() => {code that should be executed after all children are loaded} ));
Is there any event that I can use to detect if all the regions are loaded?
Override PrismApplicationBase.OnInitialized and call the IDialogService from there.
Related
I have prism module which I loading in separate application window.
When I closing it and opening again, getting error that some region is already registered. It is child region from one of my views. To make it more clear, I have next hierarchy:
Shell
--RegionA
--View
--RegionB
--RegionC
So when I try to navigate to RegionA with View, I getting error that RegionB is already registered. I cannot complain, it is really registered on previous window load and regions wasn't removed.
I tried to add event handler to Closing event of window but at this moment IRegionManager.Regions collection is empty for some reason.
So I need a way to handle window close event and clear regions.
I'm writing a WPF application and want it to start as a hidden window. I've created the Window object and set its Visibility property to Visibility.Hidden before calling Application.Run(). Then, I have an event handler for Window.Loaded that also sets the visibility to Visibility.Hidden. Between the call to Application.Run() and the callback to OnWindowLoaded(), there is a black outline of the window that flashes up on the screen and then disappears. It's like the window manager is creating a drop shadow for the window or something and then hides it immediately.
After running my project through instrumentation, I finally found that Window.Show() was somehow getting called. So, I looked into the source code at http://www.dotnetframework.org/Search.aspx:
Application.Run() ends up calling a private method named Application.RunInternal().
RunInternal() checks the visibility of the Window object that was passed in to the Run() method.
If the Visibility property is not Visibility.Visible, a call to Window.Show() is made.
I then looked at the source for System.Windows.Window:
Window.Show() sets the Visibility property on itself (the window) to be Visibility.Visible.
Based on this, I don't see how to force the window to stay hidden. By trying to make the window invisible at startup, I'm causing the Application object to call Window.Show(); I don't understand why the Application object even cares about the window's visibility. It's been a frustrating experience... :-(
I've seen other answers that say to not call Application.Run() and to instead set up your own event dispatchers, but that seems like overkill for something that should be easy. I just want the main window to stay hidden, for no "flicker" to appear at app startup, and for the window to become visible when I'm ready for it to do so (which happens later in my application logic).
Can anyone offer a suggestion?
Did you remove the StartupUri entry in App.xaml? If you do, the App class won't instantiate the window for you and show it. You can do this by yourself by overwriting the App.OnStartup method.
Basically, I build a composition root in this OnStartup method and just create a window at the end of the process:
protected override void OnStartup(StartupEventArgs e)
{
base.OnStartup(e);
// Do your custom initialization code here
MainWindow = new MainWindow();
MainWindow.Show();
}
If you really want to omit the whole application build up process (which I wouldn't recommend, as you won't have features like the fallback to Application Resources), you can create a Dispatcher by yourself using this code:
var dispatcher = Dispatcher.CurrentDispatcher;
var synchronizationContext = new DispatcherSynchronizationContext(dispatcher);
SynchronizationContext.SetSynchronizationContext(synchronizationContext);
Dispatcher.Run();
The comment on this Answer finally led me to find the solution to this issue. I needed to display multiple windows on multiple screens at once, and by minimizing the window it gives me the performance I needed. Thanks.
I have a WPF window myWindow, which I open using myWindow.ShowDialog() ?? true and listen to the DialogResult (DialogResult = true) to execute some code.
When I set it to either true or false, the window is disposed, is there a way I can prevent this window from closing while also getting the DialogResult? Also, is there a another way I can approach this problem?
What do you want to happen? For example:
You might want a modal dialog (so users can't interact with the rest of the UI while it is visible) but you want code to run in the main program in response to some user action in the dialog. In this case, add events to your dialog that the main program can respond to.
Or you might actually want a modeless dialog, which lets users interact with the rest of the program without completing the dialog. In this case, don't use ShowWindow, just show an owned window.
I have a button in a Window that needs to call a function in pages contained within a frame. The page inside the frame will change based on a navigation contained in the main Window, so I will know the current Page within the frame.
Can someone help with how to call function in frame pages?
If you wish to approach this from an MVVM perspective, you'll want to make sure you're not working with the actual view here, but the ViewModel abstraction of it. In that case, your parent Window is probably backed by a ViewModel that contains some sort of a collection that backs your pages in the frame/tab control/container of choice. In that case, the button should link to a command on your Window-backing ViewModel and use the selected item in the collection to access the function. If you do not have a direct reference in this fashion (for example loading in from another module or something for frame contents) you can also use EventAggregator from the Prism/CAL libraries and publish an event when the window button is pressed and set up your pages to receive that event and handle the call there. EventAggregator can be a slick way to handle cross-module logic in a clean way.
I have Two WPF window Window1.xaml and window2.xaml.
In window2.xaml.cs i have one function which does some complex calculation and display intermediate resuls on a TextBlock.
Now What i want.
by clicking on button of Window1.xaml i want to open Window2.xaml as a dialog box and want to execute complex function of windows2.xaml.
If i call complex button on Window2.xaml' load event then dilog box apear after execution of complex function.
How to do this by Threading.
You need not open the window in a thread. Once you've opened Window2, start a thread for the complex function in the Window2.Loaded event handler. This will leave your UI undisturbed.
Opening a Window in a thread that is not UI thread is not recommended at all. You can open a popup window using Show() (modeless) method or ShowDialog() (modal) method. In Window2's load method, you can start a new thread which does a complex operation and once it is done with the operation, it can show a dialog.
Now, while in a different thread than UI thread, if you want to show any UI (dialogs, windows) or change existing UI (textblock, etc), you must use Dispatcher.Invoke method.