I am trying to port an application from silverlight to wpf. Unfortunatley I am new to both. Is there an equvivalent to the following Silverlight code in WPF?
private static Canvas GetCanvas()
{
var uc = Application.Current.RootVisual as UserControl;
if (uc == null)
{
return null;
}
return uc.FindName("ChoiceCanvas") as Canvas;
}
Currently I am using
Application.Current.MainWindow.FindName("ChoiceCanvas") as Canvas;
But this doesn't work, perhaps because ChoiceCanvas is something located in a UserControl and not in the MainWindow?
There is no RootVisual property in WPF. As far as I understand, the "Window" is the "root". You can get the Window that any WPF (D.O.) object belongs to by running the static method Window myWindow = Window.GetWindow(myControl);
FindName won't work becuase the Canvas exists in the namescope of the UserControl, try using the LogicalTreeHelper instead.
var canvas = LogicalTreeHelper.FindLogicalNode(
Application.Current.MainWindow, "ChoiceCanvas") as Canvas;
The current window is the root visual.
From MSDN WPF Graphics Rendering Overview:
The root visual is the top-most element in a visual tree hierarchy. In
most applications, the base class of the root visual is either Window
or NavigationWindow. However, if you were hosting visual objects in a
Win32 application, the root visual would be the top-most visual you
were hosting in the Win32 window. For more information, see Tutorial:
Hosting Visual Objects in a Win32 Application.
Related
I am showing a WPF exe window inside another WPF application using winform host.
I have created a panel in main application and set it as child of winformhost.
mHostingPanel = new System.Windows.Forms.Panel()
{
BorderStyle = System.Windows.Forms.BorderStyle.FixedSingle
};
mWinformHost = new WindowsFormsHost();
mWinformHost.Child = mHostingPanel;
and then I start the other window process and set hosting panel as parent.
WindowsAPI.SetParent(mProcess.MainWindowHandle, mHostingPanel.Handle);
My question is if I launch the application,Who will be rendering my Child WPF window whose parent is a winform panel.Will it be Direct-X or GDI context of Panel?
Also if I set Allowtransparency=True on child WPF application,The UI doesnt show up in hosting panel.
Found the reason.Its called airspace issue (when win32 and WPF trying to share pixels) and I dont think it can be solved by any framework API as microsoft denied it.
https://visualstudio.uservoice.com/forums/121579-visual-studio/suggestions/2644120-bring-back-the-hwndhost-isredirected-and-compositi
Mitigating AirSpace issues
I'm writing a simple "tutorial" library that will allow developers to easily add step-by-step tutorials to their existing WPF applications. The tutorials will help first time users of the application find their way around by adding an overlay that highlights a control and explains its purpose. The end result will look something like this:
The regular application:
The overlay explaining the purpose of a control:
My question is this: What's the most reliable and unobtrusive way to inject the overlay view into the current window? The best I've come up with so far is to require the developer to add an attached property to whatever window will be hosting the overlay, and then add the necessary elements on the window's Initialized callback:
public static void IsTutorialOverlayCompatibleChanged(object sender, DependencyPropertyChangedEventArgs e)
{
if ((Boolean)e.NewValue == true)
{
if (sender as Window != null)
{
Window window = (Window)sender;
window.Loaded += new RoutedEventHandler((o, eargs) =>
{
Grid newRootElement = new Grid();
newRootElement.Name = "HelpOverlayRoot";
if (window.Content as UIElement != null)
{
UIElement currentContent = (UIElement)window.Content;
window.Content = null;
newRootElement.Children.Add(currentContent);
newRootElement.Children.Add(new HelpOverlayControl());
window.Content = newRootElement;
}
});
}
}
}
This feels like a hack, however, and I'm not sure that there isn't some edge case where this method will break the layout of the application. In addition, it requires that the window's Content property be an instance of type UIElement.
I'd like to avoid forcing developers to change their XAML (i.e, adding a custom overlay UserControl to every window) in order to use my library. What's the best way to add this kind of functionality to an existing WPF application?
To preface this question, I am working on coding the back end of an application whose UI was put together by someone else (I believe using Blend). The application consists of a series of "Screens," whose root element in XAML is "UserControl". There is no use of the "Window" tag anywhere in the source.
What I want to do is remove the Windows border that is added to the outside edge of the application when I run the program. The border currently consists of forward/backward buttons like a web browser, and an X button to close.
All I can find from searches are instructions to add
WindowStyle="None"
to the
<Window>
element. But of course, I don't have one of those, and WindowStyle is not a property of UserControl. Anyone know how to accomplish this with UserControl root elements?
Edit: The StartupUri for the application is
this.StartupUri = new Uri(#"pack://application:,,,/WpfPrototype1.Screens;Component/Screen_1.xaml");
the file it points to does not have a Window tag.
Based on the comments above it seems your MainWindow is created dynamically somewhere, however you can use the Application class to get the applications MainWindow.
var mainWindow = Application.Current.MainWindow;
And you can then set your border style from there
Example:
private void RemoveBorder()
{
var mainWindow = Application.Current.MainWindow;
if (mainWindow != null)//should never be
{
mainWindow.WindowStyle = System.Windows.WindowStyle.None; // removes top bar (icon, title, close buttons etc)
mainWindow.AllowsTransparency = true; //removes the border around the outside
}
}
I have a win form application with a MDI Form.
for some reason i used a WPF Window in my application.
so i want to ask how can i set WPF window parent to my MDI Form?
The following code should give you the ability to set the owner of the wpf dialog to your win form.
public static void SetOwner(System.Windows.Forms.Form owner, System.Windows.Window wpfWindow)
{
WindowInteropHelper helper = new WindowInteropHelper(wpfWindow);
helper.Owner = owner.Handle;
}
There is an open-source MDI implementation for WPF that you might want to look at. It may be a good bit of work and re-structuring of your code, but if you absolutely must have MDI, then that may be the best way to go forward with this - MDI for WPF.
Can we cast a WPF User Control to a form control??
I'm sorry you can't. WPF works very differently internally from Winforms: Winforms uses the controls provided by the Windows OS (where each control has a window handle), where WPF uses DirectX to do the painting.
You can host WPF controls inside winforms applications (EDIT)and vice versa (with limitations) but that is perhaps not what you're after.
I tried this out:
TouchScreenWPF touchUI = new TouchScreenWPF();
ElementHost elementHost = new ElementHost();
elementHost.Child = touchUI;
Control userControl = new Control();
userControl.Controls.Add(elementHost);
The form contains the usercontrol, but does not display anything when I include a WPF User control. It works with a single button though... Am I missing something there?