When I host WPF controls that use adorners (the error border of the textbox) in a HwndSource the adorners are not shown. It seems that the adorner layer is not there. Why is that so and what can I do against it? Is this a known bug?
The AdornerLayer is usually part of the default template of the Window class.
If you are customizing the Window template or host controls in something else than a Window; you'll have to create the AdornerLayer yourself.
This can be done by wrapping your WPF controls inside a System.Windows.Documents.AdornerDecorator:
hwndSource.RootVisual = new AdornerDecorator { Child = yourTextBox };
Related
wpf
I have a control A, (an inkcanvas), within a Grid within a ScrollViewer. Conrol A is taller then the physical window, so the ScrollViewer correctly adds a vertical scroll bar and the entire control can be viewed by scrolling down. When attaching an Adorner with a control B, (another inkcanvas), to control A, scrolling downward shows the Adorner to be cut off at the bottom of the screen. That is, the Adorner is not completely covering the adorned element and/or is not extended downward when scrolling.
How do I get the Adorner (the control) to completely cover the adorned element and respect the ScrollViewer. (I need a one-to-one match between the pixels of the Adorner control and the adorned element within the ScrollViewer).
TIA
Edit#1: The key line in the Adorner that sets the background of the InkCanvas is
_inkcanvas.Background = CreateGrid();
public InkCanvasTextAdorner(InkCanvas element)
: base(element)
{
_element = element;
_visuals = new VisualCollection(this);
_inkcanvas = new InkCanvas();
_inkcanvas.Background = CreateGrid();
_visuals.Add(_inkcanvas);
AdornerLayer adornerLayer = AdornerLayer.GetAdornerLayer(element);
adornerLayer.Add(this);
}
If an InkCanvas is used (as the above) the Adorner's background is clipped at the bottom. The adorner control, however, does continue to the bottom of the adorned element.
However, if a Canvas is used instead of the InkCanvas, the Adorner's background does extend to the bottom of the adorned element.
What's wrong?
I'm guessing that the difference in the Background property expanding past the physical screen with the Canvas and not the InkCanvas may be because the Canvas inherits from Panel whereas the InkCanvas does not. Based on the finding that the Canvas background does do what I need, I find the below code does accomplish what I want--the canvas allows images from layers beneath it to be seen yet posts a grid of lines overwhich the InkCanvas will accept strokes. All is well :)
public InkCanvasTextAdorner(InkCanvas element)
: base(element)
{
_element = element;
// The VisualCollection has only one visual parent. I.e. InkCanvasTextAdorner is the parent to the VisualCollection.
// By overriding default rendering behavior of the VisualCollection, any kind of control and its children can be placed in the Adorner.
_visuals = new VisualCollection(this);
_inkcanvas = new InkCanvas();
_inkcanvas.Background = Brushes.Transparent;
_canvas = new Canvas();
_canvas.Background = CreateGrid();
_grid = new Grid();
_grid.Children.Add(_canvas);
_grid.Children.Add(_inkcanvas);
// The _grid is a logical child of the VisualCollection of the Adorner. The ArrangeOverride and MeasureOverride will set up the Grid control.
_visuals.Add(_grid); // Adding a single control for display.
// AdornerLayer adornerLayer = AdornerLayer.GetAdornerLayer(element);
AdornerLayer adornerLayer = AdornerLayer.GetAdornerLayer(element);
adornerLayer.Add(this);
}
Which looks like:
Is there any possible way to act usercontrol as a childwindow..?
I need usercontrol will be act like childwindow... Is it possible?
You can put Usercontrol Inside Content of Childwindow.
it possible in mvvm too.
System.Windows.Controls.ChildWindow childWindow = new System.Windows.Controls.ChildWindow();
childWindow.Content = userControlObject;
childWindow.Show();
I have an ElementHost in a Windows Forms UserControl that is sized to the full width/height of the Windows Forms UserControl. The UserControl is on a Form...but I can't move the UserControl or select it in the Designer, because the Child of the ElementHost steals focus whenever I mouse over/click the UserControl in the Designer.
How can I prevent this from happening at Design time?
I did the following:
if (LicenseManager.UsageMode == LicenseUsageMode.Designtime)
{
host.Enabled = false;
}
which now allows me to drag and resize the UserControl on the parent.
I'm trying to create an overlay in wpf (with darkening background), similar to the ones you can find on the web to popup images.
I would like it to be reusable in more than 1 part of the application, with diffent types of content.
this is the temporary code of the constructor of the adorner class (just to try)
private readonly Grid _grid = new Grid();
public DarkOverlayAdorner(UIElement adornedElement, Object content) :
base(adornedElement)
{
_grid.Background = new SolidColorBrush(Color.FromArgb(99, 0, 0, 0));
IsHitTestVisible = true;
var visual = content as UIElement;
if (visual != null)
_grid.Children.Add(visual);
}
In addition in the class (of course), I have the ovverrides of MeasureOverride and ArrangeOverride to give the adorner the correct size of the adorned element, GetVisualChild, and VisualChildCount...
The problem here is that the adorner is correctly shown, but no events or behaviour are applied on the adorned element. For example:
AdornerLayer layer = AdornerLayer.GetAdornerLayer(textBoxProva);
layer.Add(new DarkOverlayAdorner(textBoxProva, new Button{Content = "prova"}));
The button here is shown, but I can-t click the button and no effects on button mouseover are applied.
I still can't figure out the problem.
Ok, I've lost a lot of time trying to figure out what was the problem.
In the end I found the solution:
If you want the element added to react to events, I think that the element must be bound to the visual tree of the adorner.
The way to do it is to use a VisualCollection, intitialized to the adorner itself:
VisualCollection visualChildren;
FrameworkElement #object;
public DarkOverlayAdorner(UIElement adornedElement) :
base(adornedElement)
{
visualChildren = new VisualCollection(this);
#object = new Button {Content = "prova"};
visualChildren.Add(#object);
}
protected override Visual GetVisualChild(int index)
{
return visualChildren[index];
}
This way the events are correctly routed.
You might want to take a look at the ChildWindow control in the Extended WPF Toolkit. It is a control that pops up a Window with a modal background effect, and you can specify the content to put inside the Window.
How to use a WPF user control in a windows forms application?
From the MSDN:
Use the ElementHost control to place a
WPF UIElement on your Windows Forms
control or form.
Example:
private void Form1_Load(object sender, EventArgs e)
{
// Create the ElementHost control for hosting the
// WPF UserControl.
ElementHost host = new ElementHost();
host.Dock = DockStyle.Fill;
// Create the WPF UserControl.
HostingWpfUserControlInWf.UserControl1 uc =
new HostingWpfUserControlInWf.UserControl1();
// Assign the WPF UserControl to the ElementHost control's
// Child property.
host.Child = uc;
// Add the ElementHost control to the form's
// collection of child controls.
this.Controls.Add(host);
}
Here is a nice tutorial how to do that.
The control called ElementHost is for
WPF in WinForms what the
WindowsFormsHost was for WinForms in
WPF. In the designer, you can find
this control in the Toolbox underneath
"WPF Interoperability".