I want to be able to see a drop shadow, but not the object that is creating the drop shadow.
The code below will only work if I give the ellipse a fill colour.
<Ellipse Width="640" Height="640">
<Ellipse.Effect>
<DropShadowEffect Color="Cyan" BlurRadius="60" />
</Ellipse.Effect>
</Ellipse>
This makes sence as an invisible object wouldn't have a shadow. But, what if I really wanted it to? Is there a way to make this happen?
Are you looking for this? Or are you expecting the entire shadow to appear? If later, did you try making the ellipse transparent by setting the alpha value to zero?
Related
This post is about the controls contained within a WPF Border control. It's also about having a border that can appear and disappear without affecting the contained controls.
For the record, I'm using C# and WPF and most of the view stuff is using XAML. I also use MVVM although I'm not sure that's going to be related.
What I had planned for was a border around a control that I could make appear and disappear, for the effect of a highlight or something like that. But when I change certain properties of the Border, for example the Opacity or Visiblity, they impact on the contained controls. I have also tried changing the Background property to Transparent and that has not made a difference.
I do know that some controls have a Border property, but that's not really the case for my situation.
How can I do this?
Thanks
Try this:
<Grid>
<Border BorderThickness="2">
<YourControl />
</Border>
<Border Opacity="0.5" BorderBrush="Red" BorderThickness="2" />
</Grid>
This way you can change the opacity of the second border without affecting your control. The trick is that Grid ensures that both elements inside it have the same dimensions.
Also notice how your control is wrapped in another border with the same thickness but with no brush. This is to keep the second border from obscuring your control.
I know the WPF brush class has an Opacity property. We have a need to use a system-defined brush but with half the opacity. We'd like to do something like this (this is obviously fake code)...
<Border Background="{DynamicResource {x:Static SystemColors.HighlightBrushKey}, Opacity=0.5}" />
We of course can't change the opacity on a system-defined brush directly because that would mess up everywhere it's used.
What we'd like to do is to somehow define a converter which we take one brush and returns a copy of it with the opacity changed, but since this isn't a binding, we don't know where/how to apply a converter. Plus, if it's a dynamic resource, we need to make sure it tracks changes.
We also can't simply set the opacity on the Border directly either as then all of its children also have the same reduced opacity.
Our current work-around is instead of putting the content directly in the border, we put the border and its contents as siblings in a grid, then we do set the opacity on the border. Since the content is now on top of, instead of inside the border, it isn't affected by the opacity. It just means we've added extra stuff into the visual tree which is annoying, but it does work. It would be much better if we could simply adjust the opacity of a (copy of a) system brush right in the XAML.
A bit late, but for the sake of others...
You can create derivative solid color brushes with new opacities. To do this you simply borrow the color from the original brush used as the binding source, then set a new opacity.
<SolidColorBrush Color="{Binding Color, Source={StaticResource blue-light}}" Opacity="0.5" />
Maybe you could try creating a new brush based on the system color in stead of using the system brush directly, like this:
<Border>
<Border.Background>
<SolidColorBrush
Color="{DynamicResource {x:Static SystemColors.HighlightColorKey}}"
Opacity="0.5" />
</Border.Background>
</Border>
Well, I think I found it! Thanks to other work I've done, I came up with a DynamicResourceBinding concept (StaticResourceBinding too!) which you can use a converter to transform the brush in any way you want.
Here's a link to that page here on StackOverflow where I do this for both Dynamic and Static resources...
Post 33816511: How to create a DynamicResourceBinding
I want to get a window like this
How should i get this and i am confused between Border and Rectangle in XAML.
Border is a container control aos its use is pretty simple to get, what is the use of ractangle as it can't contain any control in it.
Kindly help
Neither Border nor Rectangle will achieve this, you probably need a Path or something similar.
I would like to answer your last question
What is the use of ractangle as it can't contain any control in it.
Yes it can't contain any controls, but you can always draw it in the background
<Grid>
<Rectangle/>
<TextBlock/>
</Grid>
The user will propably don't see any difference. Why having two different Controls for that? Not sure, but my guess is that a Border is a shortcut to have a rectangle around a control, there might be more behind it, but thats how i see it. Also a Rectangle is a Shape, and it makes sense to have a Rectangle besides an Ellipse, Line etc.
You can draw a plygon as follow:
<Polygon
Points="100 50, 100 150,250 150, 250 75, 225 50"
Stroke="Black"
StrokeThickness="2">
<Polygon.Fill>
<SolidColorBrush Color="White"/>
</Polygon.Fill>
</Polygon>
Here you can find some other interesting example
This path is like your shape, if you use Expression Blend you can draw it into the editor.
<Path Data="M20.5,0.5 L153.81876,0.5 194.5,41.181242 194.5,103.5 C194.5,114.54569 185.5457,123.5 174.5,123.5 L20.5,123.5 C9.4543047,123.5 0.5,114.54569 0.5,103.5 L0.5,20.500004 C0.5,9.4543067 9.4543047,0.50000197 20.5,0.5 z" Fill="#FFF4F4F5" Stretch="Fill" Stroke="Black" HorizontalAlignment="Left" Height="124" VerticalAlignment="Top" Width="195"/>
Lets say I have a canvas defined to be 1000x1000 big. Is it possible to only show a 100x100 part of it in a Viewbox(or a rectangel)?
Any help is apreciated.....
If you work with Brushes, you might want to take a look at Viewbox and Viewport in WPF
Edit: I just realised that Viewbox and Viewport are used for Brushes
This is not really appropiate in your situation. I looked it up, and I think you will like the Clip property on UIElement.
Since Canvas is also a UIElement, you can use the Clip property to simulate a viewport on your Canvas..
Click here for some simple Geometry types
I think you would suffice with a RectangleGeometry
<Canvas>
<Canvas.Clip>
<RectangleGeometry Rect="50,50,25,25" />
</Canvas.Clip>
</Canvas>
Edit #2:
Hehe ok.. if you want your total Canvas displayed, only smaller, perheps you should take a look and LayoutTransform. Then use a ScaleTranform to resize your Canvas ;).
<Canvas>
<Canvas.LayoutTransform>
<ScaleTransform CenterX="0" CenterY="0" ScaleX="0.5" ScaleY="0.5" />
</Canvas.LayoutTransform>
</Canvas>
Tweak the parameters until you receive the desired effect ;)
Is it possible with WPF to create a window that has the shape of a circle and uses a playing movie as the background?
To make a non-rectangular window, you need to first do three things.
Set Window.WindowStyle to WindowStyle.None
Set Window.AllowsTransparency to True
Set Window.Background to Transparent (or {x:Null})
Now, your window is completely transparent. You can use the other tips in this thread to paint a piece of media onto the window's geometry.
You should just need to throw something like this in your xaml:
<Ellipse Height="80" Width="80">
<Ellipse.Fill>
<VisualBrush TileMode="None">
<VisualBrush.Visual>
<MediaElement Source="myMovie.wmv" />
</VisualBrush.Visual>
</VisualBrush>
</Ellipse.Fill>
</Ellipse>
Actually making the window round would be more difficult. Have a look at this if you want the window to be round, it should help figure that part out.
HTH
Don't use AllowsTransparency, it has very poor performance and a lot of compatibility problems, go to this link for alternatives:
http://blogs.msdn.com/wpfsdk/archive/2008/09/08/custom-window-chrome-in-wpf.aspx
EDIT: there is an example there how to use SetWindowRgn to get rounded corners for a rectangular windows, if you pass an ellipse region instead of a rounded-rect region you will get an elliptic window, it's easy to create a region for any shape you can imagine.
you can have a canvas as your parent container (set to transparent) then add a circle with a media brush as it's background. that should do it. :)