How to Resize Controls in silverlight - silverlight

I am working on a Silverlight application and my problem is like this: I have a StackPanel
and inside the stackpanel I have a ViewBox. Inside the viewbox I am adding images and rotating them 90 and/or -90 degrees.
When rotated, my images go out of the viewbox. How can I fix this?

Use something other than StackPanel, it doesn't resize.

There's a control in the Silverlight Toolkit that addresses this problem called the LayoutTransformer. It ensures that when you change the transform, the bounds of the control are within the LayoutTransformer bounds.
You can see this at work in the Silverlight Toolkit demo. Just scroll down the tree on the left to the Layout section.

Related

image gallery with scrollviewer - wrap panel does not respect boundaries of scroll viewer

I'm trying to create a gallery-style layout with a ScrollViewer and a WrapPanel in WPF, but the WrapPanel is extending beyond the boundaries of the ScrollViewer. I've tried setting the HorizontalAlignment and VerticalAlignment properties of the WrapPanel to "Left" and "Top" respectively, but it still doesn't stay within the boundaries of the ScrollViewer.
I've also tried setting the height of the WrapPanel to specific values and set the MaxHeight properties of the WrapPanel to limit the size, but it still doesn't stay within the boundaries of the ScrollViewer, and is no longer scrollable. I've also tried wrapping the WrapPanel inside a Grid and set the height of the Grid to the size I want and set the ClipToBounds property of the Grid as "True", but it still doesn't work.
I'm not sure what else I can do to keep the WrapPanel within the boundaries of the ScrollViewer. Can anyone help me figure out how to contain the WrapPanel within the ScrollViewer?
This is my xaml code:
<ScrollViewer Grid.Row="0">
<WrapPanel x:Name="Preview_WrapPanel"></WrapPanel>
</ScrollViewer>
and this is my result in my app, in the beginning, the distance from top is correct but the bottom not. I scrolled a little up to show that the height is not respected in the top region as well:
the width is respected, but i think only because this is the application width.
The thick red border is the area, which the scrollviewer occupies. The wrappanel should be contained inside, kind of like a window, where you can only see whats behind the window and not the trees behind the wall.
the wrappanel gets filled with WebView2 Media, each image around 200x200px:
WebView2 media = new WebView2();
media.Source = new Uri(nftFile.FullName);
media.Width = 200;
media.Height = 200;
this.Preview_WrapPanel.Children.Add(media);
I use Webview2 because the content could pretty much be anything, image, video, pdf, whatever. Also it supports webp
For now though, im only adding images.
There was a known bug with webview2 and it seems it has not been fixed.
Basically, renders on top so cannot be clipped.
https://github.com/MicrosoftEdge/WebView2Feedback/issues/2579
https://github.com/MicrosoftEdge/WebView2Feedback/issues/286
You need a different plan.
Maybe ensure it doesn't matter when they don't clip.
Maybe use images.
Or hope it gets fixed soon.
Andy was correct, this is a known issue. Microsoft knows about it since .net framework Times (>10 years) but refuses to fix the issue so far.
I solved the issue by Installing the Nuget Package CefSharp which uses the chromium engine as well.
What a pitty.

WPF Animation on scrollviewer children clipped by scrollviewer

Hey folks, I'm hoping I have a fairly simple problem that can be fixed easily as it seems like I'm just missing something basic from the WPF world. I have a scrollviewer wrapping a stackpanel which contains several images, these images have animations to increasing in size when the mouse passes over them. All works fine without the scrollviewer, now I've added the scrollviewer, the animation works but only inside the scrollviewer; the increasing size isn't being allowed to overlap the scrollviewer.
Is there a way to fix this?
Thanks,
Becky
It's the way ScrollViewer works. Basically it always clips to bounds even if you set ClipToBounds="False" on it.
To make it work and continue using ScrollViewer you'll have to animate images on top of it, not inside.

WPF Adorner Transforms

I am building a control, where the user can "draw" resizable rectangles that are laid over the content. To resize those rectangles, I use an Adorner on top of them which contains 4 Thumbs to change the size of the rectangle.
The problem is, that this control is is "zoomable", meaning a ScaleTransform is applied to the whole control depending on a zoom factor. The Thumbs in the Adorner are affected by this ScaleTransform as well.
But I need them to keep their size, independent of the zoom factor.
I tried putting the Adorners in a Layer of another non-transformed control instead of the rectangle-layer, but this didn't work.
How can I achieve this?
Thanks,
Andrej
Have you checked this post: Transformations on AdornedElement are also applied to Adorner?! ? Does it work?
I also find this question on MSDN: How to exclude scaleTransform from GeneralTransform in Adorner GetDesiredTransform method., this is good because also there is some example code.

WPF and Silverlight controls and layouts pan and zoom capabilities

I would like to understand the general requirements for WPF/Silverlight layout for making it possible to implement pan&zoom (drag and zoom) features. I don't mean pan&zoom for an image but for a total page (window) layout (or part of it) with some controls.
What features of the layout and what features of used custom controls make layout fixed and pan&zoom impossible?
General rule
With few exceptions, everything in WPF can be panned, zoomed, rotated, stretched, etc to your heart's content. This include single controls like Button, compound controls like ListBox, and containers like StackPanel.
The exceptions
Here are the exceptions:
If you are using Adorner and your AdornerDecorator is outside the panned/zoomed area, then the Adorners attached to your panned/zoomed area will pan but not zoom. The solution is to put an additional AdornerDecorator inside the panned/zoomed area.
If you use a Popup, it will display at the panned/zoomed location of its PlacementTarget but it will not itself be scaled. It will also not move as you pan the area containing its PlacementTarget (basically it sits in its own surface above the target control). To get around this, use a zero-size Canvas with high Z order instead when you want something to pop up within the zoom/pan area.
Any ContextMenu you define will be shown inside a popup, so the menu items will display normal size even when the area you clicked on is zoomed in or out. Because of the nature of a context menu, this is probably desirable behavior. If not, you can wrap the menu items in a ViewBox and tie the zoom to your main area's zoom.
Your ToolTips will display normal size even if the UI is panned or zoomed. Same solution as for ContextMenu.
If you used WinForms integration to integrated legacy WinForms controls and UI, they will not properly pan, zoom and clip in certain situations. There is an advanced technique for working around this, where you implement the WinForms control off-screen, then using BitBlt or similar copy the image into your window as an image, and forward mouse clicks and keystrokes to the offscreen window. This is a lot of work, though.
If you bypass WPF and directly use GDI+ or DirectX, or use Win32 hWnds to display content or UI, that content or UI will not be properly panned, zoomed or clipped to the window unless you do it yourself in your interface code.
Final notes
A good WPF UI always uses panels like Grid, DockPanel, etc to lay out controls in a flexible manner so they automatically adjust to container sizes, rather than using fixed sizes and positions. This is also true for the internal contents of your pan/zoom area as well, BUT there is an exception to this rule: the outermost element in your pan/zoom area must have a specified size. Otherwise what will define the area being panned/zoomed over?
The easy way to implement pan/zoom capabilities is to adjust the RenderTransform of the outermost control in your pan/zoom area. There are many different ways to implement controls for panning and zooming, for example you could use toolbar buttons and sliders, scroll bars, mouse wheel, spacebar+drag to pan, draggable areas of panned UI itself, or any combination of these. Whichever interface you choose, just have it update the RenderTransform appropriately from the code-behind and you're good to go.
If your chosen panning mechanism is scroll bars, you might want to use a ScrollViewer and only use the RenderTransform for the zoom.
Be sure you set clipping on the pan/zoom area. Otherwise if you zoom in or pan items off the side, they will still be visible outside the pan/zoom area.
Use a MultiScaleImage or Canvas area, and place everything you need to pan and zoom in it
<Canvas x:Name="panZoomPanel" Background="Transparent">
</Canvas>
In code use make a TranslateTransform and a ScaleTransform in a TransformGroup to pan and zoom
Check out other SO post or this example or this one
In general you can treat any composite set of UI elements the same as you would treat a single UIElement so the case of an image isn't really different than doing the same for an entire application. The best way to handle zooming based on user input (as opposed to automatic scaling that Viewbox does) is applying a ScaleTransform. This can be set on a high level parent element, like a Grid at the root of a Window layout. For panning you can combine in a TranslateTransform or in some cases use a ScrollViewer to handle moving the view of the content.
One really easy way of implementing zoom in XAML is to use a Silverlight ViewBox. This zooms the XAML not the pixels. You can specify the stretch to use and the ViewBox will scale based on this (Fill, None, Uniform etc). There are some great Viewbox blog posts on the web if you search for Silverlight+Viewbox on Google.
The panning is easily accomplished with a similar mechanism to drag and drop and there are also numerous how-to blog posts on this, available via Google. Just amounts to capturing MouseDown, MouseMove and MouseUp events.

Is there a way to automagically make a canvas scroll on overflow in WPF?

Been checking the web and this site, but couldn't come up with any descent results.
Is there a way to make a canvas in WPF show scrollbars on overflow ? Been trying the scrollviewer, but can't get it to work :(
Thanks in advance..
The problem you're running into is that Canvas, unlike many WPF panels and containers, does not size to contents. That means if you add an element which goes outside the canvas boundaries it will not update it's size. Hence embedding a Canvas in a ScrollViewer will do no good unless you manually update the size of the Canvas.
It sounds like what you want is a Canvas which supports size to contents. This blog entry has exactly that control.
http://themechanicalbride.blogspot.com/2008/11/auto-sizing-canvas-for-silverlight-and.html
I took a different approach and abandoned the Canvas for Grid. The Canvas is more performant but for my purposes at least I haven't noticed a difference. The grid can mimic the behavior of canvas by doing the following.
Create a single row,single column grid.
Set the HorizontalAlignment to Left
Set the VerticalAlignment to Top
Use Margin "x,y,0,0" to set the position.
Bam..works just like canvas and it works great in a Scrollviewer.

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