I was wondering how to resize a Clipping path dynamically when resizing the window. Right now I'm taking a rectangle in Expression Blend that resizes with the window. Applying this rectangle to a circle as a clipping path makes the rectangle fixed, and it won't resize anymore.
I've seen different ways of making clipping paths in XAML, in the Clip="" property as well as style markup. But I haven't succeeded yet in finding a proper XAML solution.
Can anyone point me in the right direction?
Thanks!
I was searching for an answer to the the same question (that's how I found your post) and I came across this:
http://chriscavanagh.wordpress.com/2008/10/03/wpf-easy-rounded-corners-for-anything/
Not sure it will work for you if you have a more complex shape that you would like to use as the clipping path, but if you are just looking to round some corners that will scale automatically, I suggest you check it out. It uses a VisualBrush bound to a border element instead of a clipping path. So far I have found it to be a pretty elegant solution for my needs.
Related
this is my fist question here,
but I didn't find a real answer to my question.
I work on a visualization program and use C# and WPF.
I need to draw a treemap. I actually create Rectangle objects and then add them to the Canvas which works really nice and is very useful, since I also add event handlers to those rectangles (mouse click).
I have a problem with the performance though.
When I add the rectangles and set the Stroke property (SolidColorBrush) the whole process is slowing down extremely. Without those strokes set the speed is ok.
I already improved the performance a little by adding Rectangle objects to a newly created Canvas object and then adding this new Canvas object to the original Canvas object (so not all rectangles are direkt children of the original Canvas, which should help speeding things up).
So my question is how it is possible to add a Stroke to all those Rectangles without breaking the speed.
You can find a comparison of the 'strokeless' and 'stroked' treemap versions in the links.
Treemap without Strokes
Treemap with Strokes
Thank you very much for your help!
edit:
Ok, I have found a solution!
Sorry for writing here first, but I already searched for hours to find a solution but now I found out tht the problem was my used SolidColorBrush!
I have something like this:
public static SolidColorBrush TreeMapBorderBrush;
And I use this Brush to set the Stroke property of every Rectangle that should be added to the Canvas. But exactly that was the problem.
The code looked like this before:
rect.Stroke = Visualization_Helper.TreeMapBorderBrush;
I changed it to this now:
rect.Stroke = Visualization_Helper.TreeMapBorderBrush.Clone();
So I only work with a copy of that Brush on each Rectangle now, which speeds up the processing like there was no Stroke (like in my question)!
Just for your information! Weird!
So I realize that I am venturing outside of the intended use of a Canvas here and will likely have to come up with a more manual solution. However, not being overly experienced in WPF I was hoping that there may be some solution which would allow me to continue using a Canvas control and the features it gives you for free.
The issue revolves around a Canvas which is used to zoom in and out of an image and some number of child controls that belong to the Canvas. These child controls are to be placed at various positions on the image and, as such, the Canvas works nicely in that it handles all of the layout/positioning for me as I zoom in or out.
However, one drawback is that the Canvas scales these child controls up as I zoom into the image, causing them to become too large to be usable in practice. What I am looking for is a solution that allows me to zoom into an image that belongs to a canvas without also zooming up the size of the child controls, preferably handling the layout for me.
I have tried modifying the width and height of these child controls as the zoom factor increases or decreases, but there is a slight lag time and it all looks a bit 'jerky'.
If it comes down to it I will simply do all of the zooming/panning/layout myself, but I thought I would ask first just to make sure that I am not missing anything that would allow me to tell the Canvas to not scale the size of certain controls. Thanks in advance.
You can bind the children's RenderTransform to the inverse of the Canvas' transform, see my answer to this similar question on rotation.
This is more of a thought than an answer, but what if you set a transform on the element that you did not want scaled that was the opposite of the canvas itself. So for example, if the canvas had a scale transform of 2.0, set the element to have a scale transform of 0.5. You could probably accomplish this by binding the transform values together using a value converter.
You'll probably want to make sure the element has a render transform origin of 0.5,0.5 so that it scales from the center.
I got a canvas which has many uiElements as its children.
When i get the xaml and paste it in Expression blend it displays it well.
Now when i select a path in blend and resize it by dragging the height of it grows successfully increasing the width and the rest of the coordinates are automatically calculated.
I need to give this kind of functionality to my users for the elements on my canvas.
Just wondering if any one has any suggestions or links which can help me.
Thanks
N
You want to look at the Adorner Framework of WPF. That article gives an overview and is a good place to get started.
Here is an Adorner sample that probably does what you want.
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.
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.