I have this <Path> element in a xaml file. I would like to create a copy and flip it horizontally so that the shape will point in the other direction. The <Path> has a really long Data field so I was wondering if there was a way to flip one of the elements instead of just eyeballing the element and manually making it appear the same shape and size.
I looked into flipping the image programatically using RenderTransform and ScaleTransform, but I am afraid it might hinder the performance of the application especially during a window resize.
References: https://learn.microsoft.com/en-us/dotnet/framework/wpf/graphics-multimedia/transforms-overview
Is there a protocol or way I can translate the Path element's Data
field into its horizontally flipped opposite in a way that wonder hurt
the performance of the application?
If you want to mirror the shape you might want to try this:
<Path data= "...">
<Path.RenderTransform>
<ScaleTransform ScaleX="-1.0"/>
</Path.RenderTransform>
</Path>
This doesn't really hurt the performance, since all rendered elements are transformed at some point anyway.
Related
I need to write text in the orientation specified for the image below. The fact is that I saw some examples around here by using a textblock and rotating the angle of the control using "RenderTransform", but this is not what I really need. I tried to do it using an image but it doesn't fit very well... so I really don't know how to solve it. If you look at the image beside you can see that the text is written from bottom to top and the line below the text is in the right of the screen.
This is the screen that I need to develop:
I tried by rotating the textblock, but the only way that it works for me was wrapping the text, but this is just the "closest" solution that I found. Also, as you can see, I need to set a border for the textblock.
Anyway, I hope you can help me because any example around fits with my problem.
In order to rotate your text at 90 degrees, I believe that you will need to use the LayoutTransform instead of the RenderTransform:
<TextBlock Text="FootRoller" HorizontalAlignment="Center" VerticalAlignment="Center">
<TextBlock.LayoutTransform>
<RotateTransform Angle="-90"/>
</TextBlock.LayoutTransform>
</TextBlock>
The difference is when the transform will be applied. Using the LayoutTransform, the text will be rotated before the layout pass and this will be important in your case. I imagine that using the RenderTransform will rotate your TextBlock, but as it does that after the layout pass, it would not show it all... this is because it was measured for size before it was rotated.
You can find out full details from the Transforms Overview page on MSDN. From the linked page:
LayoutTransform – A transform that is applied before the layout pass. After the transform is applied, the layout system processes the transformed size and position of the element.
RenderTransform – A transform that modifies the appearance of the element but is applied after the layout pass is complete. By using the RenderTransform property instead of the LayoutTransform property, you can obtain performance benefits.
They're all right. RenderTransform should be all you need. Like;
<TextBlock Text="FootRoller" RenderTransformOrigin="0.5,0.5" HorizontalAlignment="Center" VerticalAlignment="Center">
<TextBlock.RenderTransform>
<CompositeTransform Rotation="-90"/>
</TextBlock.RenderTransform>
</TextBlock>
P.S. - You can literally just change RenderTransform to LayoutTransform which Sheridan has provided an explanation for in his answer.
If RenderTransform didn't work, take a look at LayoutTransform. You didn't tell us why RenderTransform didn't work but it's usually a safe bet that LayoutTransform will solve whatever problem it gave you.
I have this problem.
So I have a bunch of data that must be visualized on a canvas (say more than 5000 items). So I draw them as a bunch of vertical rectangles over a horizontal line, some thing like this:
---|--|||||---|---|||---||----|||||||--------
Now, because the canvas is small, I only draw a different amount of rectangles at different zoom level. So if I zoom in more, the line get longer, and more rectangles I can see.
Problem is every time I zoom in, I have to clear the whole canvas, and redaw everything with the new zoom scale. And it is really suck, the drawing is slow and scaling not really nice.
So I wondering is there a way I can achieve a faster drawing, and good zooming (like those vector graph, you can zoom in unlimited)??
Have you tried ScaleTransform Class?
<Canvas.RenderTransform>
<ScaleTransform ScaleX="2" ScaleY="2" />
</Canvas.RenderTransform>
See How to: Scale an Element too. For performance reasons:
Freeze your Freezables.
Update Rather than Replace a RenderTransform
You may be able to update a Transform rather than replacing it as the
value of a RenderTransform property. This is particularly true in
scenarios that involve animation. By updating an existing Transform,
you avoid initiating an unnecessary layout calculation.
Have you looked at the ZoomableCanvas? I haven't used it, but it looks like it's designed to do exactly what you want.
I was wondering what is the best way to flip an element horizontally in silverlight.
What I've tried so far:
1- Scale transformation: the problem this approach has is that I need to hardcode the width of the element to translate it after setting scale=-1; this makes it hard to implement (for many elements)
<ScaleTransform CenterX="240" ScaleX="-1" />
2- Plane projection: the problem with this one is that even mouse gestures are reversed! this makes it so impossible to use.
<PlaneProjection RotationY="-180" />
[NOTE] By reversed mouse gesture I mean: when applying plane projection, then dragging mouse to left is interpreted as dragging to right and vice versa.
Any suggestion? Or is there anyway in (1) to say CenterX="50%" ?
All you need to do is to set <uiElement RenderTransformOrigin="0.5,0.5"/>. Your scale transform will not need translation after that.
Wpf hit testing is pretty good but the only method I found to extend the hit zone is to put a transparent padding area around your object. I can't find any method to add a transparent area arround a Path object. The path is very thin and I would like to enable hit testing if the user clicks near the path. I can't find any method to extend the path object with a transparent area like the image below :
alt text http://img175.imageshack.us/img175/6741/linepadding.png
I tried to used a partially transparent stroke brush but I ran into the problem described here : How can I draw a "soft" line in WPF (presumably using a LinearGradientBrush)?
I also tried to put an adorner over my line but because of WPF anti-aliasing algorithms, the position is way off when I zoom in my canvas and interfere with other objects hit-testing in a bad way.
Any suggestion to extend the hit testing zone would be highly appreciated.
Thanks,
Kumar
Path.Data is a geometry object. The Geometry class has several methods that can help you hit test with tolerance:
GetFlattenedPathGeometry(Double, ToleranceType)
GetOutlinedPathGeometry(Double, ToleranceType)
GetRenderBounds(Pen, Double, ToleranceType)
I think GetRenderBounds will work best for you.
Once you have the geometry (plus a little width) you can call
geometry.FillContains(Point, Double, ToleranceType)
or
geometry.StrokeContains(Pen, Point, Double, ToleranceType)
Out of all of that you should tune the desired hit from your hit test;
You can wrap the Path inside a transparent Border.
In WPF you can create another path with its geometry databound to the first (using Element Binding), but with transparent brush and increased thickness.
Something more or less like this:
<Path x:Name="backPath" Data="{Binding Data, ElementName=mainPath}" StrokeThickness="10" Stroke="Transparent"/>
<Path x:Name="mainPath" Data="{Binding DataFromViewModel}" StrokeThickness="1" Stroke="Red"/>
Note that the main path comes after in XAML, so that it is rendered on top.
How can you relatively position elements in WPF?
The standard model is to use layout managers for everything, but what if you want to position elements (on a Canvas, for example) simply based on the position of other elements?
For example, you may want one element (say a button) to be attached the side of another (perhaps a panel) independent of the position or layout of that panel.
Anyone that's worked with engineering tools (SolidWorks, AutoCad, etc.) is familiar with this sort of relative positioning.
Forcing everything into layout managers (the different WPF Panels) does not make much sense for certain scenarios, where you don't care that elements are maintained by some parent container and you do not want the other children to be affected by a change in the layout/appearance of each other. Does WPF support this relative positioning model in any way?
Instead of putting (as in your example) a button directly on the canvas, you could put a stackpanel on the canvas, horizontally aligned, and put the two buttons in there.
Like so:
<Canvas>
<StackPanel Canvas.Left="100" Canvas.Top="100" Orientation="Horizontal">
<Button>Button 1</Button><Button>Button 2</Button>
</StackPanel>
</Canvas>
I think that it's quite flexible when you use more than 1 layout in a form, and you can create pretty much any configuration you want.
Good question. As far as I know, we need to have a different custom panel to get this feature. Since WPF is based on Visual Hierarchy there is no way to have this sort of Flat structure for the elements in the platform.
But Here is a trick to do this.
Place your elements in the same position and give relative displacement by using RenderTransform.TranslateTransform. This way your TranslateTransfrom's X and Y will always be relatuve to the other element.