In my WP7 app, I have a user control, with a grid, and an ellipse in the layout root:
<Grid x:Name="LayoutRoot">
<Grid x:Name="grdCircle">
<Ellipse x:Name="elCircle" Stroke="#FFB91515" Margin="5"/>
</Grid>
</Grid>
I drop this on my main page in the WP7 app, and it looks fine in landscape mode, but when I switch to portrait the width expands and the height contracts, so it is no longer a circle. What I want is for the circle to be the max size it can be regardless of the orientation and still stay a circle.
I've tried putting SizeChanged event on LayoutRoot, and setting the grdCircle width/height to whatever was smaller - the LayoutRoot actual width or the LayoutRoot actual height, but as soon as I do that, changing the orientation doesn't fire the SizeChanged event of LayoutRoot anymore because LayoutRoot also becomes smaller. How can I ensure that my ellipse is always a circle and grows/shrinks based on the orientation?
Edit:
By default, the LayoutRoot grid should have horizontal and vertical alignment set to stretch with margins of 0, so shouldn't the LayoutRoot grid always grow to the size of its container?
Maybe you should take adventage of OrientationChanged event of a Page?
Updated
I think that your control is filling all space that is available. If you change orientation then the amount of space is changing - as a result your control is not a square any more. That fact implicates that the ellipse changes its shape from circle to ellipse, because your ellipse is also trying to fill in all available space. To avoid this you can set Stretch property of an ellipse to Uniform. This should resolve your problem.
Related
I am trying to load an image within a canvas such that, if the size of image overflows the canvas, the scroll bars should get activated (MS Paint style)
<Window>
<ScrollViewer>
<Canvas ScrollViewer.HorizontalScrollBarVisibility="Visible"
ScrollViewer.VerticalScrollBarVisibility="Visible">
<Image Source="SampleImage.jpg" />
</Canvas>
</ScrollViewer>
</Window>
Now as Canvas is stretched to Window's size, scroll-bars won't appear as Canvas is not actually overflowing out of the Window.
Secondly, as the Image is much bigger than the Canvas, it is getting clipped at the bounds of Canvas, so ScrollViewer doesn't think that its content: Canvas is actually overflowing.
It happens a lot of time with StackPanels too, that even though the bound data has tens of rows, but still the scrollbars don't get activated. Sometimes scrollviewers appear as mystery to me.
So, what should be the basic logic kept in mind when using ScrollViewer control.
Thank you.
Edit: Just edited the question title, so that whosoever has problem with canvas can get this question easily in search.
From MSDN:
Canvas is the only panel element that has no inherent layout characteristics. A Canvas has default Height and Width properties of zero, unless it is the child of an element that automatically sizes its child elements. Child elements of a Canvas are never resized, they are just positioned at their designated coordinates. This provides flexibility for situations in which inherent sizing constraints or alignment are not needed or wanted. For cases in which you want child content to be automatically resized and aligned, it is usually best to use a Grid element.
Hovever, you can set Canvas Height and Width explicitely:
<ScrollViewer Height="100" Width="200">
<Canvas Height="400" Width="400">
//Content here
</Canvas>
</ScrollViewer>
Maybe one of these two Links might help you:
Silverlight Canvas on Scrollviewer not triggering
ScrollBars are not visible after changing positions of controls inside a Canvas
I am creating an app for the Microsoft Surface. I have a WPF control rotated 180 degrees using rendertransform so that people on the other side can use it. There are two of them, one rotated, one not. When a user selects a tab on the control, the control grows to accommodate the tab size. On the one that's not rotated, the height animation works correctly, growing "upward" toward the "top" of the screen. The rotated one grows in the same direction, toward the top as well, but it need to grow on the opposite direction. Both should grow towards the center of the screen.
Setup (They are legends on a map):
<SurfaceWindow>
<Canvas>
<UserControl />
<UserControl /> // rotated
<Map />
</Canvas>
</SurfaceWindow>
Is there a way to control the direction of a height animation?
Thanks,
Andrew
You don't need two controls : just one with, say, a 'Flipped' property (or a dependency property to use it in design time). When Flipped is True, you should set the rotation on your control and the VerticalAlignment to Top. when false, no rotation and VerticalAlignment to Bottom.
Solved.
Used LayoutTransform instead of RenderTransform
eg
Legend2.LayoutTransform = new RotateTransform(180);
instead of
Legend2.RenderTransform = new RotateTransform(180);
I'm trying to implement panning within a Canvas within a scrollviewer like:
<ScrollViewer>
<Canvas>
<!-- some visual elements here -->
</Canvas>
</ScrollViewer>
I want a click and drag operation within the canvas to cause the contents of the canvas to move. I've tried handling the MouseDown, MouseMove, and MouseUp events to do a translation in the manner described here but it hasn't worked.
Any ideas?
You can't do that with your current setup. A Canvas will stretch beyond its parent container and the scrollviewer won't know the size of the Canvas (it will tell it it doesn't need to scroll) and therefore can't create the handles.
If you want to skip with that set up change the canvas to a grid and use the Vertical Scroll and Horizontal Scroll and associated set properties to move the visible section of the grid around.
Try giving your Canvas a set Width and Height and give it a background color (Transparent should be fine) and see if that helps you get your mouse events.
I'm having a problem where I have elements such as Listboxes and Rich Text boxes that I want to set to size automatically in xaml according to the size of the window, but I only want it to resize to the size of the window and then put scrollbars if the content is any bigger than that.
Unfortunately, the only way I can get scroll bars to work is if I set a specific height of the listbox/rich text box (which does not work because I want it to automatically resize to the height of the grid that it is contained within, which is generally the height of the window (auto).
Any help would be greatly appreciated.
You do not need to use fixed values for Width and Height - you should rather specify a minimum width/height for your controls using the MinWidth and MinHeight properties. Then try a layout similar to this:
<Window>
<ScrollViewer HorizontalScrollBarVisibility="Auto" VerticalScrollBarVisibility="Auto">
<Grid>
<ListBox MinWidth="500" MinHeight="250"/>
<!-- any other controls... -->
</Grid>
</ScrollViewer>
</Window>
The Grid generally uses all the space it gets if its alignment properties are set to Stretch and if at least one row/column is set to be star-sized. In this case, there are only one row and one column, implicitly created, both star-sized by default.
To make the ScrollViewer work, you need to somehow set a minimum size of your content controls because otherwise the ScrollViewer does not know when to activate the ScrollBars. In the example above, I have done that using the MinHeight and MinWidth properties of the ListBox, but you could also set these properties on the Grid's RowDefinitions and/or ColumnDefinitions.
Now, if you resize the window, so that the Width becomes smaller than 500, you will see that scrollbars will appear. Just check it out.
How do I make a Canvas stretch fully horizontally with variable width? This is the parent Canvas, so it has no parents, only children.
XAML Source: it displays in blend
http://resopollution.com/xaml.txt
Use a Grid as the top level element in your UI - it'll stretch to fill its container. Then put a Canvas with HorizontalAlignment="Stretch" inside the Grid and it'll behave the way you want.
<Grid xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation" xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml">
<Canvas Background="Blue"/>
</Grid>
That worked for me. The key is your top level UI element. While a Grid fills all available space by default, Canvases take up only as much room as their contents demand.
I'm guessing you've tried
canvas.HorizontalAlignment = HorizontalAlignment.Stretch
If this doesn't work, then what you could do is bind the Width and Height properties of the canvas to the ActualWidth and ActualHeight properties of the containing window.
You could use a dock panel to get it to fill the available width. The last item in a dock panel list of controls is automatically stretched to fill the remaining space.
<DockPanel>
<Canvas />
</DockPanel>
The canvas should do this automatically, unless you are manually setting the height and/or width. What kind of control are you trying to place the canvas on? Can you post your code?
The problem is that you're specifying the Height and Width. Without these properties, the control may appear to vanish in the designer, but it should size appropriately when you insert the canvas into another control.
If I recall correctly, the next version of WPF will have 'DesignWidth' and 'DesignHeight' properties that allow you to show the control in the designer with a given size without effecting it's measurement when inserted into other controls.