I have a sample app with a MultiScaleImageControl. By default it fills the available ViewPort width. How can i make it use the available height?
Edit (Copy from comment)
It's nothing more than
<Grid x:Name="LayoutRoot" Background="White">
<MultiScaleImage HorizontalAlignment="Left" Name="multiScaleImage1" VerticalAlignment="Top" />
</Grid>
My question doesn't aim at the width of the control itself, but at the displayed MultiScaleImage...
I would recommend that you remove the VerticalAlignment property. In fact get rid of the HorizontalAlignment as well. This lets the containing grid size the control for you.
You may also be seeing the control simply maintaining the aspect ratio of the image. If the image is wider than its high then at zoom level 1 the image will not fill the entire height.
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'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 get the width available for the children of a scroll viewer in XAML? Thanks.
There's no direct way of doing this that I know of, since WPF automatically passes the available space in to the child controls' Measure() function so that they size to fit the available space.
Note that, by default, it passes in infinity for the vertical direction, since content can scroll forever vertically. You can change the visibility of the scroll bars in both the vertical and horizontal direction to affect whether infinity is passed vertically, horizontally, or both.
The best way of figuring out how wide the child controls actually have to layout in pure XAML would be to create an empty control - for instance, an empty grid - and then bind to its ActualWidth property:
<ScrollViewer>
<StackPanel>
<Grid x:Name="MeasureGrid"/>
<TextBox Text="{Binding ElementName=MeasureGrid, Path=ActualWidth}"/>
</StackPanel>
</ScrollViewer>
Aside from displaying the width that is actually available to controls, I don't see any other use for this information in XAML, though - all of the other scenarios I can think of can use this information implicitly. Can you give us more information on what you are trying to accomplish?
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.
Specifically, I'm looking to use the 16*16 32-bit png images included with the VS2008ImageLibrary. I've tried manually setting the Height and Width attributes of the image, adjusting margins and padding, adjusting Stretch and RenderOptions. My attempts to create toolbar buttons have all led to either Improper Scaling (blurry icons), the bottom row of pixels on the icon being truncated, or the toolbar button being improperly sized - not to mention the disappearing icons already mentioned Here. Has anyone found the best way to make standard, VisualStudio/WinForms-style toolbar buttons that display properly in WPF?
First, change the image resolution to 96DPI, this can done with the free Paint.net ( http://www.getpaint.net ) by opening the file, Selecting Image->Canvas Size from the menu and adjusting the "resolution" to 96 and saving.
If this doesn't help you can then use the solution I wrote about in my blog here http://www.nbdtech.com/blog/archive/2008/11/20/blurred-images-in-wpf.aspx
Best way would be using Vector graphics instead of png. I know the following is not exactly what you asked for, but imho there is no way for better looking icons. Also it would help you get rid off margins and paddings. (Ok, if you want to use photos you're screwed)
Bad News is you probably need to repaint all your icons. You could do this using MS Expression Blend(it's capable to save painted Images as .xaml) or you make them on our own with a texteditor.
I prefer the Border.Background instead of the Image.Source for placing the icon, this allows me to put text over the image. This would look samething like that:
<Window.Resources>
<ResourceDictionary Source="Resources/Icons.xaml"/>
</Window.Resources>
<!--
...
-->
<Button>
<Border Background="{StaticResource IconName}" Height="16" Width="16" />
</Button>
The best workaround I can come up with is this:
<Image x:Key="TB_NewIcon" Source="Toolbar Images/NewDocumentHS.png" Height="16" Width="16" SnapsToDevicePixels="True" RenderOptions.BitmapScalingMode="NearestNeighbor"/>
...
<Button Command="ApplicationCommands.New" Content="{StaticResource TB_NewIcon}" Padding="2,2,2,1"/>
Or Alternatively:
<BitmapImage x:Key="TB_NewIcon" UriSource="Toolbar Images\NewDocumentHS.png"/>
...
<Button Command="ApplicationCommands.New" Padding="2,2,2,1">
<Image Source="{StaticResource TB_NewIcon}" Height="16" Width="16" SnapsToDevicePixels="True" RenderOptions.BitmapScalingMode="NearestNeighbor"/>
</Button>
For the Button Tag, the Padding attribute is needed to ensure that the image isn't truncated at a height of 15 pixels, and that the button isn't resized to fit the image. Alternatively, we could specify Padding="1", but then we must manually set Height="21" and Width="22" to ensure the button isn't resized to fit the image
On the Image Tab, the Height and Width are needed to ensure that the image isn't stretched. SnapsToDevicePixels and RenderOptions.BitMapScalingMode are both needed to ensure that there is no blurring. I can't promise that this will work nicely for all resolutions.
Note:
For the NewDocumentHS.png icon, the one that causes the most issues,as it takes up the full 16 pixels of height, you may want to adjust the padding to "1,1,3,2", so that the bottom aligns more properly with other icons.
You may want to consider trying a new property available now in WPF4.
Leave the RenderOptions.BitmapScalingMode to HighQuality or just don't declare it.
On your root element (i.e. your main window) add this property: UseLayoutRounding="True".
A property previously only available in Silverlight has now fixed all Bitmap sizing woes. :)
Please Note - a few of the effects layout rounding
can have on exact layout:
width and or height of elements may grow or shrink by at most 1 pixel
placement of an object can move by at most 1 pixel
centered elements can be vertically or horizontally off center by at most
1 pixel
More info found here: http://blogs.msdn.com/text/archive/2009/08/27/layout-rounding.aspx