We Keep Coding

How to keep canvas a fixed size while stretching its container

I am trying to make a really simple editor for images. Since the control panel is showed right next to the Canvas, I'd like to put a border between them (I am open to suggestions like a GridSplitter though). I have the Canvas nested in a ScrollViewer nested in a Border. When the image loads in the Canvas, if I resize the window I the image resizes with everything else. Since I am editing this image, I'd like to keep it to its original size and, if the Canvas is to big, use the ScrollViewer to handle that. I don't know if it is more recommendable to put the border around the Control Panel instead.
XAML Code:
<Border BorderBrush="Black" BorderThickness="2" Grid.Column="2" Grid.Row="0" Grid.RowSpan="10" Height="Auto" Width="Auto" HorizontalAlignment="Stretch" VerticalAlignment="Stretch">
<ScrollViewer x:Name="canvas_RosetteMap" Height="Auto" Width="Auto" VerticalScrollBarVisibility="Auto" HorizontalScrollBarVisibility="Auto">
<Canvas Grid.Column="2" HorizontalAlignment="Center" Height="Auto" Grid.Row="0" Grid.RowSpan="10" VerticalAlignment="Center" Width="Auto"/>
</ScrollViewer>
</Border>

You should use a Grid instead. Canvas are not good at handling resizing, scrolling or anything like that. Here is a simple example that should work with an Image also:
<Border BorderBrush="Black" BorderThickness="2" HorizontalAlignment="Stretch" VerticalAlignment="Stretch">
<ScrollViewer x:Name="canvas_RosetteMap" VerticalScrollBarVisibility="Auto" HorizontalScrollBarVisibility="Visible">
<Grid Width="Auto">
<TextBox Background="Beige" VerticalAlignment="Top" HorizontalAlignment="Left"/>
</Grid>
</ScrollViewer>
</Border>

WPF ScrollView and TextBlock

What am I doing wrong?
The following code works:
<ScrollViewer x:Name="scrollChatMessages">
<TextBlock x:Name="txtChatMessages" TextWrapping="Wrap"/>
</ScrollViewer>
But once I touch it up with the designer so it looks neater and doesn't take over the entire Grid, the ScrollView doesn't scroll the content of the Scrollblock anymore:
<ScrollViewer x:Name="scrollChatMessages" HorizontalAlignment="Left" Height="181" Margin="95,10,0,0" VerticalAlignment="Top" Width="300">
<TextBlock x:Name="txtChatMessages" HorizontalAlignment="Left" TextWrapping="Wrap" VerticalAlignment="Top" Height="181" Width="300"/>
</ScrollViewer>
Could someone explain this behaviour to me?
Thanks in advance!

Without a good Minimal, Complete, and Verifiable code example it's impossible to say for sure. But you can see that the Designer has added a bunch of new property values for both elements. In particular, the ScrollViewer and TextBlock have been set to have the same exact width and height.
Naturally, with the contained element having exactly the correct dimensions to fit within the ScrollViewer, there's no need to scroll to see all of it. You need to remove the Width and Height property values from the TextBlock.

I solved it by placing it inside of a Grid.
<Grid x:Name="gridChatMessages" HorizontalAlignment="Left" Height="181" Margin="95,10,0,0" VerticalAlignment="Top" Width="300">
<ScrollViewer x:Name="scrollChatMessages">
<TextBlock x:Name="txtChatMessages" TextWrapping="Wrap"/>
</ScrollViewer>
</Grid>

WPF ScrollViewer is not working

I want to add scroll view to my program and I tried ScrollView control but that don't take effect. It's my first time dealing with scrolls please help me :).
My xaml Code:
<DockPanel Grid.Row="1" Background="#FF695887">
<ScrollViewer VerticalScrollBarVisibility="Auto" Height="795">
<Canvas Name="zemelapis" Height="Auto" Width="Auto">
<Image Name="pav_kelias" />
<Image Name="car1" />
</Canvas>
</ScrollViewer>
</DockPanel>
Because these 2 images is not fitting here I need a scroll for them. Maybe I should use ScrollBar?
My program example: https://gyazo.com/a4ba7e4d5004632e2229a87e686c4c09
, as you can see bottom image is not fitting in range of window.

You have specified Auto as Height and Width. This implies that the Canvas will fill the height available to it.
From the documentation:
Auto sizing behavior implies that the element will fill the height
available to it.
In this case the available height is the height of the ScrollViewer.
If you want the Canvas to be bigger, and hence the ScrollViewer to scroll, you should set a height on Canvas that is bigger than the height of ScrollViewer.
So, for example:
<DockPanel Grid.Row="1" Background="#FF695887">
<ScrollViewer VerticalScrollBarVisibility="Auto" Height="795">
<Canvas Name="zemelapis" Height="1000" Width="Auto">
<Image Name="pav_kelias" />
<Image Name="car1" />
</Canvas>
</ScrollViewer>
</DockPanel>

If you want your ScrollViewer to work easily, use a Grid instead of a Canvas:
<DockPanel Background="#FF695887">
<ScrollViewer >
<Grid Name="zemelapis">
<Image Name="pav_kelias" Source="acteurs.png"/>
<Image Name="car1" Source="public.jpg"/>
</Grid>
</ScrollViewer>
</DockPanel>
As explain by Domysee, Canvas gives you total control of the layout. Grid however will automatically adjust its size depending on the content.
See http://www.wpf-tutorial.com/panels/introduction-to-wpf-panels/

WPF stackpanel scrolling issues

i have this in my window and i'll be adding items programmatically to these stacks. problem is i can't scroll through my stuff. i have tried everything that i can find online but i couldn't.
<Border x:Name="Border_Output" Width="463" Height="463" CornerRadius="30"
BorderThickness="0" Background="White">
<Grid>
<StackPanel x:Name="Restaurant_SearchOutputStack"/>
<StackPanel x:Name="Item_SearchOutputStack"/>
<StackPanel x:Name="Order_OutputStack"/>
<StackPanel x:Name="Menu_OutputStack"/>
</Grid>
</Border>

If you have a stackpanel, it is assigned the size of it's items, so the scrollerbar won't appear.
From this article:
As you can see, having a ListBox in a StackPanel causes the
ScrollViewer to disappear, since the StackPanel gives its children the
entire size they need, rendering the collection without the
ScrollViewer.

i found the answer.. it was to have it this way instead.
<ScrollViewer VerticalScrollBarVisibility="Auto">
<Grid>
<StackPanel x:Name="Restaurant_SearchOutputStack"/>
<StackPanel x:Name="Item_SearchOutputStack"/>
<StackPanel x:Name="Order_OutputStack"/>
<StackPanel x:Name="Menu_OutputStack"/>
</Grid>
</ScrollViewer>
and because when i use one stack i collapse the others what i want happens correctly. thanks anyways guys.

WPF Create a slide out panel

I don't know how this works technically but my requirement is as follows. I have a DataGrid and to input data into the DataGrid, I want a panel at the bottom of the DataGrid that slides out on a button click showing input options. Except, as the panel slides out, the DataGrid has to resize vertically as well. Can someone throw some light on how I can implement this?

You should be able to use a StackPanel with 2 children, your grid and your panel. Set the initial height of your panel to 0. Once the button is clicked, set the height to whatever you need it to be (e.g., MyPanel.Height = 20). You might want to wrap the grid in a ScrollViewer in case that is needed.
<StackPanel Orientation="Vertical">
<ScrollViewer Height="Auto" VerticalAlignment="Stretch">
<Grid Height="*" VerticalAlignment="Stretch" />
</ScrollViewer>
<ContentControl x:Name="MyPanel" Height="0" />
</StackPanel>
You might need to experiment with VerticalAlignment and Height="Auto" or Height="0" to get the layout you want.

You can use Expander. Please look at the following code snippet.
<DockPanel>
<Expander DockPanel.Dock="Bottom">
<StackPanel>
<TextBlock Height="25"></TextBlock>
<TextBlock Height="25"></TextBlock>
<TextBlock Height="25"></TextBlock>
</StackPanel>
</Expander>
<Border BorderBrush="LightGreen" BorderThickness="2">
<DataGrid/>
</Border>
</DockPanel >