I'm trying to implement a certain layout.
I have two elements that I want to stack vertically (I need them to follow each other closely). I am currently trying to achieve it using a Stackpanel.
The problem is that I want the first element to have a limited width and the other to use all the width available in the StackPanel. Ideally, I would like that the first element have a width equals to the width of four columns from the grid that contains the StackPanel, here is my code.
<Grid>
<!-- Colums and Rows definition go here -->
<StackPanel Grid.Column="0" Grid.ColumnSpan="4" Grid.Row="3" Grid.RowSpan="8">
//The first element
<Viewbox Name="viewbox_choix" Margin="160,0,0,0" HorizontalAlignment="Left" VerticalAlignment="Top" Grid.Column="0" Grid.ColumnSpan="4" Grid.Row="3" Grid.RowSpan="4">
//The second element
<StackPanel Grid.Column="0" Grid.ColumnSpan="5">
<Border></Border>
etc...
</StackPanel>
</StackPanel>
</Grid>
The grid attributes are referring to the parent grid of the stackpanel. But the Grid.Column and Grid.ColumnSpans seem to have no effect when I try to use them inside the StackPanel.
The problem of that code is that the first element also uses all the width of the StackPanel but that isn't what I want...
Can anybody help me ? I precise that I'm still learning WPF and I don't really know how bindings work...
In WPF, a StackPanel does not work like a Grid. There is no maximum width... it will happily let content disappear out of its right side. If you want automatic resizing, just replace the StackPanels with `Grid
UPDATE >>>
In the Grid class, there is an attached property called IsSharedSizeScope. Add this to the parent Grid and set it to true. Then in your RowDefinitions, you can add SharedSizeGroup properties to the columns that you require.
These examples may help you:
Grid's SharedSizeGroup and * sizing (SO post)
Grid.IsSharedSizeScope Attached Property (MSDN)
You may need to experiment a bit, but you should be able to get the desired effect using these properties.
Related
I am trying to set up an element within a WPF application, but cannot get the TextTrimming on the TextBlocks to work properly. This is within a ScrollViewer. I am currently using a DockPanel as the inner container.
I have searched quite a bit, but found no questions addressing this issue.
The XAML for the container:
<Grid>
<ScrollViewer>
<DockPanel Name="listedCharacters" LastChildFill="False"></DockPanel>
</ScrollViewer>
</Grid>
The XAML for the child elements (added by code):
<UserControl …>
<Grid DockPanel.Dock="Top" HorizontalAlignment="Stretch">
<TextBlock Text="{Binding FullName}" TextTrimming="CharacterEllipsis" />
</Grid>
</UserControl>
The first problem is that whether I use the DockPanel or a StackPanel, as the inner container, the child element's width appears to be dictated by its content (the TextBlocks) rather than constrained by the parent ScrollViewer.
The effect I want is for the ellipsis to truncate each TextBlock's content when the Window's grid column (not shown in code) is narrower than the bound text. Basically, a list that scrolls vertically when needed, and trims horizontally (which I thought would have been sufficiently common that the answer would be out there; alas, no).
I believe I need to use my own UserControl for this, as there is a lot more going on than shown her; right-click menus on the item in the list, etc.
The secondary issue, iff the optimal panel to use is the DockPanel, how to apply the DockPanel.Dock="Top" through code (C#) when the elements are dynamically added? Again, I cannot find anything that appears to explain this. (I know it is probably in the wrong place in the sample code above.)
I'm trying to figure out how to make my ContentControl to correctly scroll Horizontally (Vertically its fine at the moment). By correctly i mean i would like to see the content to stretch (expand infinitely) while having minimum sizes to which a scrollbar would appear in order for the content not to overflow behind the ContentControl's area, so here's a quick introduction:
The main window is structured in this way:
Grid (2 columns of .3* and .7*)
Border
Grid (7 rows, one set to * where ContentControl is)
ScrollViewer with StackPanel (purely for test) wrapping a ContentControl that has Auto Width
ContentControl's Template:
Grid (Width set to UserControl's ActualWidth, 6 rows with one set to Auto where ItemsControl go
ItemsControl that describes an ItemTemplate of a type DataTemplate which contains a Grid inside of which i have a DataGrid
The actual problem is that the ContentControl grows as you resize the window, but does not shrink with window resize.
Main View XAML (truncated for clarity):
<ScrollViewer Grid.Row="5" VerticalScrollBarVisibility="Auto" HorizontalScrollBarVisibility="Auto">
<ContentControl Grid.Row="5" Background="Transparent" Focusable="False" Margin="0,5,0,0"
Content="{Binding CurrentSection}" ContentTemplateSelector="{StaticResource templateSelector}/>
</ScrollViewer>
Tempate XAML (truncated for clarity):
<Grid>
...
<ItemsControl Grid.Row="4" ItemsSource="{Binding Data.QualifyingDistributionsDividends}" x:Name="QualifyingItemsControl">
<ItemsControl.ItemTemplate>
<DataTemplate>
<Grid x:Name="DTLayoutGrid">
...
<Grid Grid.Row="1" x:Name="DataLayout" Width="{Binding ElementName=DTLayoutGrid, Path=ActualWidth}" HorizontalAlignment="Stretch">
...
<DataGrid Grid.Row="1" Grid.Column="0" Grid.ColumnSpan="8" HorizontalScrollBarVisibility="Disabled"
ItemsSource="{Binding Payments}" Style="{StaticResource DataGridStyle}" CellStyle="{StaticResource DataGridNormalCellStyle}">
</DataGrid>
</Grid>
</Grid>
</DataTemplate>
</ItemsControl.ItemTemplate>
</ItemsControl>
</Grid>
So what happens? Datagrid assumes width of the entire DataTemplate (well its underlying controls that are set to be DataTemplates size, then * column assumes all empty space. When you try to resize the entire window that holds this code it will grow correctly, expanding the * column but it seems shrinking is not "registered" and it keeps the size you expanded it to, applies a scrollbar over that and forgets about it.
What i've tried so far was to set widths for ItemsControl, its underlying parents like Grid etc, also setting size to ContentControl, StackPanel, ScrollViewer and parent Grid of that.
I've also tried using scrollviewers directly on the Datagrid which produces an epileptic "1 million resizes a second" scenario. I've also played around with HorizontalAlignments
Under certain situations i DID managed to get the horizontal scrollbar to appear correctly but unfortunately that makes my DataGrid's * column to assume Auto Width rather then Star so DataGrid starts having an empty area to the right (unacceptable unfortunately...)
I understand that in order for horizontal scrollbar to work the parent or child of the scrollviewer needs Width set, i guess i can't work out where exactly do i need to restrict it. DataGrids NEED to infinitely expand with the main window while having first column fill all the available space.
Do let me now if you need more information on this and I will gladly answer.
It seems to me that this is just another case of the dreaded StackPanel layout problem. This problem comes up again and again and I confess that I had the very same problem when I started learning WPF. The StackPanel does not take the available size of its parent into consideration whereas other Panels such as a DockPanel or a Grid (yes, that's actually a Panel too) do.
It's explained in the How to: Choose Between StackPanel and DockPanel page on MSDN:
Although you can use either DockPanel or StackPanel to stack child elements, the two controls do not always produce the same results. For example, the order that you place child elements can affect the size of child elements in a DockPanel but not in a StackPanel. This different behavior occurs because StackPanel measures in the direction of stacking at Double.PositiveInfinity; however, DockPanel measures only the available size.
The StackPanel should only really be used to align a number of items, such as Buttons or other controls in a straight line where available space is not a concern. So anyway, the solution should be simple... just remove the StackPanel from the ScrollViewer. It doesn't appear to serve any purpose there anyway.
UPDATE >>>
After looking again, it seems as though you're saying that the problem is inside the DataTemplate, right? You might be able to fix that by setting the ItemsControl.HorizontalContentAlignment property to Stretch. That would ensure that each item remains within the boundary of the ItemsControl.
I'd also remove your Binding on the Grid.Width as you don't need it... a child Grid will take up the full space of a parent Grid by default. If these ideas don't work, just simplify your problem. Seriously, if you follow the advise in the linked page from the Help Center that I gave you in the comments, then you'll either fix the problem, or be able to come back here and provide a complete, but concise example that we could test.
I've found the behavior I was looking for by using a UniformGrid as the ItemsPanel, with its rows bound to the count of the ItemsSource model:
<ScrollViewer>
<ItemsControl ItemsSource="{Binding MyCollection}">
<ItemsControl.ItemsPanel>
<ItemsPanelTemplate>
<UniformGrid Rows="{Binding MyCollection.Count}" />
</ItemsPanelTemplate>
</ItemsControl.ItemsPanel>
<ItemsControl.ItemTemplate>
<DataTemplate>
...
</DataTemplate>
</ItemsControl.ItemTemplate>
</ItemsControl>
</ScrollViewer>
As #Sheridan pointed out above, it seems the StackPanel is causing trouble. Also, credit to https://stackoverflow.com/a/23375262/385273 for pointing out the UniformGrid option.
How can canvas in wpf be autosized? I have a canvas in scrollviewer and I will add several buttons and lines in this canvas in code behind. since I don't know the position of the buttons, I have to hard code a very large number for the width and height of the canvas or if I add too many buttons, it can only show part of them.
I try to set the Width and Height to Auto but it doesn't work.
<Grid>
<ScrollViewer HorizontalScrollBarVisibility="Visible" VerticalScrollBarVisibility="Visible">
<Canvas Width="Auto" Height="Auto" Name="cv1"></Canvas>
</ScrollViewer>
</Grid>
The Canvas element is the only element that can not be automatically resized, because has no inherent layout characteristics. If you want the Control to be resized as child elements come in, you could use something deriving from Grid.
Try a UniformGrid instead of your Canvas ans fill it with the elements you want. It allows you to just add elements without any layout constraints that are handled by the UniformGrid. otherwise if you use a simple Grid, you will have to define a Position for your element by setting the Margin property of each child element.
Hope this helps.
In a scenario like this:
<StackPanel x:Name="StackPanel1" VerticalAlignment="Stretch" HorizontalAlignment="Stretch" Orientation="Horizontal">
<Element1/>
<Element2>
</StackPanel>
It possible to stretch last element (Element2) in control list to fit all possible space (like width="*")?
I am forced to use a grid?
The StackPanel content area collapses to fit the children. Stretch in the direction that grows on a StackPanel is only useful for painting the background. It does not affect the children.
Use a grid or a custom container.
I have a databound and itemtemplated ListBox:
<ListBox x:Name="lbLista"
ScrollViewer.VerticalScrollBarVisibility="Visible">
<ListBox.ItemTemplate>
<DataTemplate>
<StackPanel Orientation="Horizontal">
<CheckBox IsChecked="{Binding Deleteable, Mode=TwoWay}" />
<Label Content="{Binding Name}" />
</StackPanel>
</DataTemplate>
</ListBox.ItemTemplate>
</ListBox>
The ites show fine and they come from an ObservableCollection.
The problem is the scrollbar which appears but is not usable - it does not have a handle to grab. I've tried setting some ScrollView attached properties on ListBox, but they do not affect the situation.
I pasted your code into test project, added about 20 items and I get usable scroll bars, no problem, and they work as expected. When I only add a couple items (such that scrolling is unnecessary) I get no usable scrollbar. Could this be the case? that you are not adding enough items?
If you remove the ScrollViewer.VerticalScrollBarVisibility="Visible" then the scroll bars only appear when you have need of them.
ListBox will try to expand in height that is available.. When you set the Height property of ListBox you get a scrollviewer that actually works...
If you wish your ListBox to accodate the height available, you might want to try to regulate the Height from your parent controls.. In a Grid for example, setting the Height to Auto in your RowDefinition might do the trick...
HTH
I have never had any luck with any scrollable content placed inside a stackpanel (anything derived from ScrollableContainer. The stackpanel has an odd layout mechanism that confuses child controls when the measure operation is completed and I found the vertical size ends up infinite, therefore not constrained - so it goes beyond the boundaries of the container and ends up clipped. The scrollbar doesn't show because the control thinks it has all the space in the world when it doesn't.
You should always place scrollable content inside a container that can resolve to a known height during its layout operation at runtime so that the scrollbars size appropriately. The parent container up in the visual tree must be able to resolve to an actual height, and this happens in the grid if you set the height of the RowDefinition o to auto or fixed.
This also happens in Silverlight.
-em-
Thnaks for answer. I tried it myself too to an Empty Project and - lo behold allmighty creator of heaven and seven seas - it worked. I originally had ListBox inside which was inside of root . For some reason ListBox doesn't like being inside of StackPanel, at all! =)
-pom-