I am new to xaml and wpf.
I am trying to insert some user controls into a container from the code-behind.
I have read this blog entry on MSDN.
I tried all the methods used there and some others but the scroll bar is never enabled.
My current code that I stuck with is this:
<DockPanel>
<ScrollViewer HorizontalAlignment="Left" Margin="252,12,0,0">
<ItemsControl Name="captchaControls" Width="339" Height="286">
</ItemsControl>
</ScrollViewer>
</DockPanel>
Does anyone know why?
EDIT:
Made it work like this:
<DockPanel>
<ScrollViewer HorizontalAlignment="Left" Margin="252,12,0,0" Width="339" Height="286">
<ItemsControl Name="captchaControls">
</ItemsControl>
</ScrollViewer>
</DockPanel>
Remove Width="339" Height="286" from XAML. It causes ItemsControl to have constant size no matter what is inside it.
BTW. You should probably use x:Name instead of Name, google for articles explaining why.
How can I create the effect similar to Windows Phone's MessageBox, where the message gets displayed on a new layer with transparent background, so that the windows becomes modal? My layout is created out of Grid, so I do not know how to add any content over it. Please help.
It's easy to overlay one set of content with another in WPF. Try changing the visibility of the border below, for a simple message box effect. You would of course bind Visibility to your view model, or set it in code behind.
<Grid>
<Grid>
<!-- All your layout here -->
</Grid>
<Border Height="100" Width="100" Background="Azure" Visibility="Hidden">
<TextBlock Text="Hi there" HorizontalAlignment="Center" VerticalAlignment="Center"/>
</Border>
</Grid>
I'm using a Popup control, and for some reason its vertical alignment doesn't work as I expect. This is the XAML I have:
<Grid Width="100" Height="30" >
<TextBox Text="Hello" />
<Popup IsOpen="True" VerticalAlignment="Bottom" HorizontalAlignment="Stretch" >
<Button Content="Hello" />
</Popup>
</Grid>
I expected that the Popup's Width would be 100px, the same as it's parent Grid.
However, the Button inside the popup behaves as if its HorizontalAlignment is Left, i.e., the Button's width is just enough to allow the word "Hello" inside of it, and I can't figure out why, or how to make it have the same width as the containing Grid.
Thanks!
Unfortunately, a Popup is not part of the same visual tree as the rest of the elements in the XAML in which it is defined. It is literally a new window, albeit a very simple and typically small window.
Put another way, the Popup doesn't really participate in the layout of the main window. So changing things like HorizontalAlignment has no effect because that property controls how layout positions and sizes this element relative to its containing element.
This "orphaned element" issue causes no end of problems when dealing with a Popup. Nevertheless, there are tools and techniques to address all the problems that being a separate window introduces.
The first suggestion I can give is to understand the placement properties, PlacementTarget and Placement. You can use these properties for positioning the Popup. You can also use the ElementName syntax of databinding to take care of sizing.
Here is an example of using these techniques in your situation:
<Grid Name="grid" Width="100" Height="30" >
<TextBox Text="Hello" />
<Popup IsOpen="True"
Placement="Bottom"
PlacementTarget="{Binding ElementName=grid}"
Width="{Binding ActualWidth, ElementName=grid}">
<Button Content="Hello" />
</Popup>
</Grid>
I have an ItemsControl in my user control with a scroll viewer around it for when it gets too big (Too big being content is larger than the viewable area of the UserControl). The problem is that the grid that it is all in just keeps expanding so that the scroll viewer never kicks in (unless I specify an exact height for the grid). See code below and thanks in advance.
<UserControl x:Class="BusinessObjectCreationWizard.View.TableSelectionPageView"
xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml">
<GroupBox FontWeight="Bold" Height="300px"
Header="Tables"
Padding="2">
<ScrollViewer>
<ItemsControl FontWeight="Normal"
ItemsSource="{Binding Path=AvailableTables}">
<ItemsControl.ItemTemplate>
<DataTemplate>
<CheckBox Content="{Binding Path=DisplayName}"
IsChecked="{Binding Path=IsSelected}"
Margin="2,3.5" />
</DataTemplate>
</ItemsControl.ItemTemplate>
</ItemsControl>
</ScrollViewer>
</GroupBox>
</UserControl>
This user control is loaded here
<Border Background="White" Grid.Column="1" Grid.Row="0">
<HeaderedContentControl Content="{Binding Path=CurrentPage}"
Header="{Binding Path=CurrentPage.DisplayName}" />
</Border>
I would like to not specify the height.
If you remove the Height from your GroupBox (which, as far as I understand, is what you want to do), then it will fill its container, unless there's a panel upstream that imposes its own sizing rules.
I used this simplified version of your XAML. I removed the template and the binding, and hard-coded some items, to make this stand alone; those changes won't affect the way layout is done.
<Window xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation">
<GroupBox FontWeight="Bold" Header="Tables" Padding="2">
<ScrollViewer>
<ItemsControl FontWeight="Normal">
<TextBlock>Foo</TextBlock>
<TextBlock>Bar</TextBlock>
<TextBlock>Baz</TextBlock>
</ItemsControl>
</ScrollViewer>
</GroupBox>
</Window>
Run it, and you'll see that the content does indeed size to fit the window, and the scrollbar only enables when the window gets too small to see all three items. I believe this is what you want.
So the problem is most likely one of the parent panels, one you're not showing in your sample XAML. The problem you describe could occur if your GroupBox appears inside a StackPanel:
<Window xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation">
<StackPanel>
<GroupBox FontWeight="Bold" Header="Tables" Padding="2">
<ScrollViewer>
<ItemsControl FontWeight="Normal">
<TextBlock>Foo</TextBlock>
<TextBlock>Bar</TextBlock>
<TextBlock>Baz</TextBlock>
</ItemsControl>
</ScrollViewer>
</GroupBox>
</StackPanel>
</Window>
Now the GroupBox appears at the top of the Window, sized to exactly fit its contents. If you shrink the Window enough, the GroupBox will be cut off -- because it's sized to fit its content, not its container. This sounds like the problem you're describing.
The reason is that StackPanel asks its children what their ideal height is (based on their content), and uses that height. Without StackPanel (or something similar), the default is to respect the control's VerticalAlignment, and if that's set to the default value of Stretch, then the control is stretched to fill its parent. This means it won't be taller than its parent, which sounds like what you want.
Solution: remove the StackPanel (or whatever else is causing you problems) and use something else. Depending on what you're trying to accomplish, you might have better luck with a DockPanel or a Grid. Hard to tell without knowing more about your layout.
Edit: Okay, it looks like the problem is indeed the HeaderedContentControl parent -- but not directly. HeaderedContentControl isn't a panel, so it doesn't do any layout of its own (and its descendant, GroupBox, doesn't have this same problem). The problem is its default template -- which includes a StackPanel. The good news is, you're free to use a different template, let's say one with a DockPanel instead:
<Window xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml">
<HeaderedContentControl>
<HeaderedContentControl.Style>
<Style TargetType="{x:Type HeaderedContentControl}">
<Setter Property="Template">
<Setter.Value>
<ControlTemplate TargetType="{x:Type HeaderedContentControl}">
<DockPanel>
<ContentPresenter ContentSource="Header" DockPanel.Dock="Top"/>
<ContentPresenter/>
</DockPanel>
</ControlTemplate>
</Setter.Value>
</Setter>
</Style>
</HeaderedContentControl.Style>
<GroupBox FontWeight="Bold" Header="Tables" Padding="2">
<ScrollViewer>
<ItemsControl FontWeight="Normal">
<TextBlock>Foo</TextBlock>
<TextBlock>Bar</TextBlock>
<TextBlock>Baz</TextBlock>
</ItemsControl>
</ScrollViewer>
</GroupBox>
</HeaderedContentControl>
</Window>
If you leave off the <HeaderedContentControl.Style> part, this reproduces your problem; but with the style in place, it allows the GroupBox to fill its container, so the ScrollViewer will get a scrollbar when you want it to.
If the previous answer doesn't fix the problem, you could also try binding the Width, Height of your grid to the ActualWidth, ActualHeight of your parent UserControl. Something like:
<UserControl
xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
x:Class="WpfApplication.UserControl1"
x:Name="UserControl">
<Grid Height="{Binding ElementName=UserControl, Path=ActualHeight}"
Width="{Binding ElementName=UserControl, Path=ActualWidth}" />
In this case you aren't setting an explicit width and height but you are limiting the Grids width/height to the constraints of the UserControl it sits in.
I had the same issue, after reading this response I replaced all StackPanels with Grids in UserControl. It resolved the Scrollbar issue.
Try removing the grid entirely and setting the HorizontalAlignment and VerticalAlignment directly on the GroupBox. If a layoutpanel has only one child, it's often redundant... this migth be true in your case.
If that doesn't work... what's the parent of your grid control?
Why not just use a listbox instead of an itemscontrol, that has a built in scrollviewer.
They are different. If you do not want to have the items selectable, then don't use a ListBox. It is going to be heavier, and will also have the deselect a selection everytime the user clicks on an entry. Just put the ItemsControl in a ScrollViewer
I had the same problema with ListBox, it wasn't expanding and the scroll viewer didn't appear. I solved it as follows:
<UserControl x:Class="TesteView"
xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml">
<Grid MaxHeight="710">
....
....
<StackPanel>
<ListBox MaxHeight="515"
ScrollViewer.HorizontalScrollBarVisibility="Hidden"
ScrollViewer.VerticalScrollBarVisibility="Auto"
ItemsSource="{Binding Path=Teste,Mode=TwoWay}">
....
....
</ListBox>
</StackPanel>
</Grid>
</UserControl>
I've spent a few minutes searching on Google and have not found anything related to this issue I'm having:
Today I upgraded to the Silverlight 3 SDK and converted a project that I'm working on. I then noticed a bug in my program with a Listbox that has a Checkbox as its DataTemplate.
When one or more items is checked, and I scroll up and down, it seems that a few of the Checkboxes at the extremes get checked off and on randomly. This does not trigger the Checked/Unchecked event, however.
Has anyone seen this behavior? I'm not doing anything out of the ordinary, simply scrolling up and down once at least one checkbox has been checked, and a couple of others that I have not touched seem to get checked on and off repeatedly. This was definitely not happening with the Silverlight 2 SDK.
Here's the XAML definition for my Listbox:
<ListBox x:Name="cBoxSalesmen" Width="135" Height="200"
HorizontalAlignment="Left" VerticalAlignment="Top">
<ListBox.Template>
<ControlTemplate>
<Border Style="{StaticResource BorderStyleThin}">
<StackPanel Orientation="Vertical">
<TextBlock Text="Salesmen" />
<ScrollViewer Height="176" VerticalScrollBarVisibility="Visible" >
<ItemsPresenter />
</ScrollViewer>
</StackPanel>
</Border>
</ControlTemplate>
</ListBox.Template>
<ListBox.ItemTemplate>
<DataTemplate>
<CheckBox Margin="0" Content="{Binding}" FontSize="10" HorizontalAlignment="Left"
Checked="SalesmenCheckbox_Checked" Unchecked="SalesmenCheckbox_Unchecked"/>
</DataTemplate>
</ListBox.ItemTemplate>
</ListBox>
The default ItemsPanel of the ListBox is the VirtualizingStackPanel. You can change it to use the StackPanel, this way you problem is solved.
Use this code:
<ListBox.ItemsPanel>
<ItemsPanelTemplate>
<StackPanel />
</ItemsPanelTemplate>
<ListBox.ItemsPanel>
I suspect your problem is a result of ListBox (in SL3) now using an ItemCollectionGenerator. The concept behind this is that not all the objects found in the source data collection need to have had their corresponding instance of the DataTemplate created and added to the Visual Tree. As you scroll toward the bottom items that may soon be needed are created. Additionally items that have already be created but are now scrolled quite same way out of view can be removed. If the user scrolls up they are re-created.
If this is the case then the IsChecked state of any checkbox in this list will be lost at some point for large lists. To solve this you would need include a property in the data type to which you can bind IsChecked. Hence as ListBox re-creates items it correctly assigns the IsChecked value.