I'm implementing a ListBox whose ItemsPanel is a WrapPanel as per this answer, but there's a twist: my ItemsSource is a grouped CollectionView. With a GroupStyle applied to my ListBox, the wrapping shown in that question doesn't work: the groups are always displayed vertically.
Snooping on my app, here's why:
As you can see, the WrapPanel, defined as my ListBox's ItemsPanelTemplate, appears in the ItemsPresenter within each GroupItem; an implicit, vertically-oriented StackPanel (top item in the pink box) is created to contain the GroupItems themselves.
Is there a way to override this behavior, so the GroupItems are placed in a WrapPanel? Would I have to re-template the entire ListBox?
Update: To illustrate what I'm actually doing with my ListBox and the CollectionView grouping, let me post a little XAML:
<Grid>
<ListBox ItemsSource="{Binding}"
ScrollViewer.VerticalScrollBarVisibility="Disabled"
SelectionMode="Multiple"
ItemContainerStyle="{StaticResource itemStyle}">
<ListBox.GroupStyle>
<GroupStyle>
<GroupStyle.HeaderTemplate>
<DataTemplate>
<TextBlock Text="{Binding Name}" FontWeight="Bold"/>
</DataTemplate>
</GroupStyle.HeaderTemplate>
</GroupStyle>
</ListBox.GroupStyle>
<ListBox.ItemTemplate>
<DataTemplate DataType="{x:Type WpfApplication1:Item}">
<StackPanel Orientation="Vertical">
<TextBlock Text="{Binding Name}" FontSize="10"/>
<TextBlock Text="{Binding Amount, StringFormat={}{0:C}}" FontSize="10"/>
</StackPanel>
</DataTemplate>
</ListBox.ItemTemplate>
<ListBox.ItemsPanel>
<ItemsPanelTemplate>
<WrapPanel Orientation="Vertical"/>
</ItemsPanelTemplate>
</ListBox.ItemsPanel>
</ListBox>
</Grid>
The GroupStyle is at the heart of it: if you remove that, the GroupItems don't get rendered, and the WrapPanel (which you can see appearing beneath the GroupItem in the screenshot above) appears in place of (StackPanel) 98 in the screenshot.
This behavior only seems to occur if you have defined a HeaderTemplate in the GroupStyle.
It can be corrected by setting the GroupStyle.Panel property to contain a WrapPanel:
<ListBox.GroupStyle>
<GroupStyle>
<GroupStyle.HeaderTemplate>
<DataTemplate>
<TextBlock Text="{Binding Name}" FontWeight="Bold"/>
</DataTemplate>
</GroupStyle.HeaderTemplate>
<GroupStyle.Panel>
<ItemsPanelTemplate>
<WrapPanel></WrapPanel>
</ItemsPanelTemplate>
</GroupStyle.Panel>
</GroupStyle>
</ListBox.GroupStyle>
It will look something like this:
You should be able to replace the group style from the items control (ListBox):
<ListBox.GroupStyle>
<Style />
<ListBox.GroupStyle/>
Or, you should also be able to create a DataTemplate based on the group item object:
<DataTemplate DataType="{x:Type GroupItem}">
<Panel />
</DataTemplate>
Related
I just want to display Items in ListView like windows explorer (Large icons). For the same I used the below code.
<ListView Name="lstView" ItemsSource="{Binding MovieList}" >
<ListView.ItemsPanel>
<ItemsPanelTemplate>
<!-- <VirtualizingStackPanel/> --> <!-- Working Fine -->
<StackPanel/> <!-- Items are not displayed -->
<!-- It must be wrap panel -->
<!-- OK, lets see with simple -->
</ItemsPanelTemplate>
</ListView.ItemsPanel>
<ListView.ItemTemplate>
<DataTemplate>
<StackPanel Orientation="Horizontal">
<Label Content="{Binding Path}" />
</StackPanel>
</DataTemplate>
</ListView.ItemTemplate>
</ListView>
In the above code, If I use VirtualizingStackPanel then the items are displayed fine, but one by one which I don't want. If I use StackPanel, the items are not dispalyed in screen, even the items are not added in StackPanel. I checked with Snoop tool.
I should use WrapPanel instread of StackPanel to list items, but lets see the simple StackPanel.
Why the items are not displayed in StackPanel?
Basically I want list the items like WindowExplorer large icon view.
I am using .NET 4.0
I tried same thing in my code and it's working fine. Virtualization works as long as size of the ItemsControl's viewport is restricted.
just try replacing the code given below:
<ListView ItemsSource="{Binding Movies}" Width="400" HorizontalAlignment="Left" >
<ListView.ItemsPanel>
<ItemsPanelTemplate>
<WrapPanel VirtualizingPanel.IsVirtualizing="True" />
</ItemsPanelTemplate>
</ListView.ItemsPanel>
<ListView.ItemTemplate>
<DataTemplate>
<StackPanel Orientation="Vertical">
<StackPanel Orientation="Horizontal">
<TextBlock Text="{Binding Year}" FontSize="12" Margin="10,0,0,0"/>
<TextBlock Text="{Binding Name}" FontSize="12" Margin="10,0,0,0"/>
</StackPanel>
<StackPanel Orientation="Horizontal">
<TextBlock Text="{Binding Category}" FontSize="12" Margin="10,0,0,0"/>
<TextBlock Text="{Binding Director}" FontSize="12" Margin="10,0,0,0"/>
</StackPanel>
</StackPanel>
</DataTemplate>
</ListView.ItemTemplate>
</ListView>
I have WrapPanel where I want the control inside of it to go horizontally and centered, but when I have a listbox or a ItemsControl those elements just go downwards.
<toolkit:WrapPanel>
<ItemsControl x:Name="AnswerListBox" ItemsSource="{Binding Answers}" ScrollViewer.VerticalScrollBarVisibility="Disabled" >
<ItemsControl.ItemTemplate>
<DataTemplate>
<!-- those don't wrap horizontally and go downwards -->
<local:spriteToggleButton Text="{Binding text}" Selected="{Binding selected}" Sprites="{Binding Path=DataContext.UISprites, ElementName=questionField}" IsChecked="{Binding selected, Mode=TwoWay}" GroupName="{Binding Path=DataContext.QuestionTitle, ElementName=questionField}" ClickMode="Press" />
</DataTemplate>
</ItemsControl.ItemTemplate>
</ItemsControl>
</toolkit:WrapPanel>
I came across some similar issues and found out about ItemsPanel, so I tried that but it wrap but only to Content and didn't display the rest of the control inside of it.
<ItemsControl.ItemsPanel>
<ItemsPanelTemplate>
<toolkit:WrapPanel />
</ItemsPanelTemplate>
</ItemsControl.ItemsPanel>
I take it that ItemsPanel is telling the ItemsControl which control to wrap it with but then it seems to ignore the rest of my datatemplate.
Joseph,
Slightly shooting in the dark here; but this is how I have used the WrapPanel (not through the ItemControl).
<ListBox>
<ListBox.ItemsPanel>
<ItemsPanelTemplate>
<toolkit:WrapPanel Width="700" />
</ItemsPanelTemplate>
</ListBox.ItemsPanel>
<ListBox.ItemTemplate>
<DataTemplate>
....
</DataTemplate>
</ListBox.ItemTemplate>
</ListBox>
Essentially the Listbox's ItemsPanel tells it to use the WrapPanel and then you could have anything you need in the DataTemplate. Note that the width is important as it tells the WrapPanel where to start wrapping.
Does this help?
I have an ItemsControl using a StackPanel to display a list of items.
I would like a label to appear for each row, but for the content to the left of the label to be defined by a DataTemplateSelector. I do not want to redefine the label for each DataTemplate generated by the TemplateSelector.
Is this possible?
<ItemsControl ItemsSource="{Binding Path=Values}" >
<ItemsControl.Resources>
<v:MyTemplateSelector x:Key="myTemplateSelector"></v:MyTemplateSelector>
</ItemsControl.Resources>
<ItemsControl.ItemsPanel>
<ItemsPanelTemplate>
<StackPanel></StackPanel>
</ItemsPanelTemplate>
</ItemsControl.ItemsPanel>
<ItemsControl.ItemTemplate>
<DataTemplate>
<WrapPanel>
<Label>Test: </Label>
<!--What goes here should be defined by myTemplateSelector-->
</WrapPanel>
</DataTemplate>
</ItemsControl.ItemTemplate>
</ItemsControl>
I figured it out. The solution was to use a ContentPresenter element with a ContentTemplateSelector attribute:
<DataTemplate>
<WrapPanel>
<Label>Test: </Label>
<ContentPresenter
ContentTemplateSelector="{StaticResource ResourceKey=myTemplateSelector}">
</ContentPresenter>
</WrapPanel>
</DataTemplate>
I'm trying to get an ItemsPanelTemplate working for a ListBox. The ListBox is used in a DataTemplate, and none of my implicit ListBox styles override the default visual style. For some reason, the ItemsPanelTemplate I'm specifiying for the control (a WrapPanel) is being ignored and a StackPanel is used instead.
This is the entire template, I can only assume there's something I'm missing which is causing this.
<DataTemplate x:Key="GroupLargeIconsTemplate" DataType="{x:Type Core:IGroup}">
<ListBox ItemsSource="{Binding Children}" OverridesDefaultStyle="True">
<ListBox.ItemsPanel>
<ItemsPanelTemplate>
<WrapPanel HorizontalAlignment="Left" VerticalAlignment="Top" IsItemsHost="True" ScrollViewer.HorizontalScrollBarVisibility="Disabled" ScrollViewer.VerticalScrollBarVisibility="Auto"
Width="{Binding (FrameworkElement.ActualWidth), RelativeSource={RelativeSource AncestorType=ScrollContentPresenter}}" />
</ItemsPanelTemplate>
</ListBox.ItemsPanel>
<ListBox.ItemTemplate>
<DataTemplate>
<DataTemplate.Resources>
<conv:IconConverter x:Key="IconConverter"/>
</DataTemplate.Resources>
<StackPanel Margin="2" Width="100" Height="140">
<Image Source="{Binding Icon,Converter={StaticResource IconConverter},ConverterParameter=96}"/>
<TextBlock Text="{Binding Name}" TextWrapping="Wrap" TextTrimming="CharacterEllipsis" />
</StackPanel>
</DataTemplate>
</ListBox.ItemTemplate>
</ListBox>
</DataTemplate>
My guess is that the width property in the WrapPanel is making it behave as a Stackpanel.
Strange, the control template is not supposed to override the explicitly specified values, rather the opposite scenario comes to my mind...
That is, unless the control template provides a panel with "IsItemsHost" set to true. Then the ItemsPanel is ignored. Which, probably, is your case.
In WPF Listbox, I'm confused with these 2 notions:
ItemTemplate and ItemsPanelTemplate
Can someone explain me more?
Thanks
John
Let me try to explain this by example:
<ListBox ItemsSource="{Binding}">
<ListBox.ItemTemplate>
<DataTemplate>
<Border Background="SteelBlue" Padding="5" BorderBrush="Black"
BorderThickness="1" Margin="0,2">
<TextBlock Text="{Binding}"/>
</Border>
</DataTemplate>
</ListBox.ItemTemplate>
<ListBox.ItemsPanel>
<ItemsPanelTemplate>
<StackPanel Background="DarkKhaki"/>
</ItemsPanelTemplate>
</ListBox.ItemsPanel>
</ListBox>
And the result:
The ItemTemplate determines the layout of each item in the list. On the other hand the ItemsPanel is the panel that will contain the individual items. Given the above definition the visual tree will be something similar to this:
<StackPanel>
<Border>
<TextBlock Text="Alpha"/>
</Border>
<Border>
<TextBlock Text="Beta"/>
</Border>
....
</StackPanel>
ItemTemplate is used to specify a DataTemplate used to render the item in your ListBox.
ItemPanelTemplate is used to specify the panel used to arrange the children of your ListBox.
For example, if your ListBox is bound to an ObservableCollection you must specify a DataTemplate to tell it how to render each Person object.
<ListBox ItemsSource={Binding Persons}>
<ListBox.ItemTemplate>
<DataTemplate>
<StackPanel>
<TextBlock Text={Binding FirstName}/>
<TextBlock Text={Binding LastName}/>
<TextBlock Text={Binding Age}/>
</StackPanel>
</DataTemplate>
</ListBox.ItemTemplate>
</ListBox>
That will arrange each item vertically because ListBox used a StackPanel by default. If you want to change this behaviour, used the ItemPanelTemplate property:
<ListBox>
<ListBox.ItemsPanel>
<ItemsPanelTemplate>
<StackPanel Orientation="Horizontal"/>
</ItemsPanelTemplate>
</ListBox.ItemsPanel>
</ListBox>
You can even change the StackPanel to any other panel (WrapPanel for example).