Today, thanks to a typing mistake, I've managed to produce the following xaml:
<ListView>
first line<Button>second line</Button>the third<system:String>the fourth</system:String>
</ListView>
This will compile and produce a four-line list:
This also works for ListBox, ItemsControl, and ComboBox.
My question: do you know if that is documented anywhere by Microsoft? I've never seen such xaml working before.
All the items you are describing inherit from ItemsControl. The ItemsControl MSDN documentation has an example with multiple types of controls added to a ListBox very similarly to how you have your items added to your ListView.
Relevant XAML from MSDN:
<!--Create a ListBox that contains a string, a Rectangle,
a Panel, and a DateTime object. These items can be accessed
via the Items property.-->
<ListBox xmlns:sys="clr-namespace:System;assembly=mscorlib"
Name="simpleListBox">
<!-- The <ListBox.Items> element is implicitly used.-->
This is a string in a ListBox
<sys:DateTime>2004/3/4 13:6:55</sys:DateTime>
<Rectangle Height="40" Width="40" Fill="Blue"/>
<StackPanel Name="itemToSelect">
<Ellipse Height="40" Fill="Blue"/>
<TextBlock>Text below an Ellipse</TextBlock>
</StackPanel>
<TextBlock>String in a TextBlock</TextBlock>
<!--</ListBox.Items>-->
</ListBox>
Related
I've created a listview. The listview's source is set to a list of "listviewitem"s. The listviewItem's content is set to the specific class that I need data from.
Somehow, the datatemplate from my xaml document is not recognised which results in a default template instead of the one I defined.
My template looks like this:
<DataTemplate x:Key="Tiled">
<StackPanel Height="100" Width="90">
<Grid Width="70" Height="70" HorizontalAlignment="Center">
<Image Source="{Binding Path=Content.Icon}" Margin="6,6,6,9"/>
</Grid>
<TextBlock Style="{Binding Path=Content.Name}" FontSize="13"
HorizontalAlignment="Center" Margin="0,0,0,1" />
</StackPanel>
</DataTemplate>
I know that I can also set the source of the list to a collection of objects instead of listviewitems, but I need the contextmenu from the listviewitems.
I know that I can also set the source of the list to a collection of objects instead of listviewitems, but I need the contextmenu from the listviewitems.
No you don't, that's what the ItemContainerStyle is for.
What you by the way should see in the output window:
System.Windows.Data Error: 26 : ItemTemplate and ItemTemplateSelector are ignored for items already of the ItemsControl's container type; Type='ListBoxItem'
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.
I have a list box which is of a certain fixed width. The number of items in the listbox varies. Is there a way to center the contents of the list box? The "Content Presenter" of the ListBoxItem ,centers each item inside its Template instead of centering it with respect to the entire listbox width.
Sorry about not replying earlier. The issue was with the width of the ItemsPanelTemplate which I was using in my Listbox. Earlier Width was set to 925. Changing this Width to MaxWidth worked. The code:
<ItemsPanelTemplate x:Key="ItemsPanelKey">
<Contact:AnimatedWrapPanel HorizontalAlignment="Center" MaxWidth="925">
<Contact:AnimatedWrapPanel.Interpolation>
<interpolate:BackInterpolation Amplitude=".5" Suppression=".2" EdgeBehavior="5"/>
</Contact:AnimatedWrapPanel.Interpolation>
</Contact:AnimatedWrapPanel>
</ItemsPanelTemplate>
Not sure, but sounds like what you want is a custom item template that centers each item. If I'm right, the only tricky thing is that the template has to be the same fixed width as the listbox. So if your listbox contains some object Foo and Foo.Text is a simple text property to be displayed, you could do it like so in Xaml:
<ListBox x:Name="TheListBox" Width="300">
<ListBox.ItemTemplate>
<DataTemplate>
<Grid Width="300">
<TextBlock Text="{Binding Text}" HorizontalAlignment="Center" />
</Grid>
</DataTemplate>
</ListBox.ItemTemplate>
</ListBox>
and the code behind contains something like:
List<Foo> ListOfFoo = new List<Foo>();
ListOfFoo.Add(new Foo(){Text="Something"});
ListOfFoo.Add(new Foo(){Text="Something Else"});
ListOfFoo.Add(new Foo(){Text="Something Completely Different"});
TheListBox.ItemsSource = ListOfFoo;
If it's more complex or you can't make it work, post some code and we'll go from there.
I've modified my question since it has changed focus when trying things out.
I narrowed the problem down to the following...
I try to bind the selected Item of a TreeView to a StackPanel (or some other container that can hold User Controls). This container will then display a UserControl, depending on the type of the selected item.
Here is the xaml of the StackPanel (both treeview and stackpanel are in the same window ==> different grid column)
<StackPanel Grid.Column="2" MinWidth="500" DataContext="{Binding ElementName=myTree, Path=SelectedItem, Mode=OneWay}">
<StackPanel.Resources>
<DataTemplate DataType="{x:Type mvTypes:MyTypeA}">
<controls:UserControlA DataContext="{Binding}" />
</DataTemplate>
<DataTemplate DataType="{x:Type mvTypes:MyTypeB}">
<controls:UserControlB DataContext="{Binding}" />
</DataTemplate>
</StackPanel.Resources>
</StackPanel>
When I place a user control directly under the stackpanel (not in the resources), it displays it with the selected object as their datacontext.
Idem if I place a TextBox in it, it will show the correct type of the selected item.
<TextBox Name="textBox1" Text="{Binding}" />
For some reason, placing it within a DataTemplate (even without setting the DataType) results in nothing to display.
Any sugestions. I'm thinking that maybe a StackPanel is not the right control for this, though I can't seem to find other controls that look suitable as containers like this.
Thanks in advance.
Replace the StackPanel in your example with ContentPresenter and instead of DataContext set the Content property. That should work.
Although you have set the Binding on the second custom control, are you setting the DataContext, as the binding is the route to the information and the DataContext is the information it applies this binding information to.
Andrew
You can create a UserControl to display the TreeView and the selection info on the right, all in one. It saves you from creating any custom control. A custom control is basically unnecessary since you do not create anything which didn't exist before.
<UserControl x:Class="NameSpace.SelectionView"
xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
xmlns:controls="namespace.Controls"
Height="300" Width="300">
<Grid>
<Grid.ColumnDefinitions>
<ColumnDefinition/>
<ColumnDefinition/>
</Grid.ColumnDefinitions>
<TreeView Name="customTree">
<!--Items go here-->
</TreeView>
<StackPanel Grid.Column="1" MinWidth="50" DataContext="{Binding ElementName=customTree, Path=SelectedItem, Mode=OneWay}">
<StackPanel.Resources>
<DataTemplate DataType="{x:Type StylingTest:CustomViewModelA}">
<controls:CustomADetailsControl />
</DataTemplate>
<DataTemplate DataType="{x:Type StylingTest:CustomViewModelB}">
<controls:CustomBDetailsControl />
</DataTemplate>
</StackPanel.Resources>
<TextBlock Text="{Binding}"/>
</StackPanel>
</Grid>
</UserControl>
Any other custom behaviour, I'm sure you could create or set in styles/templates here.
Also, you might find one of my other answers useful.
Good luck with wpf, cheers.
This is a XAML code sample taken from the MSDN library article for the ItemsControl.ItemTemplate property:
<ListBox Width="400" Margin="10" ItemsSource="{Binding Source={StaticResource myTodoList}}">
<ListBox.ItemTemplate>
<DataTemplate>
<StackPanel>
<TextBlock Text="{Binding Path=TaskName}" />
<TextBlock Text="{Binding Path=Description}"/>
<TextBlock Text="{Binding Path=Priority}"/>
</StackPanel>
</DataTemplate>
</ListBox.ItemTemplate>
</ListBox>
I'm looking for an explanation of the usage of the <StackPanel> element is this example.
->
Where is this panel going to exist in the ListBox?
What is its purpose in the ItemTemplate?
Can any System.Windows.Controls.Panel be used in its place, specifically a Grid?
How would I go about using a <Grid> element as the template for each item in the ListBox?
Here is the concept I am going for:
http://img151.imageshack.us/img151/7960/graphconcept.png
I have drawn the graph using a <Path> element, and there are no problems there.
I am working on the labels for the axies, and I am experimenting with the use of a <Grid> element in the ItemTemplate - but I have no idea how the grid is supposed to function in this context, and MSDN says nothing about the panel in their sample code.
My XAML for the Y-axis labels currently looks like this:
<ListBox Background="Transparent" BorderThickness="0" ItemsSource="{Binding Path=GraphLabelYData}">
<ListBox.ItemTemplate>
<DataTemplate>
<Grid>
<Grid.RowDefinitions>
<RowDefinition Height="{Binding Path=GraphLabelSpacing}" />
</Grid.RowDefinitions>
<Grid.ColumnDefinitions>
<ColumnDefinition Width="Auto" />
<ColumnDefinition Width="{Binding ElementName=GraphLabelYData, Path=GraphLabelMarkerLength}" />
</Grid.ColumnDefinitions>
<TextBlock HorizontalAlignment="Right" VerticalAlignment="Bottom" Text="{Binding Path=GraphLabelTag}" />
<Rectangle Grid.Column="1" HorizontalAlignment="Stretch" VerticalAlignment="Bottom" Stroke="Black" Fill="Black" />
</Grid>
</DataTemplate>
</ListBox.ItemTemplate>
</ListBox>
Does this look correct? Nothing shows up at run-time, but I want to make sure the XAML is modeled correctly before I start debugging the data-bindings and the code-behind.
"Where is this panel going to exist in the ListBox?" - The listbox will make one copy of it for each list item, i.e. one for each element in the myTodoList collection. So within each list item, you'll have the three labels stacked one above the other.
"What is its purpose in the ItemTemplate?" - To make it possible to show more than one control for each element in the ItemsSource. ItemTemplate, like many things in WPF, can only take one child element, so if you want multiple children, you need to specify how you want them laid out, and you do that by adding a panel (StackPanel in this case).
"Can any System.Windows.Controls.Panel be used in its place, specifically a Grid?" - You bet.
"How would I go about using a <Grid> element as the template for each item in the ListBox?" - The same way you would use a Grid anywhere else. It's no different; it's just that ItemsControl (and its descendant, ListBox) will create multiple instances of your Grid. Note, though, that inside the ItemTemplate, your DataContext will be the current list item, and therefore your {Binding}s will be relative to that list item (unless you specify otherwise with e.g. ElementName).
"Does this look correct?" - This really should be posted as a separate question, as it's unrelated to the questions about the MSDN sample, and I'm not even sure what you're trying to do. But I'll try to answer: I suspect something is wrong, because you're using the name "GraphLabelYData" two different ways. In the ColumnDefinition, as far as I can tell, you're treating GraphLabelYData as the name of a XAML element (i.e. you're looking for another control in the window/page/UserControl with Name="GraphLabelYData" or x:Name="GraphLabelYData", and reading that control's GraphLabelMarkerLength property); but in the TextBlock, you're treating GraphLabelYData as the name of a property on the current collection item. I suspect one of those isn't right.