Develop Reference

Best practice adding UserControl to parent control via binding

I have an ObservableCollection<ControlMachine> where each ControlMachine is a UserControl used to display information about one computer.
public static ObservableCollection<ControlMachine> ListControleMachine =
new ObservableCollection<ControlMachine>();
I've tried to display the collection using binding
<Grid ForceCursor="True" x:Name="grid2" OpacityMask="{x:Null}" Margin="10,38,10,10" Background="#FFF5F6F6">
<ItemsControl ItemsSource="{Binding ListControleMachine}">
<ItemsControl.ItemTemplate>
<DataTemplate DataType="{x:Type Brush}">
<Rectangle Canvas.ZIndex="3" Width="100" Height="100" Canvas.Top="100" Canvas.Left="100" Fill="blue"/>
</DataTemplate>
</ItemsControl.ItemTemplate>
</ItemsControl>
</Grid>
My user control is not showing in the Grid with this code. What's wrong?
Question: What is the best practice for dispose such ControlMachine one under the others?.
Those ControlMachine can be closed and expanded and I can't find a clean way to update the user controls position for any case.
annexe: Do you think it's good-practice using UserControl in this case or may be I should use a Template or StackPanel?
How would you implement this?

Best practice for this solution is using a ViewModel instead of UserControl and bind it in your grid.
you can use DependencyProperty and INotifyPropertyChanged for two way binding in your ViewModel.
So you'll not warn about disposing ... .

ContentPresenter in ItemControl.ItemTemplate to show displaymemberpath of itemscontrol

I want to know is there anyway to put contentpresenter in itemtemplate of an itemscontrol to display my data. I don't want hard code binding like Text="{Binding username}" cause I am building a custom control, I think ContentPresenter is what I want. But after I tried using contentpresenter, it give me stackoverflowexception.
<ItemsControl ItemsSource="{Binding SelectedItems, ElementName=listbox}" DisplayMemberPath={Binding DisplayMemberPath}">
<ItemsControl.ItemPanel>
<ItemsPanelTemplate>
<StackPanel Orientation="Horizontal" IsItemsHost="True"/>
</ItemsPanelTemplate>
</ItemsControl.ItemPanel>
<ItemsControl.ItemTemplate>
<DataTemplate>
<StackPanel Orientation="Horizontal">
<TextBlock x:Name="Separator" Text=", "/>
<ContentPresenter/>
<!--<TextBlock Text="{Binding username}"/>-->
</StackPanel>
</DataTemplate>
</ItemsControl.ItemTemplate>
</ItemsControl>
That's my code.
If without those seperator and itemtemplate, I able to display my data by just using the displaymemberpath, but it stack all the name together. I still finding any solution to solve it. I hope you can provide some ideas to do this.

The answer is no, you can't. A ContentPresenter is supposed to be used in a ControlTemplate, not a DataTemplate, so it is not the right control to use. From the linked page on MSDN:
You typically use the ContentPresenter in the ControlTemplate of a ContentControl to specify where the content is to be added.
What you can do alternatively, is to declare a number of DataTemplates in a Resources section (complete with Binding Paths) for different types of data and omit the x:Key directives, eg. do not name them. Also, do not specify one for the ItemsControl.ItemTemplate.
When doing this, WPF will implicitly select the correct DataTemplate for the relevant data type and so you can have different outputs for different data types. See the The DataType Property section of the Data Templating Overview page on MSDN for further explanation of this technique.

Yes, and it works well. Outside of a ContentControl's template, you must bind the Content by hand:
<ContentPresenter Content="{Binding username}"/>
I do this a great deal and it never misbehaves. ContentPresenter seems to be implemented for general use. I wonder if the API docs overstate its relationship to ContentControl.

I found an easier way to solve this problem by using horizontal listbox. Thanks for responses

How to set a value through binding for a Windows Forms UserControl in XAML?

I'm dealing with this situation. I've got an items control where as item template I've got a windows forms userControl, and in code behind I'm setting the ItemsSource, but I don't know to set some data in the userControl.
In it UserControl I have some datagridview with specific structure, and WPF grid view is not useful for me. So I can't change this usercontrol.
<ItemsControl x:Name="itemsControl">
<ItemsControl.ItemTemplate>
<DataTemplate>
<WindowsFormsHost x:Name="wfh" Grid.Column="2" Margin="10,0,0,10" />
<local:StudentHistoryUserControl />
</WindowsFormsHost>
</DataTemplate>
</ItemsControl.ItemTemplate>
</ItemsControl>
What can I do to access that usercontrol and set some values?

Databinding in WindowsForms and WPF Hybrid Apps
Because Windows Forms is involved, XAML databinding will not work entirely. You need to set up data binding in the code behind.

Accessing a list picker inside a PanoramaHeader Template

I have a panorama control in which I have create a header template to add a list picker inside it. (Just like the peoples hub to select social accounts)
<DataTemplate x:Key="PanoramaItemHeaderTemplate">
<ContentPresenter>
<StackPanel Height="129">
<TextBlock Text="{Binding}" FontSize="72" Margin="0,7,0,0" />
<toolkit:ListPicker x:Name="listPick" Margin="0,-21,0,0" BorderThickness="0">
<toolkit:ListPickerItem Content="twitter"></toolkit:ListPickerItem>
</toolkit:ListPicker>
</StackPanel>
</ContentPresenter>
</DataTemplate>
The panorama control is inside the MainPage.xaml file and I want to have access to the listpicker from the code behind to be able to populate it, and handle it selection events.
I don't know how to do this. I tried adding the x:name property to the list picker I don't have access to it in the MainPage code behind.
Any idea on how to approach this is very welcomed, thanks!

From what you have now, the quickest way to do what you want is to traverse the visual tree
See here for the implementation:
How to access a specific item in a Listbox with DataTemplate?

You cannot access the ListPicker by x:Name because it is not unambiguous: there is a ListPicker generated for each PanoramaItem in your Panorama. So the first question is, is it really the think you want to do? If so you need to populate it using a binding (ItemSource)

You can access an element inside another resource, consider this example:
<Grid Name="myGrid">
<StackPanel x:Name="stack1">
<TextBlock x:Name="abc"/>
</StackPanel>
</Grid>
We can only access the Grid myGrid in code by default. To get reference to the StackPanel we can do this:
StackPanel myStack=myGrid.FindName("stack1") as Stackpanel;
After that we can get reference to the TextBlock:
TextBlock myTextBlock=myStack.FindName("abc") as TextBlock;
You can modify myTextBlock after that as you may like. You can apply the same technique in your case and it will work.
Hope that helps :).

TextBlock Text-Binding from ListView items

How can I change the Text of a TextBlock when the selection in my ListView changes?
I don't want do this manually...
All Items of the ListView are LogEntry's (class)... Can I use Binding in the Text-Attribute of the TextBlock to get a specific property of the selected Item?

Yes, in fact there are multiple solutions, i give you the most "WPF" like answer, but imo also the least flexible.
First you need to set the IsSynchronizedWithCurrentItem="True" property
Now if you select an item, the bound CollectionView will set the item as the CurrentItem.
Now your TextBox/Block can bind to this specific item via a special binding syntax using a '/'.
For Example:
<TextBlock Text="{Binding LogEntries/}"/>
of course you can get a specific property from the current item via binding aswell
<TextBlock Text="{Binding LogEntries/WarningMessage}"/>
Hope that helps.

assuming you have a listview like this:
<ListView ItemSource="{Binding LogEntries}" Name="logs" IsSynchronizedWithCurrentItem="True">
</ListView>
<ContentControl Content="{Binding ElementName=logs, Path=SelectedItem}" ContentTemplate="{StaticResource logTemplate}"/>
Now you need to provide that logTemplate in the Resources.
<UserControl.Resources>
<DataTemplate DataType="{x:Type local:LogEntry}">
<TextBlock Text="{Binding Path=LogText}"/> <-- This is a Property-Binding of your custom class
</DataTemplate>
</UserControl.Resources>
The last thing missing is to provide the namespace to your local class LogEntry. If you use an awesome tool like Resharper, it will insert the namespace for you. Otherwise, here a sample declaration:
<UserControl xmlns:local="clr-namespace:My.App.Namespace.LogEntry;assembly=My.App"
... (rest of namespace declarations)