In my Silverlight 4 application, I have a ContentControl with its ContentTemplate property bound to a property in the data context. That works fine. However, the content of the template once rendered has its DataContext set to null. I would like the content to inherit the same DataContext as set for the ContentControl. Is there a way to get this to happen?
The ContentControl's template has the ContentControl's Content property as a DataContext. So try
<ContentControl Content="{Binding}" />
if this is merely the current DataContext.
I found an alternate way to accomplish what was required. In my case, the template (not the content template) of the ContentControl was unimportant, so I made my DataTemplate objects into ControlTemplate objects instead and bound the Template property of the ContentControl instead of ContentTemplate. The data context was preserved if I did it this way.
Related
In my WPF app, I'm using several ContentPresenters with a special MarkupExtension that requires access to the ContentPresenter's ContentTemplate property.
The MarkupExtension works very well, except that I just found out that if a ContentPresetner uses a ContentTemplateSelector, it doesn't set its own ContentPresenter property: rather, both the ContentPresenter and the result of the ContentTemplateSelector get saved to a private variable of the ContentPresenter class, as can be seen here: link to .Net source code for ContentPresenter.
I figured out that I can call ContentTemplateSelector.SelectTemplate() again and get the template, or keep a dictionary of selected templates inside the ContentTemplateSelector so that I can fetch the template that was geneatedfor each element, but is there a better way to do this?
i need to send a DataTemplate to a new window for printing purposes.
1) I have create a general Window lets name it PrintPreview that holds the followings:
FlowDocument > BlockUiContainer > ContentControl (Responsible to display the DataTemplate that i will send to it)
The problem is that the bindings inside the datatemplate are not working. (not for all cases )
For example:
i have this datatemplate somewhere in my application
<DataTemplate x:Key="MyPrintPreview">
<DockPanel>
<TextBlock Text="{Binding SomeProperty1,RelativeSource={RelativeSource AncestorType=UserControl}}"></TextBlock>
<TextBlock Text="{Binding Source={StaticResource SomeViewModel},Path=SomeProperty2}"></TextBlock>
</DockPanel>
</DataTemplate>
The above DataTemplate is working very well and show both properties in my current View (UserControl)
but when i send this DataTemplate to the New Window PrintPreview i have the following issues
The 1st TextBlock (SomeProperty1) fails to display the content
The 2nd TextBlock (SomeProperty2) show just fine!
i don't know how to make this work. or if am doing it the wrong way?
You should set or bind the Content property of the ContentControl to an object that contains the properties that the elements in the ContentTemplate try to bind to.
So set the ContentTemplate property of the ContentControl to your DataTemplate and set the Content property to the actual object to bind to. That's how a ContentControl is supposed to be used.
Also note that for your first binding to work, the ContentControl must be a child of a UserControl because you are binding to SomeProperty1 of the parent UserControl. If there is no parent UserControl, the binding will always fail.
I'm trying to bind combobox editor in a PropertyGrid to a list.
<dxprg:PropertyGridControl SelectedObject="{Binding SelectedEmployee}">
<dxprg:PropertyDefinition Path="EmployeeCountryID">
<dxprg:PropertyDefinition.EditSettings>
<dxe:ComboBoxEditSettings
ItemsSource="{Binding Path=DataContext.Countries, ElementName=rootWindow}"
ValueMember="CountryId" DisplayMember="CountryName" />
</dxprg:PropertyDefinition.EditSettings>
</dxprg:PropertyDefinition>
</dxprg:PropertyGridControl>
This example is from a third-party control but the problem may be just general.
The "rootWindow" DataContext has been set to a ViewModel which holds a property List(of Country) that I want have as ItemsSource in a Combobox.
I was trying to access that list by setting the Combobox ItemsSource to the rootWindow.DataContext.Countries property but I don't get any data.
Tried also all those RelativeSource FindAncestor bindings but no data appeared either.
Why can't I bind through a DataContext of a given element like this?
This became solved. The problem was not with the binding at all but realated to how I defined the third-party control: Instead of EditSettings I should have defined CellTemplate -> DataTemplate.
In a WPF Custom Control template, is there any way that I can do the following in XAML?:
var selItemText = this.GetTemplateChild("PART_SelectedItemText") as TextBlock;
var binding = new Binding("SelectedItem." + DisplayMemberPath);
binding.RelativeSource = new RelativeSource(RelativeSourceMode.TemplatedParent);
selItemText .SetBinding(TextBlock.TextProperty, binding);
Note that the interesting part of this statement is the binding constructor - I am building up a path based on both some text I specify ("SelectedItem."), and the path provided by the user.
The consumer would use the control similar to:
<c:MyControl DisplayMemberPath="Description" />
short answer: no, it's not possible to get this entirely in xaml within the controltemplate
your possibilities are:
use what you have (possibly using attached properties / a behavior to make it more MVVM-like)
use a MultiBinding one binding to the "SelectedItem" the other to "DisplayMemberPath" and your MultiValueConverter using Reflection to reflect down the DisplayMemberPath (may be a bit ugly)
create a class that inherits from Binding and exposes Properties that you can bind the DisplayMemberPath to and changes the underlying Binding (read here for how you can do this) (complicated)
use Reflection to instantiate a MS.Internal.Data.DisplayMemberTemplateSelector / build something similar
think about if your design is right. Other than your Control being some kind of ItemsControl (if that was the case you should inherit from ItemsControl and use the DisplayMemberPath you get there), I don't see why you shouldn't use a Binding on the outside like <c:MyControl DisplayMember="{Binding SelectedItem.Description}" /> and in your ControlTemplate use a TemplateBinding to bind to "DisplayMember"
You can split it to two different bindings. Have SelectedItem binds to a toplevel control of TextBlock and TextBox.Text bind to DisplayMemberPath as TemplateBinding.
I've seen this syntax show up, and have tried to google for it's definition to no avail; what does it mean when a dp is bound this way?
<Grid>
<ContentControl Content="{Binding}"/>
</Grid>
I was under the assumption that you have to bind to some property on the DataContext, or another element, but this appears to bind to nothing.
I believe it means you are binding to the root of whatever the binding context is. So if you use this syntax in a datatemplate that is part of some sort of list control, you would be binding to the root level of whatever the parent control (the list control) was binding to.
I believe {Binding} refers to the DataContext itself.
edit (clarification): By DataContext I mean the current level DataContext. For example, if your window's DataContext is bound to a List, then setting ItemsSource on a ListBox control in your window to {Binding} would bind the ListBox to the List itself, not a property of the List, like Count.
{Binding} is for {Binding [CurrentDataContext]}
{Binding} means that you want to Bind to the the current DataContext which could be set on the object itself. If no DataContext is set on the current object, then it will walk up the VisualTree and find the closest Parent that has a DataContext.