I have a class thats created as a resource:
<Window.Resources>
<Model:MyModel x:Key="model" />
</Window.Resources>
The MyModel class has a cli property named Foo. I want the selected value in a combobox to be bound to this property. I thought I could do this but Im getting errors:
<ComboBox SelectedItem="{Binding Source={StaticResource model.Foo}}" />
Heres the error:
Cannot find resource named '{model.Foo}'.
Where did I go wrong? What extra parameters do I need to specify to properly bind to a subproperty?
You almost have it correct. You want to use a combination of the Binding's Path property and its Source property. So use one of the following (they are equivalent.)
{Binding Foo, Source={StaticResource model}}
or
{Binding Path=Foo, Source={StaticResource model}}
Hope this helps.
Related
I have a custom styled Combobox which works fine. It is placed inside a usercontrol and bound to a data structure. I use DisplayMemberPath to show only one element in the Combobox TextBox. The ComboBox Style is taken from MSDN and used many times. So it's not displayed here.
<UserControl x:Class="wpf.projext1.MyComboBox"
x:Name="MyControl"
...
<ComboBox Style="{StaticResource ComboBoxStyle}"
Text="{Binding ElementName=MyControl, Path=Text}"
IsEditable="True"
IsTextSearchEnabled="False"
StaysOpenOnEdit="True"
ItemsSource="{Binding ElementName=MyControl, Path=MyItemsSource}"
DisplayMemberPath="Name"
</ComboBox
I get the following annoying error message populating the output window:
System.Windows.Data Error: 25 : Both 'ContentTemplate' and 'ContentTemplateSelector' are set; 'ContentTemplateSelector' will be ignored. ComboBoxItem:'ComboBoxItem' (Name='')
if i leave out the
DisplayMemberPath="Name"
... no debug output about error 25 is shown. But I definitely need DiplayMemberPath="Name"!
Do You have an idea to fix this ?
You can´t set both DisplayMemberPath and ItemTemplate at the same time.
DisplayMemberPath is used to tell the ItemsControl which property to display when showing your objects. It makes no sense to set this field if you're already passing a custom ItemTemplate, since you can choose how to show the object within that ItemTemplate.
Since the default Combobox style from MSDN also sets an ItemTemplate, this is likely the cause of the error.
resolved: use the TextSearch attached property, no matter if TextSearch is enabled!
TextSearch.TextPath="Name"
Should note TextSearch.TextPath="Name" instead of DisplayMemberPath="Name".
For some reason I am unable to bind to ViewModel properties within DataTemplates on some controls. The result of the binding itself is unpredictable, sometimes it work, sometimes it doesn't. For this reason I am thinking of exposing the ViewModel in some other way besides setting it as DataContext.
First thought was to add ViewModel to Resources collection. I am using TabControls for UI, so whenever a view needs to be displayed, it is done through Data templates.
<DataTemplate DataType="{x:Type vm:SomeViewModel}">
<vw:SomeView />
</DataTemplate>
In this situation the view is instantiated automatically, and its DataContext is set to ViewModel set in template. Is there a way I can make this ViewModel available to View's Resources (ex with key=viewModel), so that I can use it like this:
<TextBlock Text="{Binding SomeProperty, Source={StaticResource viewModel}}" />
I have tried adding it in code, in the Loaded event for the View:
this.Loaded += (s, e) =>
{
this.Resources.Add("viewModel", this.DataContext);
};
Above code is executed before the error pops up that says static resource is not found at run-time, so the resource was added to collection.
Any ideas what can I do?
You can define ViewModel as a resource in XAML like that:
<vm:SomeViewModel x:Key="ViewModel"/>
If you want to Bind to DataContext in a DataTemplate you can use the following:
{Binding Path=DataContext, ElementName=uc}
assuming that your window/usercontrol name is x:Name="uc" , or as #stukselbax wrote:
{Binding Path=DataContext, RelativeSource={RelativeSource Mode=FindAncestor, AncestorType=[UserControl|Window]}}
I have a ComboBox in my wpf application.
It's ItemsSource is binded to some table in my DataSet.
I need the text property to be binded to another's object property . I doesn't work because the ComboBox doesn't want to get two DataContexts. How can I solve this problem?
<StackPanel Width="Auto" Height="Auto" MinWidth="296" Orientation="Vertical" x:Name="MyStackPanel">
<ComboBox x:Name="MyComboBox" ItemsSource="{Binding}" Text={Binding Path=MyProperty} />
</StackPanel>
In the code behind :
MyComboBox.DataContext = MyDataSet.Tables[MyTable];
MyStackPanel.DataContext = MyObject;
I want the ComboBox to show items from one DataContext but to show the text from another DataContext. How can I do it?
Don't use DataContext. Set the Source property of your bindings in XAML or create the bindings in code and set the Source property there.
Why are you assigning something to the datacontext of the stackpanel? From the looks of it, its not used.
Your code should work if MyDataSet.Tables[MyTable] returns an enumeration and contains a property called MyProperty.
What do you mean when you say that the combobox "doesn't want to get two DataContexts"?
Look into the properties IsEditable and IsReadOnly of the combobox.
Something like
<ComboBox x:Name="MyComboBox" ItemsSource="{Binding}" Text={Binding ElementName=MyStackPanel Path=DataContext.MyProperty} />
I want two comboboxes with collection with empty element.
I Use two comboboxes with:
<ComboBox x:Name="itemEditPageComboBox"
...
ItemsSource="{StaticResource ItemsColl}"
....
/>
Collections:
<CompositeCollection x:Key="ItemsColl">
<ComboBoxItem Content="" />
<CollectionContainer Collection="{Binding Source={StaticResource ElementsCollection}}" />
</CompositeCollection>
<CollectionViewSource x:Key="ElementsCollection" Source="{Binding Path=...}" />
behaviour
Sequentially choose two comboboxes, after it - one of them is removed empty element.
Error:
System.Windows.Data Error: 26 : ItemTemplate and ItemTemplateSelector are ignored for items already of the ItemsControl's container type; Type='ComboBoxItem'
Please tell me what to do?
Best regards!
You cannot use the same ComboBoxItem in two ComboBoxes, also the error should be quite clear: If you add a ComboBoxItem to a ComboBox which has an ItemTemplate defined, that won't be applied to that ComboBoxItem because it already has the type of the created containers. This error may or may not be a problem, depending on what you want.
If you want to use the collection for two ComboBoxes you should add a string or if you want something more complex an instance of a class (which should probably have an implicit DataTemplate associated with it). Do not add a ComboBoxItem directly.
I'm trying to bind the item selected in a RibbonComboBox to a property of an object. The problem I'm encountering is that the RibbonComboBox.SelectionBoxItem only provides a get accessor; therefore, I cannot bind it to anything in the XAML.
Any ideas how to bind the item to the property of an object? I could use a regular ComboBox is there another more appropriate control?
xmlns:ribbon="clr-namespace:Microsoft.Windows.Controls.Ribbon;assembly=RibbonControlsLibrary"
<ribbon:RibbonComboBox
ItemsSource="{Binding Source={StaticResource CollectionOfPossibleChoices}}"/
SelectionBoxItem="{Binding Path=PropertyToBindTo}"/> <!--Not valid-->
RibbonComboBox is unlike ComboBox (which i, also, find confusing). Try this;
<ribbon:RibbonComboBox>
<ribbon:RibbonGallery SelectedItem="{Binding Path=PropertyToBindTo}">
<ribbon:RibbonGalleryCategory ItemsSource="{Binding Source={StaticResource CollectionOfPossibleChoices}}" />
</ribbon:RibbonGallery>
</ribbon:RibbonComboBox>
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