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uwp: how to bind data inside DataTemplate outside of x:DataType?

i have MyPage.xaml and MyPage.xaml.cs files.
Into .xaml file i written a data template like this:
<DataTemplate x:Key="MyDataTemplate" x:DataType="local:MyClass">
...
<TextBlock Text="{x:Bind name}" HorizontalAlignment="Left" TextWrapping="Wrap"/>
...
</DataTemplate>
I can bind name attribute of MyClass correctly.
Now i need to bind an attribute of .xaml.cs file but DataTemplate show me only MyClass data. How can i bind data from .xaml.cs page? Outside DataTemplate (but in the same xaml file) i can see any attribute of .xaml.cs file.
I need to bind a List of objects to a combobox like this:
<ComboBox ItemsSource="{x:Bind myList}" HorizontalAlignment="Left"></ComboBox>
but myList is an .xaml.cs attribute.
I want to view a string name attribute of objects of the list.
Thank you for your help

uwp: how to bind data inside DataTemplate outside of x:DataType?
For your recrement, we suggest you use Binding to replace x:Bind, You could use Binding to access current root DataContext with ElementName.
For example
<Grid x:Name="GridRoot">
<ListView ItemsSource="{Binding Items}">
<ListView.ItemTemplate>
<DataTemplate>
<StackPanel Orientation="Horizontal">
<TextBlock Text="{Binding Name}" />
<ComboBox ItemsSource="{Binding ElementName=GridRoot, Path=DataContext.Options}" />
</StackPanel>
</DataTemplate>
</ListView.ItemTemplate>
</ListView>
</Grid>
Code Behind
public sealed partial class MainPage : Page
{
public MainPage()
{
this.InitializeComponent();
this.DataContext = this;
}
public List<string> Options { get; set; } = new List<string>() {"One","Two","Three" };
public List<Item> Items { get; set; } = new List<Item>()
{
new Item { Name = "HH" },
new Item { Name = "ZZ" },
new Item { Name = "MM" }
};
}
public class Item
{
public string Name { get; set; }
}

Changing the ViewModel's property from another ViewModel

I have the ListBox on my MainView.xaml, selecting the Item forces the ContentControl to display different UserControls. I use Caliburn.Micro library in this propgram. Here's some code:
<ListBox Grid.Row="1" Grid.Column="1" x:Name="ItemsListBox" SelectedItem="0" ItemsSource="{Binding Items}">
<ListBox.ItemTemplate>
<DataTemplate>
<TextBlock Text="{Binding Name}" />
</DataTemplate>
</ListBox.ItemTemplate>
</ListBox>
<TextBlock Grid.Row="2" Grid.Column="1" Text="{Binding TextBlock1Text}" x:Name="TextBlock1"/>
<ContentControl Grid.Row="3" Grid.Column="1" Content="{Binding ElementName=ItemsListBox, Path=SelectedItem.Content}" />
The MainViewModel.cs:
private string _name;
public string Name
{
get => _name;
set
{
_name = value;
NotifyOfPropertyChange(() => Name);
}
}
private string _textBlock1Text;
public string TextBlock1Text
{
get => _textBlock1Text;
set
{
_textBlock1Text = value;
NotifyOfPropertyChange(() => TextBlock1Text);
}
}
public MainViewModel()
{
TextBlock1Text = "Test";
Items = new ObservableCollection<ItemsModel>()
{
new ItemsModel { Name="Useless", Content=null },
new ItemsModel { Name="TextChangerViewModel", Content=new TextChangerViewModel(TextBlock1Text) }
};
}
public ObservableCollection<ItemsModel> Items { get; set; }
The ItemsModel.cs:
public class ItemsModel
{
public string Name { get; set; }
public object Content { get; set; }
}
And finally the TextChangerViewModel.cs:
public class TextChangerViewModel : Conductor<object>
{
private string _textBlock1Text;
public string TextBlock1Text
{
get => _textBlock1Text;
set
{
_textBlock1Text = value;
NotifyOfPropertyChange(() => TextBlock1Text);
}
}
public TextChangerViewModel(string textBlock1Text) //passing parameter from another ViewModel
{
TextBlock1Text = textBlock1Text;
}
}
So, the main question is how to change the TextBlock1Text (and the Text value of TextBlock in .xaml as well) in the MainViewModel.cs from the TextChangerViewModel.cs? I was thinking about using something like NotifyCollectionChanged on my Items ObservableCollection, but it work with collection of ItemsModel, not with the VM's, so I'm stuck here.
I'm also not sure if having public object Content { get; set; } in ItemsModel.cs is a good thing if I'm targeting the MVVM pattern, but I don't know the other way to do it (I'm very new to MVVM).
UPD
I'm looking for the property-changing way because I need to change the TextBlock1Text Text from another UserControl. Suppose I have the button on my TextChangerView.xaml: <Button Grid.Row="0" HorizontalAlignment="Stretch" VerticalAlignment="Stretch" Content="Change da text" cal:Message.Attach="ChangeTextButton"/>
And after the click on it I want the text on the parental MainView.xaml to change. But the thing is, I don't know how to change properties in this case, as I wrote above why.

Change the the binding of textblox1 to reference the selected item.
<TextBlock Grid.Row="2" Grid.Column="1" Text="{Binding ElementName=ItemsListBox, Path=SelectedItem.Name}" x:Name="TextBlock1"/>
or
<TextBlock Grid.Row="2" Grid.Column="1" Text="{Binding ElementName=ItemsListBox, Path=SelectedItem.Content.TextBlock1Text}" x:Name="TextBlock1"/>

Populate a Tree View with a Custom List Object

I have a custom object that consists of 2 properties. The first is a string that i wish to use as a summary or header in the tree view. The second is a list of a custom type that contains objects that are to be included under each header. The objects contain things such as name, id, area, etc.. Ill most likely default to the name property of those list objects. How can I push this into a tree view.
Concatenated Model
public class WVWellModel : Notifier
{
private string _API;
public string API
{
get
{
return this._API;
}
set
{
this._API = value; OnPropertyChanged("API");
}
}
private string _WellName;
public string WellName
{
get
{
return this._WellName;
}
set
{
this._WellName = value; OnPropertyChanged("WellName");
}
}
private string _Division;
public string Division
{
get
{
return this._Division;
}
set
{
this._Division = value; OnPropertyChanged("Dvision");
}
}
private string _Area;
public string Area
{
get
{
return this._Area;
}
set
{
this._Area = value; OnPropertyChanged("Area");
}
}
private string _FieldOffice;
public string FieldOffice
{
get
{
return this._FieldOffice;
}
set
{
this._FieldOffice = value; OnPropertyChanged("FieldOffice");
}
}...............
** Model that will be put in a list to be injected into tree view**
public class groupingModel : Notifier
{
private string _Header;
public string Header
{
get { return _Header; }
set { _Header = value; OnPropertyChanged("Header"); }
}
private List<WVWellModel> _Wells;
public List<WVWellModel> Wells
{
get { return _Wells; }
set { _Wells = value; OnPropertyChanged("Wells"); }
}
}
List of Custom Type to be injected into tree view
List treeViewList = someMethod();
In summary, I would like to bind my tree view to a custom list object.List<groupingModel> The object in those lists have two properties, a string header that is to be used to group the objects in the tree view, and a second property that contains a list of custom objects "WVWellModel".
EDIT TO XAML to Allow Selection of all items in group
I've attempted to go ahead and make the group selectable with he goal that if the group is selected all children are selected underneath. Ive successfully bound it to a property inside of the group called "IsChecked". it defaults to false and works successfully. The problem is i am unable to capture the change in value and thus cannot run any logic to select its children.
<TreeView DockPanel.Dock="Bottom" ItemsSource="{Binding Groups}">
<TreeView.ItemTemplate>
<HierarchicalDataTemplate DataType="wellModel:WellGroupModel" ItemsSource="{Binding Wells}">
**<CheckBox Content="{Binding Header}" IsChecked="{Binding IsChecked}"/>**
<HierarchicalDataTemplate.ItemTemplate>
<DataTemplate DataType="{x:Type wellModel:WellModel}">
<CheckBox Content="{Binding WellName}" IsChecked="{Binding IsSelected}" />
</DataTemplate>
</HierarchicalDataTemplate.ItemTemplate>
</HierarchicalDataTemplate>
</TreeView.ItemTemplate>
</TreeView>

The TreeView control uses HierarchicalDataTemplate to control how items are displayed and how their children are populated. If your item class has children of a different type, it can specify its own child ItemTemplate, and so on recursively.
I've also added a minimal top-level viewmodel which owns a collection of GroupingModel. I'm using conventional C# naming conventions: Classes and properties start with a capital letter, private fields start with an underscore and a lower-case letter. It seems silly but when everybody uses the same convention, you always know what you're looking at.
Finally, I used ObservableCollection<T> rather than List<T>. If you bind an ObservableCollection to a control, then you can add/remove items in the collection and the control will automatically be notified and update itself without any additional work on your part.
XAML
<TreeView
ItemsSource="{Binding Groups}"
>
<TreeView.ItemTemplate>
<HierarchicalDataTemplate
DataType="{x:Type local:GroupingModel}"
ItemsSource="{Binding Wells}"
>
<TextBlock Text="{Binding Header}" />
<HierarchicalDataTemplate.ItemTemplate>
<!-- This can be DataTemplate if no child collection is specified -->
<DataTemplate
DataType="{x:Type local:WVWellModel}"
>
<TextBlock Text="{Binding WellName}" />
</DataTemplate>
</HierarchicalDataTemplate.ItemTemplate>
</HierarchicalDataTemplate>
</TreeView.ItemTemplate>
</TreeView>
Alternatively, if you have heterogeneous collections of objects, you can create implicit templates as resources and let them be applied by type rather than by hierarchy. In your particular case, this will produce identical results, because you have a strict item hierarchy.
<TreeView
ItemsSource="{Binding Groups}"
>
<TreeView.Resources>
<HierarchicalDataTemplate
DataType="{x:Type local:GroupingModel}"
ItemsSource="{Binding Wells}"
>
<TextBlock Text="{Binding Header}" />
</HierarchicalDataTemplate>
<DataTemplate
DataType="{x:Type local:WVWellModel}"
>
<TextBlock Text="{Binding WellName}" />
</DataTemplate>
</TreeView.Resources>
</TreeView>
C#
public class ViewModel : Notifier
{
public ViewModel()
{
Groups = new ObservableCollection<GroupingModel>
{
new GroupingModel {
Header = "First Group",
Wells = new List<WVWellModel> {
new WVWellModel() { WellName = "First Well" },
new WVWellModel() { WellName = "Second Well" },
new WVWellModel() { WellName = "Third Well" },
}
},
new GroupingModel {
Header = "Second Group",
Wells = new List<WVWellModel> {
new WVWellModel() { WellName = "Third Well" },
new WVWellModel() { WellName = "Fourth Well" },
new WVWellModel() { WellName = "Fifth Well" },
}
}
};
}
#region Groups Property
private ObservableCollection<GroupingModel> _groups = new ObservableCollection<GroupingModel>();
public ObservableCollection<GroupingModel> Groups
{
get { return _groups; }
set
{
if (value != _groups)
{
_groups = value;
OnPropertyChanged(nameof(Groups));
}
}
}
#endregion Groups Property
}
Update
Let's make the WVWellModel items checkable. First, we'll give them a boolean property that we'll bind to the checkbox's IsChecked property:
public class WVWellModel : Notifier
{
private bool _isSelected;
public bool IsSelected
{
get
{
return this._isSelected;
}
set
{
this._isSelected = value; OnPropertyChanged();
}
}
And then we'll change the content in the WVWellModel DataTemplate from a TextBlock to a CheckBox:
<DataTemplate
DataType="{x:Type local:WVWellModel}"
>
<CheckBox
Content="{Binding WellName}"
IsChecked="{Binding IsSelected}"
/>
</DataTemplate>
You can put any valid XAML UI in a template as long as there's a single root element.
<TreeView
Width="300"
Height="200"
ItemsSource="{Binding Groups}"
Grid.IsSharedSizeScope="True"
>
<TreeView.Resources>
<HierarchicalDataTemplate
DataType="{x:Type local:GroupingModel}"
ItemsSource="{Binding Wells}"
>
<TextBlock Text="{Binding Header}" />
</HierarchicalDataTemplate>
<DataTemplate
DataType="{x:Type local:WVWellModel}"
>
<Grid>
<Grid.ColumnDefinitions>
<ColumnDefinition Width="Auto" SharedSizeGroup="CheckBoxColumn" />
<ColumnDefinition Width="Auto" SharedSizeGroup="APIColumn" />
</Grid.ColumnDefinitions>
<CheckBox
Grid.Column="0"
Content="{Binding WellName}"
IsChecked="{Binding IsSelected}"
/>
<TextBlock
Grid.Column="1"
Margin="12,0,0,0"
Text="{Binding API}"
HorizontalAlignment="Right"
/>
</Grid>
</DataTemplate>
</TreeView.Resources>
</TreeView>

Binding an entire collection object and subproperties without setting DataContext

I´m trying to bind a ListBox to a ObservableCollection. I wan´t to bind the Text Properties of the ListBox entrys and the Background of the ListBox entrys.
The ListBox is defined in an loaded loose xaml file:
<TextBox Margin="0,5,5,5" Text="{Binding Path=TB9P}" Background="LightBlue" Name="DetailsviewTB9" Height="20">
<TextBox.ToolTip>
<StackPanel>
<Label FontWeight="Bold" Background="Blue" Foreground="White">Daten</Label>
<ListBox ItemsSource="{Binding Source={StaticResource res_LB1P}}">
<ListBox.ItemTemplate>
<DataTemplate>
<TextBlock Text="{Binding Path=StringP}" Background="{Binding Path=SelectedItemP, Converter={StaticResource c_SelectedItemToBackgroundConverter}}"/>
</DataTemplate>
</ListBox.ItemTemplate>
</ListBox>
</StackPanel>
</TextBox.ToolTip>
</TextBox>
The DataContext is set on class DetailsViewText
public class LBEntry
{
bool DetailsViewLBSelectedItem = true;
string DetailsViewLB = "test";
public LBEntry(bool selcected, string str)
{
DetailsViewLB = str;
DetailsViewLBSelectedItem = selcected;
}
public bool SelectedItemP
{
get { return DetailsViewLBSelectedItem; }
set { DetailsViewLBSelectedItem = value; }
}
public string StringP
{
get { return DetailsViewLB; }
set { DetailsViewLB = value; }
}
}
public class LBEntrysCollection : System.Collections.ObjectModel.ObservableCollection<LBEntry>
{
//
}
public class DetailsViewText
{
string[] DetailsViewTB1_Text = new string[20];
bool[] fDetailsViewCB = new bool[20];
LBEntrysCollection[] LBEntrys = new LBEntrysCollection[]{
new LBEntrysCollection{ new LBEntry(false, "test"), new LBEntry(true, "test") },
new LBEntrysCollection{ new LBEntry(true, "test") },
new LBEntrysCollection{ new LBEntry(false, "test") },
new LBEntrysCollection{ new LBEntry(false, "test") },
new LBEntrysCollection{ new LBEntry(false, "test") }
};
public LBEntrysCollection LB1P
{
get { return LBEntrys[0]; }
set { LBEntrys[0] = value; }
}
public string TB9P
{
get { return DetailsViewTB1_Text[8]; }
set { DetailsViewTB1_Text[8] = value; }
}
...
}
The resource res_LB1P is set in the mainWindow constructor:
// Resources
this.Resources.Add("res_LB1P", detailsViewFrameHandling.DetailsViewTextP.LB1P);
Basicly I just want to bind the ListBox to a LBEntrysCollection with SelectedItemP as switch for the background Color and StringP as the Text Property. But I need the DataContext on DetailsViewText for other Propertys.
I´m getting an Exception when the xaml File is loading the StaticResource res_LB1P.
How do I have to set my Binding on ListBox and TextBlock to get it right?
EDIT:
With this
<ListBox ItemsSource="{Binding Path=LB1P}">
<ListBox.ItemTemplate>
<DataTemplate>
<TextBlock Text="{Binding Path=LB1P.StringP}" />
</DataTemplate>
</ListBox.ItemTemplate>
</ListBox>
Items are added, but there is no Text shown in the TextBox
Now I´m really confused. It does work like this:
<ListBox ItemsSource="{Binding Path=LB1P}">
<ListBox.ItemTemplate>
<DataTemplate>
<TextBlock Text="{Binding Path=StringP}" Background="{Binding Path=SelectedItemBrushP}"/>
</DataTemplate>
</ListBox.ItemTemplate>
</ListBox>
Simple enough, but I thought i had tried this before and it didn´t work...
Is it possible, that if one Binding does fail (the Background Binding) the other Binding (Text Property) does also not work?

I have always considered the ViewModel (the object the DataContext points to) to be just that: a Model of the View.
So to solve this, you need either one object that will be the ViewModel because there is only one DataContext property or you will need to add an extra DataContext-like property.
The first option (one ViewModel) can be realized by creating a new class that contains both the ObservableCollection and the DetailsViewText:
class ComposedViewModel: INotifyPropertyChanged
{
public LBEntrysCollection LBEntries
{
get { ... }
set { ... }
}
public DetailsViewText Details
{
get { ... }
set { ... }
}
}
The second option (extra DataContext-like property) can be realized by sub-classing the ListBox and adding another property.

Why not do this ?
<ListBox ItemsSource="{Binding ElementName=<TextBox's Name>, Path=DataContext">
<ListBox.ItemTemplate>
<DataTemplate>
<TextBlock Text="{Binding Path=StringP}" Background="{Binding Path=SelectedItemP, Converter={StaticResource c_SelectedItemToBackgroundConverter}}"/>
</DataTemplate>
</ListBox.ItemTemplate>
</ListBox>
Correct me if I'm wrong with understanding your question. You want to bind the listbox's itemssource to the textbox's datacontext?

Problem with Silverlight binding

I have the following XAML:
...
<ListBox Name ="RoomsListBox" Height="100"
HorizontalAlignment="Left" Margin="12,41,0,0"
VerticalAlignment="Top" Width="120"></ListBox>
...
And the following C#-code:
protected override void OnNavigatedTo(NavigationEventArgs e)
{
RoomsListBox.ItemsSource = new[] { new { Name = "First1" },
new { Name = "First2" } };
RoomsListBox.DisplayMemberPath = "Name";
}
The problem is that my ListBox have items but they are empty. Why I don't see "First1" and "First2" instead?

The issue here isn't with the bindings nor the ItemTemplate nor the change notification. It's the Anonymous Type you're using that's causing it. try using a class or struct for your items
public class Item
{
public string Name { get; set; }
}
protected override void OnNavigatedTo(NavigationEventArgs e)
{
RoomsListBox.ItemsSource = new[] {
new Item { Name = "First1" },
new Item { Name = "First2" }};
RoomsListBox.DisplayMemberPath = "Name";
}
your xaml stays the same, or you can define a DataTemplate for the ListBox items if you want. Note that you can't set both the ItemTemplate and DisplayMemberPath at the same time (one has to be null). Also, make sure that the class representing your items has to be public.
Hope this helps :)

Just a thought..
Have you tried settings the DisplayMemberPath property in XAML? There might be an issue with the order of calls.

You have to set DisplayMemberPath property on your ListBox to Name.
Moving forward you might want to consider creating a DataTemplate for your items to have more control:
<ListBox x:Name ="RoomsListBox" Height="100"
HorizontalAlignment="Left" Margin="12,41,0,0"
VerticalAlignment="Top" Width="120">
<ListBox.ItemTemplate>
<DataTemplate>
<StackPanel>
<TextBlock Text="{Binding Name}"/>
</StackPanel>
</DataTemplate>
</ListBox.ItemTemplate>
</ListBox>
See this tutorial for more info: http://weblogs.asp.net/scottgu/pages/silverlight-tutorial-part-5-using-the-listbox-and-databinding-to-display-list-data.aspx

I would prefer that you define your binding in your xaml and for example in your Code-Behind you define a property for the items of your listbox.
Example: (xaml)
<ListBox Name ="RoomsListBox"
ItemsSource="{Binding MyItems}"
Height="100"
HorizontalAlignment="Left"
Margin="12,41,0,0"
VerticalAlignment="Top"
Width="120" />
Example: (C# in your code-behind)
//...
private ObservableCollection<string> _myItems;
public ObservableCollection<String> MyItems
{
get
{
return _myItems ?? (_myItems = new ObservableCollection<string> { "FirstItem", "SecondItem"});
}
set
{
_myItems = value;
}
}
Like ChrisF said you could use the INotifiyPropertyChanged Interface, there you would raise the PropertyChanged event in the setter of your property.
See --> http://msdn.microsoft.com/en-us/library/system.componentmodel.inotifypropertychanged.aspx