What is the equivalent to MenuItemSource in WinUI 3 NavigationView - xaml

I'm trying to bind to the NavigationView using the MenuItemSource property, but apparently, that property has gone away in WinUI 3. I searched the documentation, but it seems to only go to 2.8: https://learn.microsoft.com/en-us/windows/winui/api/microsoft.ui.xaml.controls.navigationview?view=winui-2.8
My navigation view looks like this.
<NavigationView x:Name="NavView"
Loaded="NavView_Loaded"
ItemInvoked="NavView_ItemInvoked"
BackRequested="NavView_BackRequested"
Grid.Column="0"
MenuItemSource = "{x:Bind Categories, Mode=OneWay}">
<NavigationView.AutoSuggestBox>
<!-- See AutoSuggestBox documentation for
more info about how to implement search. -->
<AutoSuggestBox x:Name="NavViewSearchBox" QueryIcon="Find"/>
</NavigationView.AutoSuggestBox>
<ScrollViewer>
<Frame x:Name="ContentFrame" Padding="12,0,12,24" IsTabStop="True"
NavigationFailed="ContentFrame_NavigationFailed"/>
</ScrollViewer>
</NavigationView>
The MenuItemSource throws:
The property 'MenuItemSource' was not found in type 'NavigationView'
How can I bind an ObservableCollection to the NavigationView in WinUi 3?

Related

How to change the tab index in avalonia ui

In Avalonia Ui,
I have multiple layouts in my ui and I want a very specific tab order,
something like
<TextBox Tabindex="2">
<StackPanel>
<TextBox Tabindex="1">
</StackPanel>
<TextBox Tabindex="0">
that would result in using the tab-key cycling from bottom to top.
Is this possible? I found nothing.
I don't think so. KeyboardNavigation.TabIndex is not implmented yet: https://github.com/AvaloniaUI/Avalonia/issues/3025.
You have some limited Control using the functions provided in KeyboardNavigation and by using another control, for example a DockPanel or a Relative Panel.
Here is a very basic example for how you can use a DockPanel to do what you wish to:
<DockPanel LastChildFill="False"
VerticalAlignment="Top"
Name="TabOrderConatiner">
<TextBox Name="First" Tag="2" DockPanel.Dock="Top"></TextBox>
<TextBox Name="Third" Tag="0" DockPanel.Dock="Bottom"></TextBox>
<TextBox Name="Second" Tag="1" DockPanel.Dock="Top"></TextBox>
</DockPanel>
However it is like I said above limited compared to what TabIndex can provide.
Apart from that you should also be able to set the first TabItem when the container becomes active like that from your code-behind:
var tabOrderContainer = this.FindControl<DockPanel>("TabOrderConatiner");
var initialElement = this.FindControl<TextBox>("Third");
KeyboardNavigation.SetTabOnceActiveElement(tabOrderContainer, initialElement);
but I did not manage to get this to work...

Using x:Bind inside the GridView's ItemTemplate layout User Control in UWP

In the Universal Windows Platform API, how do I use x:Bind inside of a User Control (intended to be the layout for a GridView's ItemTemplate) to bind to instance properties of a GridView's ItemSource?
Background
I'm trying to re-create the layout found in Windows 10 stock apps like Sports, News, Money, etc.
I'm using a two GridViews for the main area of the app; one for "featured articles" (2 large photos w/ headlines) and one for all the other articles (smaller photos w/ headlines).
I'm able to bind to a data source that I supply in the code behind (a List where NewsItem is a POCO with a Image and Headline property) Here's the pertinent parts of the MainPage.xaml:
<Page ...
xmlns:data="using:NewsApp.Models" />
....
<GridView Name="FeaturedItems" Grid.Row="0">
<GridView.ItemTemplate>
<DataTemplate x:DataType="data:NewsItem">
<Grid Name="mainPanel" HorizontalAlignment="Stretch" Width="500" >
<Image Source="{x:Bind Image}" HorizontalAlignment="Stretch" />
<TextBlock Text="{x:Bind Headline}" />
</Grid>
</DataTemplate>
</GridView.ItemTemplate>
</GridView>
....
The Image and Headline bind just fine (even though they've not been styled correctly). However, instead I think I need to bind to a User Control to get the styling options I want, control over resizing esp. when using Visual State Triggers and to simplify the XAML in general (at least, this was the technique suggested to me.)
So, I added a new User Control to the project (FeaturedItemControl.xaml), and copied in the DataTemplate's child Grid:
<UserControl ... >
<Grid Name="mainPanel" HorizontalAlignment="Stretch" Width="500" >
<Image Source="{x:Bind Image}" HorizontalAlignment="Stretch" />
<TextBlock Text="{x:Bind Headline}" />
</Grid>
</UserControl>
And then back in the MainPage.xaml, I change the DataTemplate to reference the new FeaturedItemControl:
<GridView Name="FeaturedItems" Grid.Row="0">
<GridView.ItemTemplate>
<DataTemplate x:DataType="data:NewsItem">
<local:FeaturedItemControl HorizontalAlignment="Stretch" VerticalAlignment="Stretch" />
</DataTemplate>
</GridView.ItemTemplate>
</GridView>
However, I get the error message for both Image and Headline properties: Invalid binding path 'Headline': Property 'Headline' can't be found on type 'FeaturedItemControl'.
I've tried a few things but am flailing just throwing code at the problem without understanding what I'm doing. Any help would be greatly appreciated.
Thank you for your kind attention.
Using Depechie's answer, I formulated this little cheat cheat for posterity:
Do note that you MUST use this technique to utilize the VisualStateManager with items inside your data bound controls' (GridView, ListView) data templates.
1) Create a User Control.
2) Cut the content of the DataTemplate in your page and paste it into the User Control replacing the template's Grid.
3) Reference the User Control from inside the Data Template:
4) Modify the contents of the User Control changing x:Bind statements to utilize object.property notation:
<UserControl>
<StackPanel>
<Image Source="{x:Bind NewsItem.LeadPhoto}" />
<TextBlock Text="{x:Bind NewsItem.Headline}" />
<TextBlock Text="{x:Bind NewsItem.Subhead}" />
</StackPanel>
</UserControl>
5) Add this in the User Control's Code Behind:
public Models.NewsItem NewsItem { get { return this.DataContext as Models.NewsItem; } }
public ContactTemplate()
{
this.InitializeComponent();
this.DataContextChanged += (s, e) => Bindings.Update();
}
Well it's possible to use x:Bind in user controls, but you'll need to add some extra code behind.
I encountered the same problem in my project, you can see the result here : https://github.com/AppCreativity/Kliva/tree/master/src/Kliva/Controls
So what you need to do is, create a property in the code behind of your user control that points to the correct DataContext.
If you do that, you can use properties of that DataContext in the xaml of your control: for example:
Do note that in the constructor of your control you do need to add: DataContextChanged += (sender, args) => this.Bindings.Update(); because the datacontext will change depending on the page where your control is used!
Then on the page where you are placing this control, you'll also need to do the same to enable the x:bind to work.
You'll see this in my example on the MainPage.DeviceFamily-Mobile.xaml and MainPage.xaml.cs files.
Hope this helps.
x:Bind isn't really hierarchical like Binding/DataContext is. Additionally when you're not directly inside a DataTemplate (such as inside your user control) the object that x:Bind tries to use is 'this' rather than 'this.DataContext'. My current line of thinking on how to solve this sort of issue is to try not to use UserControls anywhere. Instead preferring DataTemplates contained within a ResourceDictionary. There are some pretty strong caveats to this approach though, you will for example crash the xaml compiler if you use x:Bind inside a data template that was created from the ResourceDictionary item template (add new item). you can find a pretty complete example here https://github.com/Microsoft/Windows-universal-samples/tree/master/Samples/XamlBind its important to note in the sample where they show the ResourceDictionary being used that its not actually just a ResourceDictionary.xaml its also a ResourceDictionary.xaml.cs (this is where the generated code from x:Bind ends up)
Another option is to add Headline and Image as properties on your user control and x:Bind them from the template, then inside the user control x:Bind as you are currently doing, but now the x:Bind generated path 'this.Headline' will exist. Unfortunately the order things are actually bound means that the x:Bind's you have inside your user control will have to be OneWay rather than the default OneTime. this is because x:Bind OneTime does the bind inside the InitializeComponent call, and any set of properties/DataContext stuff doesn't get done until after that has already run.
So to sum this up, you have two options, use data templates everywhere, or bind to properties that are directly on the user control.

UAP xaml triggers/data-triggers

I am trying to design a simple tabbed app using universal windows platform (UWP) using Pivot control.
I have customized header that includes other controls than just a textblock. I am targeting to change color of those controls/graphics on selection of particular PivotItem using triggers in xaml. Default color updates on selection & hover only apply on textblock but not on other controls.
I can try binding color of other controls with forecolor of textblock because I cannot find template binding not control template in UWP xaml. binding with textblock will still give less space for customization as I am targeting AccentColor for header controls/graphics which are defined by MSFT in UAP sdk and we can access them as static resource from generic.xaml. e.g. SystemControlBackgroundAccentBrush. I looked in to xaml triggers as MSFT new xaml architecture allows us to define VisualStateGroups and work using AdaptiveTriggers & StateTrigger. I can't find any other type of triggers like datatriggers, eventtriggers nothing...
<PivotItem>
<PivotItem.Header>
<StackPanel Orientation="Horizontal">
<Path Stretch="Uniform"
Fill="{StaticResource PivotForegroundThemeBrush}"
Width="32pt"
Height="32pt"
Data="M0,33.893959L4.4794149,33.893959 4.4794149,44.677959 48.903614,44.677959 48.903614,33.893959 53.333035,33.893959 53.333035,49.104958 0,49.104958z M24.842734,0L28.513577,0 28.513577,24.615005 35.345016,17.78297 40.346104,17.78297 40.436089,17.883007 26.673088,31.644001 24.072548,29.047991 12.910089,17.883007 13.010208,17.78297 18.001283,17.78297 24.842734,24.615005z"/>
<TextBlock Text="Downloads"
VerticalAlignment="Center" Margin="5"
FontSize="{StaticResource PivotHeaderItemFontSize}"/>
</StackPanel>
</PivotItem.Header>
<Grid></Grid>
</PivotItem>

{Binding ElementName=...} does not work from any CompositeTransform property

I have the following code in which I hide a WebView just under the main Grid (LayoutRoot) so I can do a sliding animation later:
<Page...>
<Grid x:Name="LayoutRoot">
...
<Grid x:Name="ContentRoot">
...
</Grid>
<WebView...>
<WebView.RenderTransform>
<CompositeTransform TranslateY="{Binding ElementName=LayoutRoot,
Path=ActualHeight}"/> <!--Does not work-->
</WebView.RenderTransform>
</WebView>
</Grid>
</Page>
When I first type the {Binding ElementName=...} line into the designer, the WebView appears just below the Grid like it should. However, when I rebuild the solution or run the app, the WebView simply obscures the whole LayoutRoot.
This will happen regardless of what I am binding to/whatever the control is; however, binding to the exact same expression will show up properly in the designer and in the phone. To demonstrate what I am saying:
<Button Width="{Binding ElementName=LayoutRoot, Path=ActualHeight}"> <!--Works perfectly, both on designer and phone-->
<Button.RenderTransform>
<CompositeTransform SomeProperty={Binding ElementName=SomeElement, Path=SomePath}"/> <!--This does not work-->
</Button.RenderTransform>
</Button>
Is there any way to bind to LayoutRoot.ActualHeight short of writing C# code for this?
One problem you have is you are trying to bind to ActualHeight which is not a dependency property nor an observable (INotifyPropertyChanged) property, so the binding is only evaluated once when it's first created.

Show DevExpress DXTabControl tabs at the bottom in XAML

Does anyone know how to use the DevExpress DXTabControl in XAML and set it up so that the tabs appear at the bottom? Here is what I have so far but the tabs show up at the top. The DevExpress documentation does not have an example of this. Intellisense does not give me anything intuitive.
<dx:DXTabControl>
<dx:DXTabItem Header="Main">
<dxdo:DockLayoutManager>
<dxdo:LayoutGroup>
<dxdo:LayoutPanel Caption="TaskList">
<views:DxTaskList x:Name="Tasklst" />
</dxdo:LayoutPanel>
<dxdo:LayoutPanel Caption="TaskDetails">
<ScrollViewer VerticalScrollBarVisibility="Auto" HorizontalScrollBarVisibility="Auto" Focusable="False">
<StackPanel>
<views:TaskDetails x:Name="TaskDtls"/>
</StackPanel>
</ScrollViewer>
</dxdo:LayoutPanel>
</dxdo:LayoutGroup>
</dxdo:DockLayoutManager>
</dx:DXTabItem>
</dx:DXTabControl>
For anyone who might be stumped at something not-so-obvious, here is the XAML solution I was looking for. Yes, the property was obviously called HeaderLocation but DevExpress' documentation does not give any XAML examples on this. So here is what I came up with that solved my case:
<dx:DXTabControl>
<dx:DXTabControl.View>
<dx:TabControlMultiLineView HeaderLocation="Bottom"/>
</dx:DXTabControl.View>
<dx:DXTabItem Header="Main">
<dxdo:DockLayoutManager>
<dxdo:LayoutGroup>
<dxdo:LayoutPanel Caption="TaskList">
<views:DxTaskList x:Name="Tasklst" />
</dxdo:LayoutPanel>
<dxdo:LayoutPanel Caption="TaskDetails">
<ScrollViewer VerticalScrollBarVisibility="Auto" HorizontalScrollBarVisibility="Auto" Focusable="False">
<StackPanel>
<views:TaskDetails x:Name="TaskDtls"/>
</StackPanel>
</ScrollViewer>
</dxdo:LayoutPanel>
</dxdo:LayoutGroup>
</dxdo:DockLayoutManager>
</dx:DXTabItem>
</dx:DXTabControl>
As you can see you're supposed to add the View property and then assign it a value, which I used a TabControlMultiLineView, and that object had a HeaderLocation property to which I set it to one of the valid enums. When I did this, the tabs appeared at the bottom.