How create own animation when item add or remove from GridView? For example change colour from dark to light.
If Item is a Grid:
<Grid.Transitions>
--> There can be only predefinied *ThemeTransitions?
</Grid.Transitions>
Is other way to do this?
Tim is correct that the Transitions are pre-defined at this point. However, you should be able to achieve your scenario using Storyboard. There are probably several ways to do this, e.g. retemplating GridViewItem and adding new "Loading"/"Unloading" visual states. Here is a simple way to achieve your scenario by putting a Storyboard in the ItemTemplate:
MainPage.xaml:
<GridView x:Name="MyGV">
<GridView.ItemTemplate>
<DataTemplate>
<Grid Loaded="Grid_Loaded" x:Name="TemplateRoot" Opacity="0" Background="White">
<Grid.Resources>
<Storyboard x:Key="LoadedStoryboard">
<DoubleAnimation Storyboard.TargetName="TemplateRoot"
Storyboard.TargetProperty="Opacity"
BeginTime="0:0:1"
Duration="0:0:5"
To="1" />
</Storyboard>
</Grid.Resources>
<TextBlock Text="{Binding}" FontSize="24" Foreground="Black" Margin="40" />
</Grid>
</DataTemplate>
</GridView.ItemTemplate>
</GridView>
MainPage.xaml.cs:
private void Grid_Loaded(object sender, RoutedEventArgs e)
{
Storyboard sb = ((Grid)sender).Resources["LoadedStoryboard"] as Storyboard;
sb.Begin();
}
Example source code is hosted here:
https://github.com/finnigantime/Samples/tree/master/examples/Win8Xaml/GridViewItemLoadedUnloadedAnimations
What if the set that is used as the GridView's ItemsSource was an ObservableCollection and your code behind listened for changes from that collection? Then from the code behind you could control animations.
Correct, there can only be pre-defined transitions. The transition model is not exposed publically at this time.
The rows added to the "parent" ListView of a GridView could be fed in several ways, but often are bound to a ObservableCollection of something.
The columns of the GridView are governed with a ObservableCollection, as well, so the context should be pretty similar.
I published an article on how to manage the columns' management (with animation) just some days ago. Perhaps could help you.
http://highfieldtales.wordpress.com/2013/08/08/hacking-the-wpf-gridview-adding-the-animation/
UPDATE: pardon me, but I realized later that you meant the XAML for Store apps. My reference is for WPF, instead.
Related
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.
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.
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.
I'm using a ListBox with its DataTemplate containing a Canvas. I then bind the Left/Top of the Grid containing that Canvas to move it to a certain point.
I want to then have the child Grid centred at the X,Y coordinates I've specified, where the size of the child Grid is variable based on its content. I was planning on achieving this by using a TranslateTransform to move the Grid by half of its width.
I can't see how I can set that TranslateTransform however as ElementName binding doesn't work within a DataTemplate. Any ideas how I can achieve this?
<ItemsControl ItemsSource="{TemplateBinding SomeCollection}">
<ItemsControl.ItemsPanel>
<ItemsPanelTemplate>
<Grid HorizontalAlignment="Stretch" VerticalAlignment="Stretch" />
</ItemsPanelTemplate>
</ItemsControl.ItemsPanel>
<ItemsControl.ItemTemplate>
<DataTemplate>
<Canvas>
<Grid x:Name="Container"
Canvas.Left="{Binding X}"
Canvas.Top="{Binding Y}"
Background="#88000000">
<Grid.RenderTransform>
<TranslateTransform X="{Binding ActualWidth, ElementName=Container, Converter={StaticResource NegativeHalfConverter}}"
Y="{Binding ActualHeight, ElementName=Container, Converter={StaticResource NegativeHalfConverter}}" />
</Grid.RenderTransform>
<TextBlock Text="{Binding SomeValue}" FontSize="36" Foreground="White" />
</Grid>
</Canvas>
</DataTemplate>
</ItemsControl.ItemTemplate>
`
I think ElementName binding should work in the name scope of a DataTemplate, but I have seen people complaining about bindings not updating correctly when binding to ActualWidth/Height properties. Perhaps instead of doing the complicated setup you have you could just implement an attached behavior that takes a Point parameter and updates the Canvas.Left/Top properties whenever the parameter or size of the associated object (your grid) changes.
Looks like the fault wasn't with the binding itself, but with a feature that means the ActualWidth/ActualHeight properties aren't bindable. Thanks Filip.
To fix this I created a derived Grid with a couple of new dependency properties that I update in the SizeChanged events to have the ActualWidth/Height. I then use my DataTemplate as above, binding to these new DPs to translate and centre my Grid on a point. Seems to work a treat.
To move an object by half of its size you can use 2 rotations or scales: first is over 0.25,0.25 relative point, second is over the enter point 0.5,0.5. If you use rotations then angels are 180 degrees and -180 degrees. If you use scales then scale factors are -1,-1 and -1,-1.
Do not forget about RenderTransformOrigin property. And to apply two transforms you can apply them to two nested elements.
I have a windows phone 7 app with some xaml that looks like:
<Grid x:Name="ContentGrid" Grid.Row="1">
<ItemsControl x:Name="MyView" ItemTemplate="{StaticResource MyInner}"/>
</Grid>
The item template here looks like:
<DataTemplate x:Key="MyInner">
<ItemsControl ItemsSource="{Binding}" ItemTemplate="{StaticResource MyInner_Item}">
<ItemsControl.ItemsPanel>
<ItemsPanelTemplate>
<StackPanel Orientation="Horizontal"/>
</ItemsPanelTemplate>
</ItemsControl.ItemsPanel>
</ItemsControl>
</DataTemplate>
And finally, the MyInner_Item template looks like:
<DataTemplate x:Key="MyInner_Item">
<Button x:Name="MyButton">
<Button.Template>
<ControlTemplate>
<Border HorizontalAlignment="Center" VerticalAlignment="Center" x:Name="myborder">
<Image Source="{Binding Path=ImageUri}" Width="{Binding Path=Width}" Height="{Binding Path=Height}" Stretch="Fill" />
</Border>
</ControlTemplate>
</Button.Template>
</Button>
</DataTemplate>
So, it's an ItemsControl, which contains an ItemsControl, which contains buttons. This essentially creates a 2D array of buttons.
What I want to do is add an event handler to the Click event of the buttons.
Here's the catch: the code that sits behind this is written in F#. I can't, to the best of my knowledge, specify my event handler in the XAML, as F# doesn't talk to WPF in any nice way. So I need to add my event handler(s) manually in code.
Is there an easy way of doing this?
Currently, I have some F# which looks like:
let myView : ItemsControl = this?MyView
do myView.ItemsSource <- viewModel.BoardData
Here, the BoardData is a list of lists.
I was wondering if it's possible to loop through the controls in the ItemsControl, to add my event handlers? I'm having a bit of trouble doing this though. For example, in the following:
let container = myView.ItemContainerGenerator.ContainerFromItem(myView.Items.[0])
...sets container to null. In fact, all the methods I've tried from myView.ItemContainerGenerator returns null.
So, how should I go about attaching my event handler, so that I can respond to the buttons being clicked?
I have not done any Windows 7 Phone development, but I have done plenty of XAML + Silverlight development with C# and now I'm getting into doing some F# development. The approach I would take is by not using event handler's at all. Since you are using a button, make a class that derives from ICommand and add that type as a public property on your ViewModel so you could bind it to the Command property of the button. The benefits of using the ICommand interface over event handlers is that you could also have a condition on when the button is enabled to do the action.
Also, take notice that when you are doing binding expressions within (i.e. ItemTemplate) items in an ItemsControl control, the scope of what properties you can bind to are reduced to the properties of the current item. So all of the properties of the ViewModel are out of scope, unless you specify it fully i.e. <Button Command={Binding Source=ViewModel, Path=Property1.Property2.etc} />. Let me know if this helped.