We were able to understand if ItemsControl finished it's rendering by checking Status within StatusChanged event in WPF.
How can I make sure that ItemsControl finished rendering in UWP? I want to make sure that rendering is completed and access some elements using ContainerFromItem.
I have custom dragging logic using events like ManipulationDelta. After rendering, I want to get the ContentPresenter's position based on it's parent UIElement and then use that position to draw some stuff using Win2D. I need item's position, so I need the container, so I need to make sure containers are rendered in the first place, and it goes like that.
To use ItemsControl in UWP, you also need to know about the UI virtualization. The ItemsControl uses UI virtualization. It means that not all items will be rendered at the same time, instead only the viewable area.
You could try the following code:
<ItemsControl x:Name="item">
<ItemsControl.ItemTemplate>
<DataTemplate>
<Grid Loaded="Grid_Loaded">
<TextBlock Text="{Binding}"></TextBlock>
</Grid>
</DataTemplate>
</ItemsControl.ItemTemplate>
</ItemsControl>
I registered the Loaded event for the 'Grid' which is included in every item.
Related
I am trying to get a RichEditBox to take over the entire width of the app window and to be responsive to window resizing, so far the code I have is the following:
<RichEditBox HorizontalAlignment="Stretch"
TextWrapping="WrapWholeWords"
Height="250"
Name="Intro"/>
What I am getting from the code above is this:
Any ideas on how can I get this to work? Why is it that I tell the text to wrap and it doesn't follow?
UPDATE
I also tried this:
<RichEditBox HorizontalAlignment="Stretch"
Height="250"
Name="Intro"/>
But the result is:
The problem that I am having is that it seems that HorizontalAlignment="Stretch" does not really do anything. The only way I am able to set a decent width is by hard-coding it, for example: Width="600". But if I do this my UI will not respond correctly to resizing. I also tried HorizontalContentAlingment="Stretch" but the result is exactly the same.
How can I get my RichEditBox take up all the available Width and Wrap at the same time?
If you look at the documentation of RichEditBox.TextWrapping, you'll notice that WrapWholeWords is invalid. You have to use
<RichEditBox TextWrapping="Wrap"/>
-or-
<RichEditBox TextWrapping="NoWrap"/>
Since Wrap is the default value, you can drop the property.
<RichEditBox HorizontalAlignment="Stretch"
Height="250"
Name="Intro"/>
Edit: in reply to the updated question:
A control only takes the width of it's parent control. Some container controls (e.g. Grid) automatically take the full width available, while others (e.g. StackPanel) only take the required size of it's children. Using HorizontalAlignment="Stretch" in combination with a StackPanel as a parent control, will only use the MinWidth property instead of the full available width on your screen. Sometimes you can't directly see this issue, e.g. when your control is inside an itemtemplate of a ListView. Use the Live Visual Tree in Visual Studio to find the parent containers and locate the issue.
So in short: make sure your RichEditBox is inside a Grid (or similar control) instead of a StackPanel.
I'm making a Windows Store App using C# and XAML. How can I manipulate one single item in a GridView or a ListView?
According to certain logical conditions, I need to load or not the item in these containers. I have already tried using the property Visibility.Collapsed and Visibility.Visible of the item, but this just hides or shows the item and it is still loaded in the GridView/ListView, and is selectable.
Thanks for your help.
I reckon you meant to hide your GridViewItem without keeping space in view.
You just need to replace GridView's ItemsPanel with StackPanel or VirtualizingStackPanel.
<GridView>
<GridView.ItemsPanel>
<ItemsPanelTemplate>
<StackPanel />
</ItemsPanelTemplate>
</GridView.ItemsPanel>
</GridView>
I'm playing with the "Grid Application," which is a C++ Metro app template provided by VS11. The main display is a collection of items displayed in a VirtualizingStackPanel:
<ScrollViewer x:name="itemGridScrollViewer">
<GridView x:name="itemGridView">
<GridView.ItemsPanel>
<ItemsPanelTemplate>
<VirtualizingStackPanel />
</ItemsPanelTemplate>
</GridView.ItemsPanel>
</GridView>
</ScrollViewer>
The actual items are displayed using the Standard250x250ItemTemplate data template defined in StandardStyles.xaml. One of the display elements of this is a graphic.
I'm trying to understand how to reference a specific item so that I can change the graphic at runtime. The ScrollViewer and the GridView have objects associated with them, so I can get to those, but I don't see how to get from there to the individual items.
All this stuff is completely new to me, so be gentle. :)
In general it's not a good idea to dig down into individual templated items in an ItemsControl because not only is it a pain, but that ItemTemplate can regenerate at different times (paging during virtualization, source collection updates, etc) and you'll be left holding an outdated UIElement that's no longer being displayed.
A better approach is to pull the data you need into the item data and in the ItemTemplate use Data Binding to make whatever changes you need to differentiate the UI. One option is to use an IValueConverter to get a different image depending on some state in the item data:
<GridView>
<GridView.ItemTemplate>
<DataTemplate>
<Image Source="{Binding Path=DataState, Converter={StaticResource MyStateToImageConverter}}"/>
</DataTemplate>
</GridView.ItemTemplate>
</GridView>
Here I'm assuming that the converter code has been written and an instance of the converter has already been declared as a resource (see here). You could alternatively do a direct Binding to a property on each item's data that specifies its image and skip the converter part.
I have a custom WPF control to display a list of items using an ItemsControl. The ItemsPresenter is defined in the template to display the list and it is embedded inside a ScrollViewer for scrolling purposes:
<ControlTemplate TargetType="ItemsControl">
<Grid x:Name="LayoutRoot">
<ScrollViewer Margin="3">
<ItemsPresenter/>
</ScrollViewer>
</Grid>
</ControlTemplate>
My application creates two instances of the custom control to show the list side by side.
What I want is when user selects an item on the first one, the second control automatically scrolls so that the same item is displayed in the same position relative to the top. To accomplish this I need to know
How to get the position (in pixels) of the selected item in the first control?
How to scroll to the same position in the second control?
Are there any other ways to do this?
I have the following snippet:
<StackPanel>
<Popup>
<TextBox ToolTip="Edit current date"/>
</Popup>
<Label "Current Date"/>
</StackPanel>
I want the popup to show when the StackPanel is clicked, and hidden when it (the Popup) loses focus.
I was wondering what would be the shortest way to write this in xaml.
To do this with an animation, use BooleanAnimationUsingKeyFrames. The example shows how to animate the IsEnabled property but will work equally well with Popup.IsOpen. (You'll need to scroll waaaay down to see the XAML example.) Take care about the FillBehavior so that the Popup doesn't animate back to being closed when the animation ends (unless of course this is what you want!).