I have UWP page and it is using data binding to set content on xaml elements (texts, buttons, image). I am setting the content using async calls (getting content from internet). In the page's c'tor, I subscribed to Loaded event. And obtained button using FindName() method on the control. Got the content on the button and it is coming as empty. I am assuming it is because I am setting content using async calls and when I debugged using breakpoints, it is indeed the case. The content is set after Loaded event is fired.
So my question is - what is the event fired when content on xaml elements becomes available?
Below is my code:
void ValuePropControl::ControlLoaded(Windows::Foundation::IInspectable const& sender, Windows::UI::Xaml::RoutedEventArgs const& e)
{
auto b{ sender.as<ValueProp::ValuePropControl>() };
auto buttttton = b.FindName(L"OpenFamilyAppButton");
auto bbttnn = buttttton.as<Windows::UI::Xaml::Controls::Button>();
auto contentt = bbttnn.Content();
auto texxxt = winrt::unbox_value<hstring>(contentt);
}
Variable 'texxxt' is empty.
<Grid
Grid.Column="0"
CornerRadius="3">
<Button
x:Name="OpenFamilyAppButton"
MinWidth="118"
MinHeight="30"
HorizontalAlignment="Left"
HorizontalContentAlignment="Center"
VerticalContentAlignment="Center"
AutomationProperties.Name="{x:Bind ViewModel.PrimaryActionAutomationName, Mode=OneWay}"
BorderThickness="1"
Click="{x:Bind ViewModel.InvokePrimaryAction}"
Content="{x:Bind ViewModel.PrimaryAction, Mode=OneWay}"
CornerRadius="3"
Style="{StaticResource AccentButtonStyle}" />
</Grid>
Related
I have a Popup which will fill the whole page when opened.
<Grid x:Name="gridRoot" Background="{ThemeResource ApplicationPageBackgroundThemeBrush}">
<Button Content="Open" HorizontalAlignment="Center" Click="{x:Bind viewModel.OpenPopup}" />
<Popup x:Name="popupCorrect" VerticalAlignment="Top" IsOpen="{Binding IsOpen}" IsLightDismissEnabled="False">
<Popup.ChildTransitions>
<TransitionCollection>
<PaneThemeTransition Edge="Left" />
</TransitionCollection>
</Popup.ChildTransitions>
<uc:MyPopup Width="{Binding ElementName=gridRoot, Path=ActualWidth}" Height="{Binding ElementName=gridRoot, Path=ActualHeight}"/>
</Popup>
</Grid>
The Popup is a UserControl
<Grid Background="Red">
<Button Content="Close" HorizontalAlignment="Center" Click="{x:Bind viewModel.ClosePopup}" />
</Grid>
The page
When popup is shown
Close the popup, resize the page, then reopen the popup. Notice that it does not match the new size of container page even though its Width and Height is bound to gridRoot . Do I have to manually set a new Width and Height for the popup? Why can't I achieve this with binding? This issue also appears on mobile during 'OrientationChanged'
Based on Decade Moon comment, this is how to resize the popup to match the parent container as its size changed.
Create a dependency property in the code behind
public double PageWidth
{
get { return (double)GetValue(PageWidthProperty); }
set { SetValue(PageWidthProperty, value); }
}
public static readonly DependencyProperty PageWidthProperty =
DependencyProperty.Register("PageWidth", typeof(double), typeof(GamePage), new PropertyMetadata(0d));
public double PageHeight
{
get { return (double)GetValue(PageHeightProperty); }
set { SetValue(PageHeightProperty, value); }
}
public static readonly DependencyProperty PageHeightProperty =
DependencyProperty.Register("PageHeight", typeof(double), typeof(GamePage), new PropertyMetadata(0d));
Update the value on SizeChanged event
private void GamePage_SizeChanged(object sender, SizeChangedEventArgs e)
{
if (e.NewSize.Width > 0d && e.NewSize.Height > 0d)
{
PageWidth = e.NewSize.Width;
PageHeight = e.NewSize.Height;
}
}
Then in XAML, just use x:Bind to bind the popup width and height
<Popup x:Name="popupCorrect" VerticalAlignment="Top" IsOpen="{Binding IsPopupCorrectOpen, Mode=TwoWay}" IsLightDismissEnabled="False">
<Popup.ChildTransitions>
<TransitionCollection>
<PaneThemeTransition Edge="Left" />
</TransitionCollection>
</Popup.ChildTransitions>
<uc:PopupCorrect Width="{x:Bind PageWidth, Mode=TwoWay}" Height="{x:Bind PageHeight, Mode=TwoWay}"/>
</Popup>
Pretty straight forward. Just remember not to use the ActualWidth or ActualHeight properties for binding source as they do not raise the PropertyChanged event.
Although it has an ActualWidthProperty backing field, ActualWidth does not raise property change notifications and it should be thought of as a regular CLR property and not a dependency property.
For purposes of ElementName binding, ActualWidth does not post updates when it changes (due to its asynchronous and run-time calculated nature). Do not attempt to use ActualWidth as a binding source for an ElementName binding. If you have a scenario that requires updates based on ActualWidth, use a SizeChanged handler.
#PutraKg have a great way.
But I have two way to solve it.
The first is set the VerticalAlignment="Center" HorizontalAlignment="Center" that can make the popup in the center.
But I think youare not content to put it in the center.
The great way is use the screen position.
You can get the Grid's screen postion and make it to popup.
In open button
private void Button_OnClick(object sender, RoutedEventArgs e)
{
var grid = (UIElement)popupCorrect.Parent; //get grid
var p = grid.TransformToVisual (Window.Current.Content).TransformPoint(new Point(0, 0)); //get point
popupCorrect.HorizontalOffset = p.X;
popupCorrect.VerticalOffset = p.Y;
popupCorrect.IsOpen = !popupCorrect.IsOpen;
}
I'm building a Windows Phone 8.1 Hub Application. One of the hub section contains a ListView that displays a list of articles. I'd like to add a Textblock to this hubsection which displays a message when the articles failed to download. The XAML Code is below:
<HubSection
x:Uid="ArticlesSection"
Header="ARTICLES"
DataContext="{Binding Articles}"
HeaderTemplate="{ThemeResource HubSectionHeaderTemplate}">
<DataTemplate>
<Grid>
<ListView
AutomationProperties.AutomationId="ItemListViewSection3"
AutomationProperties.Name="Items In Group"
SelectionMode="None"
IsItemClickEnabled="True"
ItemsSource="{Binding}"
ItemTemplate="{StaticResource BannerBackgroundArticleTemplate}"
ItemClick="ItemView_ItemClick"
ContinuumNavigationTransitionInfo.ExitElementContainer="True">
</ListView>
<TextBlock
x:Name="NoArticlesTextBlock"
HorizontalAlignment="Center"
VerticalAlignment="center"
Style="{StaticResource HeaderTextBlockStyle}"
TextWrapping="WrapWholeWords"
TextAlignment="Center"/>
</Grid>
</DataTemplate>
</HubSection>
The problem I'm having is that I can't access the TextBlock from the C# code. Is there an easier way to do this?
The problem I'm having is that I can't access the TextBlock from the C# code.
Yes, since the TextBlock is defined inside a DataTemplate, the TextBlock won't be available until the DataTemplate has been applied. Thus, the x:Name attribute won't automatically generate a variable reference in the InitializeComponent method in your *.g.i.cs file. (Read up on XAML Namescopes for more information).
If you want to access it from your code-behind, there are two ways:
The first way is the simplest: you can get a reference to the TextBlock in the sender argument of the Loaded event handler for that TextBlock.
<TextBlock Loaded="NoArticlesTextBlock_Loaded" />
Then in your code-behind:
private TextBlock NoArticlesTextBlock;
private void NoArticlesTextBlock_Loaded(object sender, RoutedEventArgs e)
{
NoArticlesTextBlock = (TextBlock)sender;
}
The second way is to traverse the visual tree manually to locate the element with the required name. This is more suitable for dynamic layouts, or when you have a lot of controls you want to reference that doing the previous way would be too messy. You can achieve it like this:
<Page Loaded="Page_Loaded" ... />
Then in your code-behind:
static DependencyObject FindChildByName(DependencyObject from, string name)
{
int count = VisualTreeHelper.GetChildrenCount(from);
for (int i = 0; i < count; i++)
{
var child = VisualTreeHelper.GetChild(from, i);
if (child is FrameworkElement && ((FrameworkElement)child).Name == name)
return child;
var result = FindChildByName(child, name);
if (result != null)
return result;
}
return null;
}
private TextBlock NoArticlesTextBlock;
private void Page_Loaded(object sender, RoutedEventArgs e)
{
// Note: No need to start searching from the root (this), we can just start
// from the relevant HubSection or whatever. Make sure your TextBlock has
// x:Name="NoArticlesTextBlock" attribute in the XAML.
NoArticlesTextBlock = (TextBlock)FindChildByName(this, "NoArticlesTextBlock");
}
Jerry Nixon has a good page on his blog about this.
I'm using Bing Maps in my Windows Store app, I display some pushpins with some locations on it.
What I want to do is when the user taps on a pushpin, a popup appears with some info related to the location of that push pin. something similar to the popup when the user taps on my location in Microsoft maps application
How can this be done ?
Very easy, you can use the Tapped event of your Pushpin to trigger a popup then use a MapLayer.SetPosition to position your popup see http://msdn.microsoft.com/en-us/library/hh846488.aspx
Like this
currentLocationPushpin.Tapped += Current_location_pushpin_tapped;
then
void Current_location_pushpin_tapped(object sender, TappedRoutedEventArgs e)
{
MapLayer.SetPosition(placesAroundYou,location);
MapLayer.SetPositionAnchor(placesAroundYou, new Point(-200, 40));
BingMap.Children.Add(_mapLayer);
}
Try using a Popup control or fake one like this
You can either use a Popup control (see MSDN documentation here) or toggle visibility of a Border element to fake a Popup using Visibility="Collapsed", try this
<Border Background="#FFC3C2BF" Opacity="50" Margin="38,0,0,376" BorderThickness="1" BorderBrush="Black" CornerRadius="8" HorizontalAlignment="Left" MinWidth="50" Width="126" Height="auto">
<TextBlock x:Name="PushpinText" HorizontalAlignment="Left" TextWrapping="Wrap" VerticalAlignment="Top" Foreground="Black" Padding="10,10,10,10" />
</Border>
I want to implement auto-complete on a textbox in a Windows 8 UI / Metro UI app using C#/XAML.
At the moment, when the soft / touch keyboard shows, it obscures the auto-complete box. However, on the text box focus, Windows 8 automatically scrolls the entire view up and ensures the text box is in focus.
In reality, all I want is the view to scroll up a little more (in fact, by the height of the auto-complete box).
I realise I can intercept the Showing event of InputPane.GetForCurrentView()
I can set InputPaneVisibilityEventArgs.EnsuredFocusedElementInView to true inside the Showing event fine (so Windows won't try to do anything).... however, how can I invoke the same scrolling functionality that Windows 8 would do, but ask it to scroll a little more!?
Here's the code for the main page:
<Grid Background="{StaticResource ApplicationPageBackgroundThemeBrush}">
<StackPanel VerticalAlignment="Center" HorizontalAlignment="Center" Margin="0,200,0,0">
<TextBlock HorizontalAlignment="Center" FontSize="60">App 1</TextBlock>
<TextBlock HorizontalAlignment="Center">Enter text below</TextBlock>
<TextBox HorizontalAlignment="Center" Margin="-10,0,10,0" Width="400" Height="30"/>
<ListBox HorizontalAlignment="Center" Width="400">
<ListBoxItem>Auto complete item 1</ListBoxItem>
<ListBoxItem>Auto complete item 2</ListBoxItem>
<ListBoxItem>Auto complete item 3</ListBoxItem>
<ListBoxItem>Auto complete item 4</ListBoxItem>
<ListBoxItem>Auto complete item 5</ListBoxItem>
</ListBox>
</StackPanel>
</Grid>
If you start up the simulator with the lowest resolution, use the hand to "touch" the textbox, this will bring up the soft keyboard. In the real app, the auto complete list will appear with items as the user enters text.
So in a nutshell, how can I move the screen up a bit more so the user can see the entire autocomplete list?
Bear in mind, in the real app, it'll be worse, as the user may not even notice the autocomplete list appearing "underneath" the keyboard.
I really would appreciate some advice, many thanks!
I have created an AutoCompleteBox for Windows Store apps, the nuget package is available at https://nuget.org/packages/AutoCompleteBoxWinRT
Ok, here is how I would tackle this since I cannot seem to find any way to control the scrolling of the app based on the appearance of the keyboard. I would create a user control that would form the basis for the auto-complete textbox.
<UserControl
x:Class="App6.MyUserControl1"
xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
xmlns:local="using:App6"
xmlns:d="http://schemas.microsoft.com/expression/blend/2008"
xmlns:mc="http://schemas.openxmlformats.org/markup-compatibility/2006"
mc:Ignorable="d"
d:DesignHeight="300"
d:DesignWidth="400">
<Grid>
<TextBox x:Name="textBox" TextWrapping="Wrap" Text="TextBox" VerticalAlignment="Top" GotFocus="textBox_GotFocus" LostFocus="textBox_LostFocus" />
<ListBox x:Name="listBox" Height="150" Margin="0,-150,0,0" VerticalAlignment="Top" Visibility="Collapsed"/>
</Grid>
This is an incredibly basic implementation, so you will have to tweak to meet your needs.
Then, I would add the following code-behind to the user control
public sealed partial class MyUserControl1 : UserControl
{
// Rect occludedRect;
bool hasFocus = false;
public MyUserControl1()
{
this.InitializeComponent();
InputPane.GetForCurrentView().Showing += MyUserControl1_Showing;
}
void MyUserControl1_Showing(InputPane sender, InputPaneVisibilityEventArgs args)
{
if (hasFocus)
{
var occludedRect = args.OccludedRect;
var element = textBox.TransformToVisual(null);
var point = element.TransformPoint(new Point(0, 0));
if (occludedRect.Top < point.Y + textBox.ActualHeight + listBox.ActualHeight)
{
listBox.Margin = new Thickness(0, -listBox.ActualHeight, 0, 0); // Draw above
}
else
{
listBox.Margin = new Thickness(0, textBox.ActualHeight, 0, 0); // draw below
}
}
}
private void textBox_GotFocus(object sender, RoutedEventArgs e)
{
listBox.Visibility = Windows.UI.Xaml.Visibility.Visible;
hasFocus = true;
}
private void textBox_LostFocus(object sender, RoutedEventArgs e)
{
listBox.Visibility = Windows.UI.Xaml.Visibility.Collapsed;
hasFocus = false;
}
}
Next steps would be to expose properties to pass data to be bound to the ListBox. Hard core would be ListBoxItem templating and more, depending on how reusable you wanted it to be.
My question is the following:
I have a grid and I attached the SelectedIndexChanged event the following way in the xaml file:
"<cc:DetailViewGrid AutoGenerateColumns="False" HorizontalAlignment="Stretch" Margin="0,0,0,0" Name="dgAcitivityList" VerticalAlignment="Stretch" ItemsSource="{Binding EntityList}" SelectionMode="Single" IsReadOnly="False">
<interactivity:Interaction.Triggers>
<interactivity:EventTrigger EventName="SelectionChanged">
<interactivity:InvokeCommandAction Command="{Binding SelectedItemChangeCommand}" CommandParameter="{Binding SelectedItem, ElementName=dgAcitivityList}"/>
</interactivity:EventTrigger>
</interactivity:Interaction.Triggers>"
But I want to attach this event in code behind. I ctreated an own grid that is inherited from windows grid, and I put this code to own control.
public override void OnApplyTemplate()
{
//base.OnApplyTemplate();
System.Windows.Interactivity.EventTrigger selectedItemChangedTrigger = new System.Windows.Interactivity.EventTrigger("SelectionChanged");
System.Windows.Interactivity.InvokeCommandAction action = new System.Windows.Interactivity.InvokeCommandAction();
action.CommandName = "{Binding SelectedItemChangeCommand}";
action.CommandParameter = string.Format("{{Binding SelectedItem, ElementName={0}}}", this.Name);
selectedItemChangedTrigger.Actions.Add(action);
System.Windows.Interactivity.Interaction.GetTriggers(this).Add(selectedItemChangedTrigger);
base.OnApplyTemplate();
}
Is this solution proper? It's not working but I'm not sure that I should put this code in the OnApplyTemplate() method.