I have a little question.
I have a data template like that :
<phone:PhoneApplicationPage.Resources>
<DataTemplate x:Key="DangersItemTemplate">
<Grid Height="102" Width="447" Tap="Grid_Tap">
<Image Name="image" Source="{Binding Image}" HorizontalAlignment="Left" Width="90" />
<TextBlock Name="text" Text="{Binding Nom}" TextWrapping="Wrap" Margin="102,16,16,22"/>
</Grid>
</DataTemplate>
</phone:PhoneApplicationPage.Resources>
I want to use the Textlock control in the CSharp code to pass the Text property to the second xaml page, but I can't find the name of the control, it's inaccessible.
Any idea ?
Your binding the Text of the TextBlock so you must have the value in your datacontext. I'd add this value to the Querystirng and navigate to the page.
var text = ((Whatever) DataContext).Nom;
string page2Uri = string.Foramt("/PAge2.xaml?Nom={0}", text);
NavigationService.Navigate(new Uri(page2Uri, UriKind.Relative));
And then to get the data out of the querystring you can use the OnNavigatedTo method in your page, and then inspect this.NavigationContext.QueryString["nom"]
Or have a look into something like the MVVM pattern.
I just use VB.Net but I am sure you can convert.
Just use any shared variable in the application.
Here you can see it in an SourceCode example:
http://www.activevb.de/rubriken/kolumne/kol_30/res/nachtscanner.zip
Just use Public Shared MyText As String
in Application Class. This vairable you can access anywhere.
You can also use INotifyPropertyChanged for that shared property to bind.
Alternatively you can use Navigation Query. Read more here:
How can I pass query string variables with NavigationService.Navigate?
Related
So, I made a really simple attempt to try out data binding from a property of a class that I have, but, for whatever reason, the code actually do anything. It's not throwing any errors, but something must not be working right. I'm just currently testing if it'll behave like I want it to, which, in this case, will set the opacity of a rectangle to zero. Here's the xaml for the Data Template that doesn't seem to want to respond correctly:
<HubSection x:Name="China" Width="440" Height="460" Background="#FF343434" Header="China" IsHeaderInteractive="True" Tapped="{x:Bind HubSectionTapped}" HorizontalAlignment="Left" VerticalAlignment="Center" Margin="50,0,0,0">
<DataTemplate x:DataType="data:MainPageView">
<Grid Height="460" Width="410" VerticalAlignment="Bottom" x:Name="ChinaBackground">
<Image Source="Assets/chinaFlag.bmp" x:Name="ChinaFlag"/>
<Rectangle x:Name="ChinaSelected_Rect" Width="410" Height="30" VerticalAlignment="Bottom" Fill="BlueViolet" Opacity="{x:Bind Opacity1}"/>
</Grid>
</DataTemplate>
</HubSection>
And here's the code behind:
public MainPageView TheMainPageView;
public MainPage()
{
this.InitializeComponent();
timer = new DispatcherTimer();
timer.Tick += Timer_DyanmicResize;
timer.Tick += Timer_SelectionIndicator;
timer.Start();
TheMainPageView = new MainPageView ();
}
And finally, here's the class MainPageView that's referenced:
public class MainPageView
{
public int Opacity1 {get; set;}
public int Opacity2 {get;set;}
public int Opacity3 { get; set; }
public MainPageView()
{
this.Opacity1 = 0;
this.Opacity2 = 0;
this.Opacity3 = 0;
}
}
In the XAML I included the xmlns:data="using:TestApp.Models" (models is the folder in which the class MainPageView is housed). As I said, it's not throwing errors, but it's not doing anything either, so I'm a bit at a loss of where to start addressing this because there aren't any errors to trace back. Thanks in advance for any help you guys can provide
HubSection uses a DataTemplate to define the content for the section, content can be defined inline, or bound to a data source. When using binding in this DataTemplate, we need set DataContext property of HubSection to provide data source for the DataTemplate.
{x:Bind} does not use the DataContext as a default source—instead, it uses the page or user control itself. So it will look in the code-behind of your page or user control for properties, fields, and methods.
This is right when you use {x:Bind} directly in page or user control. While Inside a DataTemplate, there is a little difference.
Inside a DataTemplate (whether used as an item template, a content template, or a header template), the value of Path is not interpreted in the context of the page, but in the context of the data object being templated. So that its bindings can be validated (and efficient code generated for them) at compile-time, a DataTemplate needs to declare the type of its data object using x:DataType.
For more information about Data binding in UWP, please check Data binding in depth.
To fix your issue, you just need to set DataContext in HubSection like following:
<HubSection x:Name="China" Width="440" Height="460" Background="#FF343434" Header="China" IsHeaderInteractive="True" Tapped="{x:Bind HubSectionTapped}" HorizontalAlignment="Left" VerticalAlignment="Center" Margin="50,0,0,0" DataContext="{x:Bind TheMainPageView}">
<DataTemplate x:DataType="data:MainPageView">
<Grid Height="460" Width="410" VerticalAlignment="Bottom" x:Name="ChinaBackground">
<Image Source="Assets/chinaFlag.bmp" x:Name="ChinaFlag"/>
<Rectangle x:Name="ChinaSelected_Rect" Width="410" Height="30" VerticalAlignment="Bottom" Fill="BlueViolet" Opacity="{x:Bind Opacity1}"/>
</Grid>
</DataTemplate>
</HubSection>
Here when using {x:Bind} in HubSection, it uses the page itself as its data source as HubSection is in the page directly. So it can get TheMainPageView field in the code-behind. But for the {x:Bind} in DataTemplate, it can't as
its data source is the data object being templated not the page. So we need to provide this data object by setting DataContext property of HubSection.
Check you output window for errors but I imagine you might see a binding error in there. Opacity is a double, you are using an int so will get a type conversion error.
I have created a RadioButton style which I use across my application. The display part of which uses the content presenter to display whatever content I added to the button:
<ContentPresenter>
<ContentPresenter.ContentTemplate>
<DataTemplate>
<Grid>
<TextBlock Text="{TemplateBinding Content}" />
</Grid>
</DataTemplate>
</ContentPresenter.ContentTemplate>
</ContentPresenter>
I'm then attempting to bind a decimal with a string formatter to the styled button like so:
<RadioButton Content="{Binding Stake, StringFormat={}{0:C}}" Style="{DynamicResource NeutralSelectorButtonStyle}" />
Stake is a decimal within a ViewModel which is set as the DataContext. When I run this up the content coming through is blank.
I made a change using a label in the DataTemplate rather than a TextBlock, this displayed the decimal but had not formatted it.
Can anyone explain why this is happening and possibly provide a solution.
If you require any more information just ask :)
Thanks in advance.
You are almost there just instead of setting the string format inside binding you should use ContentStringFormat property when in ContentControls.
Take a look at this Label (it works with any content control):
<Label Content="{Binding Path=MaxLevelofInvestment}" ContentStringFormat="Amount is {0}"/>
ContentPresenter also has this property:
http://msdn.microsoft.com/en-us/library/system.windows.controls.contentpresenter.contentstringformat%28v=vs.110%29.aspx
Try it out. I hope it works for you.
I need to databind into a element inside my custom class. i've given the ItemSource as the ObservableCollection of telerik:RadTransitionControl via an attached property. However, I need to provide the image member as the source to Image control. I tried the following method and was unsuccessful.
<Grid Background="Black">
<telerik:RadTransitionControl x:Name="radControl" adRotator:AdRotatorExtensions.ItemChangeDelay="0:0:3"
adRotator:AdRotatorExtensions.CurrentSelectedIndex="0"
adRotator:AdRotatorExtensions.IndexChanged="{Binding TopItemCommand, Mode=OneWay}"
adRotator:AdRotatorExtensions.ItemsSource="{Binding Path=ImagePaths}"
VerticalAlignment="Center"
HorizontalAlignment="Center" Width="650">
<telerik:RadTransitionControl.Transition>
<telerik:MotionBlurredZoomTransition />
</telerik:RadTransitionControl.Transition>
<telerik:RadTransitionControl.ContentTemplate>
<DataTemplate>
<Image Source="{Binding Path=ImagePaths.AdImage}" />
</DataTemplate>
</telerik:RadTransitionControl.ContentTemplate>
</telerik:RadTransitionControl>
</Grid>
an ImagePaths object is already set as the DataContext for the item. this means that the binding is already pointing (so to speak) at an instance of the object. so, when you tell it to bind on ImagePaths.AdImage it does not know how to find the property you are looking for. Good news is, all you have to do is provide the path on the object-- remove the ImagePaths part (and the dot) and you should be good to go.
for example...
class something
{
public string someImage {...}
}
<DataTemplate> <!--------- the data context of this item is an instance of
my "something" class, so i need to set the path
to be the property on the object --->
<Image Source="{Binding Path=someImage}" />
</DataTemplate>
here is a very helpful article on debugging bindings in WPF
for more info here is an excellent article on MSDN
here is a datatemplate article from Dr. WPF
i am creating a datatemplate for items in listbox and loading it using
(DataTemplate)XamlReader.Load(template), where template is
string template = String.Concat(#
"<DataTemplate xmlns='http://schemas.microsoft.com/winfx/2006/xaml/presentation' xmlns:x='http://schemas.microsoft.com/winfx/2006/xaml'>
<Border BorderBrush='#334873' BorderThickness='1,1,1,1' Width='450'>
<TextBox Height='72' HorizontalAlignment='Left' Margin='10,10,0,0' TextChanged="OnTextChanged" VerticalAlignment="Top" Width="460" />"
...................
"</Border></DataTemplate>");
i m getting error because of "OnTextChanged" event registerd.
I want to register a event in the template code.
How to do it?
To give you an answer: as you are using a Template it's rather difficult to map an event this way because the template doesn't know where it's put into. So OnTextChanged doesn't mean a thing in this context.
You should consider bindings instead. As you allready use a DataTemplate the usual story would be to Bindd the TextBox-Text property to some model-property
<TextBox Height='72' HorizontalAlignment='Left' Margin='10,10,0,0' Text="{Binding MyTextProperty}" VerticalAlignment="Top" Width="460" />"
Of course the DataContext here should have a property MyTextProperty but without your code (where you use the template) I can give no further details.
I have a WPF Hyperlink that I am able to click and get its NavigateUri property just fine. However, I want to be able to bundle some additional information with the Hyperlink so I can process it in my event handler. This is how it looks right now:
<TextBlock Grid.Row="0">
<Hyperlink ToolTip="{Binding Path=Contact.ToolTipPersonalEmail}"
Name="ContactHyperlink" Foreground="#FF333333"
RequestNavigate="HandleContactEmailClicked"
NavigateUri="{Binding Path=Contact.Email}"
>
<TextBlock Text="{Binding Path=Contact.Fullname}" Width="Auto"
HorizontalAlignment="Stretch"
TextTrimming="CharacterEllipsis"/>
<TextBlock Text="{Binding Path=Data1}" Name="data1" Visibility="Collapsed" />
<TextBlock Text="{Binding Path=Data2}" Name="data2" Visibility="Collapsed" />
</Hyperlink>
</TextBlock>
Basically, in my event handler, I want to be able to access the data inside the two textblocks that have visibility = "Collapsed" (data1 and data2). I liken this to "hidden" data in an HTML form.
I tried messing with the "Inlines" property of Hyperlink but that's not working, and since this is inside a DataTemplate I can't access data1 and data2 by name in my code.
Any ideas?
Thanks.
creating textblocks to hold that data is somewhat... overkill. I'd go with one of these two options:
use databinding, to place a specific
object into the hyperlink, then to
get it back, all you need to do, is
access the DataContext of the
hyperlink,and it will provide you
the class which holds data1 and
data2
attach the object which
populates data1 and data2 into the
Hyperlink's TAG attribute
In your event handler you can do something like this:
ContentPresenter presenter = (ContentPresenter)sender.TemplatedParent;
DataTemplate template = presenter.ContentTemplate;
TextBlock textBlock = (TextBlock)template.FindName("data1", presenter);
Probably not the prettiest way, but it works for me.