First time really using WPF - thought I'd have a go at remaking something I did a while back in Java.
I'm trying to bind the Text value of a TextBlock on a popup to something that gets set in the backend, so I can use one handler method to display any message on said popup.
I've been trying multiple different routes, such as fully binding it in the cs instead of XAML like so:
<--XAML-->
<Popup Margin="89,75,0,0" Name="verif_popup" HorizontalAlignment="Left" VerticalAlignment="Top" IsOpen="False" PopupAnimation="Slide" Placement="Center" Width="100" Height="100" Grid.Column="1">
<Popup.Effect>
<BlurEffect/>
</Popup.Effect>
<Canvas Background="Azure">
<TextBlock Name="VerifTextBlock"/>
</Canvas>
</Popup>
<--CS-->
private void SmallPopupHandler(string text)
{
Binding binding = new("Text")
{
Source = text
};
VerifTextBlock.SetBinding(TextBlock.TextProperty, binding);
verif_popup.IsOpen = true;
}
But it doesn't like the fact that the string isn't a TextBlock property, I sort of knew this wouldn't work but it seems the most logical to me having come from swing. There also doesn't seem to be a way for me to cast it to it and im not in the mood for making my own dependency property rn...
The next thing I tried was to bind the value to a field in the class, but I just got a stackoverflow error (haha nice)
<--XAML-->
<Popup Margin="89,75,0,0" Name="verif_popup" HorizontalAlignment="Left" VerticalAlignment="Top" IsOpen="False" PopupAnimation="Slide" Placement="Center" Width="100" Height="100" Grid.Column="1">
<Popup.Effect>
<BlurEffect/>
</Popup.Effect>
<Canvas Background="Azure">
<Canvas.DataContext>
<local:MainWindow/>
</Canvas.DataContext>
<TextBlock Name="VerifTextBlock" Text="{Binding Popup_message}"/>
</Canvas>
</Popup>
<--CS-->
public partial class MainWindow : Window
{
public string? Popup_message { get; set; }
public MainWindow()
{
InitializeComponent();
this.DataContext = this;
}
I also tried making an interfacing class of sorts to see if that would work around the stackoverflow error (haha) but as im sure you could have guessed by now, that didn't work either...
Kinda pulling my hair out so any help would be greatly appreciated!
Thanks in advance!
You could just set the Text property of the VerifTextBlock directly as suggested by #Clemens:
private void SmallPopupHandler(string text)
{
VerifTextBlock.Text = text;
verif_popup.IsOpen = true;
}
If you really do want to use a binding for whatever reason, then remove the binding path. This should work:
private void SmallPopupHandler(string text)
{
Binding binding = new()
{
Source = text
};
VerifTextBlock.SetBinding(TextBlock.TextProperty, binding);
verif_popup.IsOpen = true;
}
Related
I created a textblock on a XAML form within a ContentControl. When I try to program it, C# doesn't recognize the name and I can't do anything with it.
I tried adding a textblock to the form outside of the Content Control, but that still didn't fix the problem.
Here is the XAML code:
<ContentControl>
<ContentControl.Template>
<ControlTemplate>
<Grid VerticalAlignment="Bottom" Height="250" Margin="0,450,0,0">
<Rectangle Fill="Beige" Stroke="Black" StrokeThickness="3"
Width="639" Height="250" Margin="0,0,0,0"/>
<TextBlock Text="Goal:" FontSize="18" Margin="7,50,0,0"/>
<TextBlock Text="Eaten:" FontSize="18" Margin="7,120,0,0"/>
<TextBlock Text="Remaining:" FontSize="18" Margin="7,190,0,0"/>
<TextBlock Text="Calories:" FontSize="18" Margin="140,10,0,0"/>
<TextBlock Text="Fat(g):" FontSize="18" Margin="270,10,0,0"/>
<TextBlock Text="Carbs(g):" FontSize="18" Margin="380,10,0,0"/>
<TextBlock Text="Protein(g):" FontSize="18" Margin="520,10,0,0"/>
<TextBlock x:Name="lblCalorieGoal" Text="Peb"
TextAlignment="Center" FontSize="18" Margin="-290,50,0,0"/>
</Grid>
</ControlTemplate>
</ContentControl.Template>
<TextBlock Text="TextBlock" TextWrapping="Wrap"/>
</ContentControl>
And then here is the corresponding working C# code:
public LogFood()
{
this.InitializeComponent();
Windows.Storage.ApplicationDataContainer localSettings =
Windows.Storage.ApplicationData.Current.LocalSettings;
Windows.Storage.StorageFolder localFolder =
Windows.Storage.ApplicationData.Current.LocalFolder;
Windows.Storage.ApplicationDataCompositeValue composite =
(Windows.Storage.ApplicationDataCompositeValue)localSettings
.Values["nutritionSettings"];
int calorieMin = Convert.ToInt32(composite["calorieMin"]);
int calorieMax = Convert.ToInt32(composite["calorieMax"]);
int gramsFatMin = Convert.ToInt32(composite["gramsFatMin"]);
int gramsFatMax = Convert.ToInt32(composite["gramsFatMax"]);
int gramsCarbsMin = Convert.ToInt32(composite["gramsCarbsMin"]);
int gramsCarbsMax = Convert.ToInt32(composite["gramsCarbsMax"]);
int gramsProteinMin = Convert.ToInt32(composite["gramsProteinMin"]);
int gramsProteinMax = Convert.ToInt32(composite["gramsProteinMax"]);
lblCalorieGoal.Text = calorieMin;
}
I expect to be able to change the text of the textblock. Instead, I get the error, "The name lblCalorieGoal.Text does not exist in the current context."
The key realization here is that a template is potentially a reusable part of XAML, so anything inside is in fact embedded in it a not "publicly" accessible, as there could potentially be multiple instances of the same template materialized on the view.
That being said, you can still access the materialized children inside the template indirectly by searching for them within the template using VisualTreeHelper -
internal static FrameworkElement FindChildByName(DependencyObject startNode, string name)
{
int count = VisualTreeHelper.GetChildrenCount(startNode);
for (int i = 0; i < count; i++)
{
DependencyObject current = VisualTreeHelper.GetChild(startNode, i);
if (current is FrameworkElement frameworkElement)
{
if (frameworkElement.Name == name)
return frameworkElement;
}
var result = FindChildByName(current, name);
if ( result != null)
{
return result;
}
}
return null;
}
Note, that this works only after the control has loaded (for example in the Page.Loaded event handler -
private void MainPage_Loaded(object sender, RoutedEventArgs e)
{
var block = FindChildByName(ContentRoot, "lblCalorieGoal") as TextBlock;
}
However, this all is not an ideal solution to your problem. Instead, you should either ditch the use of ContentControl altogether and have the controls in the template directly on the page (which would make them directly accessible from the code-behind), or/and use data-binding to bind data directly to appropriate controls. In this case, I would create a class to hold the data, for example:
public class NutritionInfo
{
public string CalorieGoal { get; set; }
}
Now instead of ContentControl.ControlTemplate (which replaces the template of the whole control), you will replace the ContentTemplate instead (which is just the thing which `ControlTemplate in fact displays):
<ContentControl x:Name="ContentRoot">
<ContentControl.ContentTemplate>
<DataTemplate x:DataType="local:NutritionInfo">
... your template
</DataTemplate>
</ContentControl.ContentTemplate>
</ContentControl>
Note we use x:DataType to specify the type we bind to so that we can use x:Bind syntax. Finally, we update the template itself:
<TextBlock x:Name="lblCalorieGoal" Text="{x:Bind CalorieGoal}" ... />
We use x:Bind to bind the text of the TextBlock to the CalorieGoal property. We are almost done, now just set the Content property of the ContentControl to an instance of NutritionInfo (for example via data binding or directly):
ContentRoot.Content = new NutritionInfo()
{
CalorieGoal = "1243"
};
Overall I recommend to read further about how data-binding works in XAML, as that will help you significantly simplify your code and avoid accessing controls directly via x:Name, and decouple UI from your code. See documentation for more info.
I would like to binding as below:
A (in View) <---> B (in View) <----> C (MyData)
Binding A-B : Two way
Binding B-C : One way
Xaml
<Slider x:Name="slider" Minimum="0" Maximum="100" Value="{Binding Path=Text, ElementName=textBox, Mode=TwoWay}"/>
<TextBox x:Name="textBox" Text="{Binding Path=MyValue, Mode=OneWay}"/>
<Button x:Name="button" Content="Button" Click="button_Click"/>
Code Behind:
public int MyValue
{
get { return m_value; }
set
{
m_value = value;
NotifyPropertyChanged("MyValue");
}
}
...
private void button_Click(object sender, RoutedEventArgs e)
{
MyValue = 10;
}
I expect that when I click on button, the value of text box and slider bar will be updated.
However, nothing happen.
Please help me to solve this problem.
Thank in advance.
What you are trying to do is wrong in the architecture, that's why i would suggest you to take a look at some documentation about MVVM
such as:
https://www.codeproject.com/Articles/819294/WPF-MVVM-step-by-step-Basics-to-Advance-Level
or instead of considering just PRISM there are some more that are powerful but more approchable and easier such as MvvmLight:
http://www.dotnetcurry.com/wpf/1037/mvvm-light-wpf-model-view-viewmodel
Hope having been useful
I'm not sure of the correct terminology to use. I created a Windows Store app about a year ago and the main page was created by Visual Studio and I never changed it much. It uses a view model that works fine but I don't know enough to fix problems. Anyhow...
The page uses a GridView to display the contents of CollectionViewSource element to reference an ObservableCollection. This all works fine. The DataTemplate for one of the data items looks like this right now:
<DataTemplate x:Key="TopImageTileTemplate">
<Grid MinHeight="135" Width="350" Margin="0" Background="Transparent">
<Grid.RowDefinitions>
<RowDefinition Height="Auto"/>
<RowDefinition Height="135"/>
</Grid.RowDefinitions>
<TextBlock Text="{Binding Path=ImagePath}" FontSize="33"/>
<usercontrols:WaitingImageControl SourcePath="{Binding Path=ImagePath}" Grid.Row="0" Width="350" Height="165" HorizontalAlignment="Center" VerticalAlignment="Stretch" AutomationProperties.Name="{Binding Title}" Visibility="{Binding TypeDescription, RelativeSource={RelativeSource Mode=TemplatedParent}, Converter={StaticResource TextToVis}}"/>
<usercontrols:WaitingImageControl SourcePath="XXX" Grid.Row="0" Width="350" Height="165" HorizontalAlignment="Center" VerticalAlignment="Stretch" AutomationProperties.Name="{Binding Title}" Visibility="{Binding TypeDescription, RelativeSource={RelativeSource Mode=TemplatedParent}, Converter={StaticResource TextToVis}}"/>
<ProgressRing Opacity="0.5" Foreground="#FF8A57FF" Grid.Row="0" Name="TheProgressControl" IsActive="True" Height="32" Width="32" Background="Transparent" VerticalAlignment="Center" HorizontalAlignment="Center"/>
...
</Grid>
</DataTemplate>
The problem that I have is that the data item for this contains a string called ImagePath that I want to pass into the WaitingImageControl usercontrol and it's not working. The TextBlock works fine and the text displays the ImagePath string just fine. The second WaitingImageControl works fine and the code that handle SourcePath does get passed the "XXX" just fine too. But the first WaitingImageControl never gets passed the ImagePath value from the data item.
This is some sort of binding issue and I know so little about binding that I'm to even sure what to try (or what to show in this question). given that the TextBlock binding works and the second WaitingImageControl binding works, I'm at a loss.
Here's the WaitingImageControl code for the SourcePath property:
public static readonly DependencyProperty SourcePathProperty =
DependencyProperty.Register("SourcePath", typeof(string), typeof(WaitingImageControl), new PropertyMetadata(""));
public string SourcePath
{
get { return m_SourcePath; }
set
{
if( string.IsNullOrEmpty( value ) )
return;
m_SourcePath = value;
ResourcesStore Store = new ResourcesStore();
if( Store.Count() == 0 )
{
var IgnoreMe = CoreApplication.MainView.CoreWindow.Dispatcher.RunAsync( CoreDispatcherPriority.Normal, () =>
{
// No progress and no image...
TheProgressControl.Visibility = Visibility.Collapsed;
TheImage.Visibility = Visibility.Collapsed;
} );
return;
}
ResourceItem Item = Store.getItemByFilename( m_SourcePath );
LocalInboxService.Instance.InboxStatusChanged -= InboxStatusChanged;
InboxStatusChanged( null );
LocalInboxService.Instance.InboxStatusChanged += InboxStatusChanged;
}
}
The code is supposed to show the Image element and hide the ProgressRing element when the image has been downloaded.
And the code for the data item, which again, works just fine when the ImagePath is passed automatically to the TextBlock:
public string ImagePath
{
get
{
return this._imagePath;
}
set
{
this._imagePath = value;
this.SetProperty(ref this._imagePath, value);
}
}
Any help is appreciated making the ImagePath to SourcePath binding (below) work:
<usercontrols:WaitingImageControl SourcePath="{Binding Path=ImagePath}"
Grid.Row="0" Width="350" Height="165" HorizontalAlignment="Center"
VerticalAlignment="Stretch" AutomationProperties.Name="{Binding Title}"
Visibility="{Binding TypeDescription, RelativeSource={RelativeSource
Mode=TemplatedParent}, Converter={StaticResource TextToVis}}"/>
After hours of searching, I found a StackOverflow answer to a similar question. The answer was to add a PropertyChanged function to the Propertymetadata. I'm not sure yet what this actually means or why it is only needed here, but it works properly:
public static readonly DependencyProperty SourceImageResourceIdProperty =
DependencyProperty.Register("SourceImageResourceId", typeof(string), typeof(WaitingImageControl), new PropertyMetadata( string.Empty, OnSourcePathPropertyChanged ));
private static void OnSourcePathPropertyChanged(DependencyObject d, DependencyPropertyChangedEventArgs e)
{
(d as WaitingImageControl).SourceImageResourceId = e.NewValue.ToString();
}
The OnSourcePathPropertyChanged function gets called and the property gets set like it should.
Now I just hope that it wasn't one of the twenty other experiments that actualy fixed this!
As i am not very advanced in C# yet, I try to learn how to make my code more efficient.
I stored a lot of strings in some of the properties.
At the start of the application, i load all the seperatie properties into the textboxes.
I now ise this code to load them all:
private void LoadStoredStrings()
{
txtT1S1.Text = Properties.Settings.Default.strT1L1;
txtT1S2.Text = Properties.Settings.Default.strT1L2;
txtT1S3.Text = Properties.Settings.Default.strT1L3;
txtT1S4.Text = Properties.Settings.Default.strT1L4;
txtT1S5.Text = Properties.Settings.Default.strT1L5;
txtT1S6.Text = Properties.Settings.Default.strT1L6;
txtT1S7.Text = Properties.Settings.Default.strT1L7;
txtT1S8.Text = Properties.Settings.Default.strT1L8;
txtT1S9.Text = Properties.Settings.Default.strT1L9;
txtT1S10.Text = Properties.Settings.Default.strT1L10;
}
Obvious i can see the logic that each stored propertie ending with T1L1 also fits to the txt that ends with T1S1.
I just know this should be done in a more elegant and solid way than what i did now.
Could anyone push me in the right direction?
you can bind your properties directly to your textboxes
<UserControl xmlns:Properties="clr-namespace:MyProjectNamespace.Properties" >
<TextBox Text="{Binding Source={x:Static Properties:Settings.Default}, Path=strT1L1, Mode=TwoWay}" />
If you can get all of those constants into a List<string>, you could use it to bind to an ItemsControl with TextBlock inside:
Code behind or View Model
private ObservableCollection<string> _defaultProperties = new ObservableCollection<string>();
public ObservableCollection<string> DefaultProperties
{
get { return _defaultProperties; }
}
XAML
<ListBox ItemsSource="{Binding Path=DefaultProperties"}>
<ListBox.ItemTemplate>
<DataTemplate>
<!--Just saying "Binding" allows binding directly to the current data context vs. a property on the data context-->
<TextBlock Text="{Binding}"/>
</DataTemplate>
</ListBox.ItemTemplate>
</ListBox>
I am working on creating a tag cloud in Silverlight 2 and trying to bind data from a List collection to a Scale transform on a TextBlock. When running this I get an AG_E_PARSER_BAD_PROPERTY_VALUE error. Is it possible to data bind values to transforms in Silverlight 2? If not could I do something to the effect of FontSize={Binding Weight*18} to multiply the tag's weight by a base font size? I know this won't work, but what is the best way to calculate property values for items in a DataTemplate?
<DataTemplate>
<TextBlock HorizontalAlignment="Stretch" VerticalAlignment="Stretch" TextWrapping="Wrap" d:IsStaticText="False" Text="{Binding Path=Text}" Foreground="#FF1151A8" FontSize="18" UseLayoutRounding="False" Margin="4,4,4,4" RenderTransformOrigin="0.5,0.5">
<TextBlock.RenderTransform>
<TransformGroup>
<ScaleTransform ScaleX="{Binding Path=WeightPlusOne}" ScaleY="{Binding Path=WeightPlusOne}"/>
</TransformGroup>
</TextBlock.RenderTransform>
The issue seems to be Rule #1 from this post:
The target of data binding must be a FrameworkElement.
So since ScaleTransform isn't a FrameworkElement it doesn't support binding. I tried to bind to a SolidColorBrush to test this out and got the same error as with the ScaleTransform.
So in order to get around this you can create a control that exposes a dependency property of your tag data type. Then have a property changed event that binds the properties of your tag data to the properties in the control (one of which would be the scale transform). Here is the code I used to test this out.
items control:
<ItemsControl x:Name="items">
<ItemsControl.ItemTemplate>
<DataTemplate>
<local:TagControl TagData="{Binding}" />
</DataTemplate>
</ItemsControl.ItemTemplate>
</ItemsControl>
tag control xaml:
<UserControl x:Class="SilverlightTesting.TagControl"
xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
>
<TextBlock x:Name="text" TextWrapping="Wrap" FontSize="18" Margin="4,4,4,4">
<TextBlock.RenderTransform>
<ScaleTransform x:Name="scaleTx" />
</TextBlock.RenderTransform>
</TextBlock>
</UserControl>
tag control code:
public partial class TagControl : UserControl
{
public TagControl()
{
InitializeComponent();
}
public Tag TagData
{
get { return (Tag)GetValue(TagDataProperty); }
set { SetValue(TagDataProperty, value); }
}
// Using a DependencyProperty as the backing store for TagData. This enables animation, styling, binding, etc...
public static readonly DependencyProperty TagDataProperty =
DependencyProperty.Register("TagData", typeof(Tag), typeof(TagControl), new PropertyMetadata(new PropertyChangedCallback(TagControl.OnTagDataPropertyChanged)));
public static void OnTagDataPropertyChanged(DependencyObject obj, DependencyPropertyChangedEventArgs e)
{
var tc = obj as TagControl;
if (tc != null) tc.UpdateTagData();
}
public void UpdateTagData()
{
text.Text = TagData.Title;
scaleTx.ScaleX = scaleTx.ScaleY = TagData.Weight;
this.InvalidateMeasure();
}
}
Seems like overkill for just setting a single property, but I couldn't find an easier way.