Develop Reference

How to clip PathFigure with shape? [duplicate]

Is there a way that I can use a normal Rectangle (shape) as part of a clip for another object in XAML. It seems like I should be able to, but the solution is eluding me..
<Canvas>
<Rectangle Name="ClipRect" RadiusY="10" RadiusX="10" Stroke="Black" StrokeThickness="0" Width="32.4" Height="164"/>
<!-- This is the part that I cant quite figure out.... -->
<Rectangle Width="100" Height="100" Clip={Binding ElementName=ClipRect, Path="??"/>
</Canvas>
I know that I can use a 'RectangleGeometry' type approach, but I am more interested in the solution in terms of the code presented above.

Try Shape.RenderedGeometry Property.
<Rectangle Width="100" Height="100"
Clip="{Binding ElementName=ClipRect, Path=RenderedGeometry}" />

ClipRect.DefiningGeometry nd ClipRect.RenderedGeometry contain only the RadiusX and RadiusY values but not also Rect.
I'm not sure what exactly you want to achieve (it's not clear to me from your sample) but you could write an IValueConverter which would extract the info you require from the referenced Rectangle:
public class RectangleToGeometryConverter : IValueConverter
{
public object Convert(object value, Type targetType, object parameter, System.Globalization.CultureInfo culture)
{
var rect = value as Rectangle;
if (rect == null || targetType != typeof(Geometry))
{
return null;
}
return new RectangleGeometry(new Rect(new Size(rect.Width, rect.Height)))
{
RadiusX = rect.RadiusX,
RadiusY = rect.RadiusY
};
}
public object ConvertBack(object value, Type targetType, object parameter, System.Globalization.CultureInfo culture)
{
throw new NotImplementedException();
}
}
You would then use this converter in your binding definition:
<Rectangle Width="100" Height="100"
Clip="{Binding ElementName=ClipRect, Converter={StaticResource RectangleToGeometryConverter}}">
Of course you need to add the converter to your resources first:
<Window.Resources>
<local:RectangleToGeometryConverter x:Key="RectangleToGeometryConverter" />
</Window.Resources>

Converter not firing after collection update

I have ran into a issue with the converters... They are not triggering once the bound collection is updated although they trigger when the collection is first populated. I would like to have them fire whenever there is a change in the collection.
So far I have built a simple converter:
public class TableConverter : IValueConverter
{
public object Convert(object value, Type targetType, object parameter, CultureInfo culture)
{
VM.Measurement t = ((VM.Measurement)((TextBlock)value).DataContext);
if (t.Delta != null)
{
if (Math.Abs((double)t.Delta) < t.Tol)
return "Green";
else
return "Red";
}
else
return "Red";
}
public object ConvertBack(object value, Type targetType, object parameter, CultureInfo culture)
{
throw new NotImplementedException();
}
}
which is linked to a style
<conv:TableConverter x:Key="styleConvStr"/>
<Style x:Key="CellStyleSelectorTol" TargetType="syncfusion:GridCell">
<Setter Property="Background" Value="{Binding RelativeSource={RelativeSource Self}, Path=Content, Converter={StaticResource styleConvStr}}" />
</Style>
Which is used in this DataGrid
<syncfusion:SfDataGrid x:Name="CheckGrid" BorderBrush="White" Grid.Row="1" Grid.Column="1" AllowEditing="True" ItemsSource="{Binding ChecksList, Mode=TwoWay}" Background="White" SnapsToDevicePixels="False"
ColumnSizer="None" AllowResizingColumns="False" AllowTriStateSorting="True" AllowDraggingColumns="False" CurrentCellEndEdit="CheckGrid_CurrentCellEndEdit" AutoGenerateColumns="False"
NavigationMode="Cell" HeaderRowHeight="30" RowHeight="21" GridPasteOption="None" Margin="20 10 10 10" AllowGrouping="True" SelectedItem="{Binding SelectedLine, Mode=TwoWay}"
SelectionUnit="Row" SelectionMode="Single" RowSelectionBrush="#CBACCB" VirtualizingPanel.IsVirtualizing="True" Visibility="Visible">
<syncfusion:GridTextColumn Width="100" ColumnSizer="SizeToCells" AllowEditing="True" MappingName="Measured" CellStyle="{StaticResource CellStyleSelectorTol}" HeaderText="Measured" TextAlignment="Center" AllowFiltering="False" FilterBehavior="StringTyped"/>
The VM contains an Observable Collection which implements NotifyPropertyChanged all the way down to the Measurement Class. The properties fire up nicely so it is not a binding issue.
private ObservableCollection<Measurement> _checkList = new ObservableCollection<Measurement>();
public ObservableCollection<Measurement> ChecksList
{
get
{
return _checkList;
}
set
{
_checkList = value;
NotifyPropertyChanged();
}
}
Any help with this would be greatly appreciated.
Thanks
EDIT:
Here is the code that updates the collection. Apologies for it being quite messy. Lineitem is the selected line for which Measured and Delta are updated. These are properly displayed in the grid once modified.
public void NewMeasurement(VM.Measurement measurementShell)
{
using (VMEntity DB = new VMEntity())
{
var Check = CheckSets.Where(x => x.ID == SelectedLine.ID).First();
if (Check.Measurement == null)
{
Check.Measurement = measurementShell.Index;
var Lineitem = ChecksList.Where(x => x.ID == SelectedLine.ID).First();
var measurement = DB.Measurements.Where(x => x.Index == Check.Measurement).First();
Lineitem.Measured = (double)measurement.measurement1;
Lineitem.Delta = Lineitem.Measured - Lineitem.Target;

OK, it looks like the problem is that you are changing properties of the cell content item (LineItem, in the NewMeasurement() method), but it's still the same object, so the cell's content doesn't change. The cell's Content is the source for the binding. If that doesn't change, the binding won't wake up and update the target. You're raising PropertyChanged, but this particular binding has no way of knowing you want it to listen to this object for those property changes. Easy enough fix: We'll start telling it exactly what to listen for.
Fortunately the solution means simplifying some of your code. Passing a UI control into a value converter is exotic and not necessary.
What you care about in the converter is Measurement.Delta and Measurement.Tol. When either one changes, the Binding should update its target. You don't want to do that in a clever way. You just want a Binding for each one. That's a Binding's job.
So tell the Binding that you care about those properties, and rewrite the converter to accept both of them as parameters.
<Style x:Key="CellStyleSelectorTol" TargetType="syncfusion:GridCell">
<Setter
Property="Background"
>
<Setter.Value>
<MultiBinding Converter="{StaticResource styleConvStr}">
<Binding Path="Delta" />
<Binding Path="Tol" />
</MultiBinding>
</Setter.Value>
</Setter>
</Style>
Converter:
public class TableConverter : IMultiValueConverter
{
public object Convert(object[] values, Type targetType, object parameter, CultureInfo culture)
{
// I'm inferring that Measurement.Delta is Nullable<double>; if that's
// not the case, change accordingly. Is it Object instead?
double? delta = (double?)values[0];
double tol = (double)values[1];
if (delta.HasValue && Math.Abs(delta.Value) < tol)
{
return "Green";
}
return "Red";
}
public object[] ConvertBack(object value, Type[] targetTypes, object parameter, CultureInfo culture)
{
throw new NotImplementedException();
}
}

Windows Phone update/refresh binding

I have a textblock in my listbox called "feedTitle" which I want to change the forground color of. I use Foreground="{Binding Converter={StaticResource NewsTextColorConverter}}" for the binding of the forground color. Now the strange problem is that, if I choose a color in the listpicker("Lys" or "Dark" value) it runs the IValueConverter Convert method, but it dont show the color in the GUI, only if I restart my whole app it shows the color I chosen. It's like it only set the color of the forground of the textblock once.
MainPage.xaml
<ListBox Grid.Row="1" Name="feedListBox" ScrollViewer.VerticalScrollBarVisibility="Auto" SelectionChanged="feedListBox_SelectionChanged">
<ListBox.ItemTemplate>
<DataTemplate>
<StackPanel VerticalAlignment="Top">
<TextBlock TextDecorations="Underline" FontSize="24" Name="feedTitle" TextWrapping="Wrap" Margin="12,0,0,0" Foreground="{Binding Converter={StaticResource NewsTextColorConverter}}" Text="{Binding Title.Text, Converter={StaticResource RssTextTrimmer}}" />
</StackPanel>
</DataTemplate>
</ListBox.ItemTemplate>
</ListBox>
And in my app file:
App.xaml
<Application.Resources>
<converter:NewsTextColorConverter xmlns:converter="clr-namespace:NordjyskeRss" x:Key="NewsTextColorConverter" />
</Application.Resources>
I use a listpicker where a user select the value "Mørk" or "Lys" and then I want the textblock forground color to update its forground color. I call the Convert method and pass null as arguments, it seems to run the method fine:
MainPage.cs
private void lpkThemes_SelectionChanged(object sender, SelectionChangedEventArgs e)
{
// Make sure we don't handle the event during initiation.
if (e.RemovedItems != null && e.RemovedItems.Count > 0)
{
if (this.lpkThemes.SelectedItem != null)
{
settings[THEMES_SETTING_KEY] = lpkThemes.SelectedItem.ToString();
if (lpkThemes.SelectedItem.ToString() == "Mørk")
{
n.Convert(null, null, null, null);
}
else
{
n.Convert(null, null, null, null);
}
}
}
}
This is where I use a IValueConverter to check for what color to use on the textblock and then add it:
MainPage.cs
public class NewsTextColorConverter : IValueConverter
{
protected IsolatedStorageSettings settings = IsolatedStorageSettings.ApplicationSettings;
protected const string THEMES_SETTING_KEY = "Themes";
public object Convert(object value, Type targetType, object parameter, System.Globalization.CultureInfo culture)
{
if (settings.Contains(THEMES_SETTING_KEY))
{
string themesValue = (string)settings[THEMES_SETTING_KEY];
if (themesValue == "Mørk")
{
return new SolidColorBrush(Colors.Green);
}
else
{
return new SolidColorBrush(Colors.Blue);
}
}
return new SolidColorBrush(Colors.Green);
//throw new NotSupportedException("ColorToBurshConverter only supports converting from Color and String");
}
public object ConvertBack(object value, Type targetType, object parameter, System.Globalization.CultureInfo culture)
{
throw new NotImplementedException();
}
}

I think you need to redesign your app in the following way:
Add the following line into your app.xaml or page resources: <SolidColorBrush x:Key="brushListItemsForeground" Color="#FFFFFFFF" />
Replace Foreground="{Binding Converter={StaticResource NewsTextColorConverter}}" with Foreground="{StaticResource brushListItemsForeground}"
In your SelectionChanged:
var brush = (SolidColorBrush)Application.Current.Resources["brushListItemsForeground"]; if you’ve added the brush to app.xaml, or = (SolidColorBrush)this.Resources["brushListItemsForeground"]; if you’ve added the brush to page resources. Then change the Color property of the brush based on your settings.
P.S. There’re also other correct ways: e.g. create a SettingsContainer class that implements INotifyPropertyChanged, add it into some resource dictionary <local:SettingsContainer x:Key="mySettings" />, then bind to its properties e.g. Foreground="{Binding listItemsForeground, Source={StaticResource mySettings}}", when you need to change the value, change the listItemsForeground property of your class and raise PropertyChanged.
Currently, you’re abusing value converter using then as value providers, they were not designed for that, and that is why you have issues updating those values.

How to make IValueConverter return text with different fontsizes, superscripts and/or subscripts

Can anyone please let me know how I could make a Converter return text with varying font-sizes, so that the bound textblock can display it? If this is not possible with a TextBlock, I can use alternative element as well.
Here is the code that I have right now, this obviously doesn't work
In my XAML file:
<TextBlock Text="{Binding Converter={StaticResource LabelFormatConerter}}"/>
In my XAML.cs file:
public class LabelFormatConerter : IValueConverter
{
public object Convert(object value, Type targetType, object parameter, System.Globalization.CultureInfo culture)
{
TextBlock tb = new TextBlock();
Run runLargeFont = new Run();
runLargeFont.FontSize = 18;
runLargeFont.Text = "Larger Font Text";
tb.Inlines.Add(runBase);
Run runSmallFont = new Run();
runSmallFont.FontSize = 8;
runSmallFont.BaselineAlignment = BaselineAlignment.Superscript;
runSmallFont.Text = "Smaller Font Text";
tb.Inlines.Add(runSmallFont);
return tb.Text;
}
public object ConvertBack(object value, Type targetType, object parameter, System.Globalization.CultureInfo culture)
{
throw new NotImplementedException();
}
}

This should work for you:
<TextBlock FontFamily="Calibri">
<Run>Normal Text</Run>
<Run Typography.Variants="Superscript">Test</Run>
<Run Typography.Variants="Subscript">7</Run>
</TextBlock>
Not all fonts support super\subscripts, so I had to specify it explictly.
What will be your input? Two/three separate values, or one value that you need to split into a normal value, superscript and subscript?

This might be possible to do with a TextBlock but I don't know how. Your converter returns a collection of Run objects, while the Text property expects a string.
An alternative is to user an items control:
<ItemsControl ItemsSource="{Binding Converter={StaticResource LabelFormatConerter}}" />
and return
tb.Inlines
from your converter. (ideally you just create just a collection inside your converter, not a new TextBlock)

A converter is not the right tool for this job - this is what ContentTemplate is there for. Simply use a ContentControl, bind the data to the Content property and display the data however your want to in your ContentTemplate:
<ContentControl Content="{Binding Person}">
<ContentControl.ContentTemplate>
<DataTemplate>
<TextBlock>
<Run FontSize="18" Text="{Binding FirstName}" />
<Run FontSize="8" Text="{Binding LastName}" />
</TextBlock>
</DataTemplate>
</ContentControl.ContentTemplate>
</ContentControl>

Converter not found? XamlParseException: Cannot find a Resource with the Name/Key StringTruncator

I've included the StringTruncator converter in my App.Resources
xmlns:app="clr-namespace:Tabbed_Browser">
<!--Application Resources-->
<Application.Resources>
<ResourceDictionary>
<app:StringTruncator x:Key="StringTruncator" />
<app:StringTruncatorFav x:Key="StringTruncatorFav" />
<app:AppInfo x:Key="AppInfo" />
<app:BooleanToVisibilityConverter x:Key="BooleanToVisibilityConverter" /
</ResourceDictionary>
</Application.Resources>
Then in the UserControl XML I refer to it via this code
<Grid x:Name="LayoutRoot" Background="{StaticResource PhoneChromeBrush}">
<TextBlock TextWrapping="NoWrap" x:Name="txtPageTitle"
Text="{Binding BrowserViewModel.PageTitle, Converter={StaticResource StringTruncator}}"
FontSize="{StaticResource PhoneFontSizeSmall}"
VerticalAlignment="Top"/>
The StringTruncator is a simple converter that append ... if the string exceed certain length.
namespace Tabbed_Browser
{
public class StringTruncator : IValueConverter
{
public object Convert(object value, Type targetType, object parameter, CultureInfo culture)
{
if (value == null)
return "";
string str = value.ToString();
int maxChars = 44;
return str.Length <= maxChars ? str : str.Substring(0, maxChars) + "...";
}
public object ConvertBack(object value, Type targetType, object parameter, CultureInfo culture)
{
throw new NotImplementedException();
}
}
}
But then I run the project I get the following. Removing the StringTruncator converter in the code eliminate the error but I need to use the converter. What am I missing?
{System.Windows.Markup.XamlParseException:
Cannot find a Resource with the Name/Key StringTruncator [Line: 15 Position: 22]
at System.Windows.Application.LoadComponent(Object component, Uri resourceLocator)
at Tabbed_Browser.User_Controls.UCAddressBar.InitializeComponent()
at Tabbed_Browser.User_Controls.UCAddressBar..ctor()}

You should use DynamicResource instead, this way it will be applied at runtime. Or you can add resources to the Usercontrol.Resources itself. Or you can do like that also, but you must add namespace to UserControl also:
Text="{Binding BrowserViewModel.PageTitle, Converter={app:StringTruncator}}"