I have a Templates.xaml
file in my project which contains the ResourceDictionary
of styles.
I want to bind Direction
of a DropShadowEffect
to MyNamespace.MyPage.LightDirection
. Currently I did this:
// MyPage.xaml.cs
/// <summary>
/// Direction of light source for shadows and gradients.
/// </summary>
public static double LightDirection => 45;
<!--Templates.xaml-->
<Style x:Key="ControlButtons" TargetType="{x:Type Button}">
<Setter Property="Effect">
<Setter.Value>
<DropShadowEffect ShadowDepth="4" Direction="{Binding LightDirection}" Color="Black" Opacity="0.5" BlurRadius="4" />
</Setter.Value>
</Setter>
<!--Other Setters-->
</Style>
<!--MyPage.xaml-->
<Page x:Name="MyPage"
DataContext="{Binding ElementName=MyPage}">
<!--MyPage as some other default attributes which I didn't write here-->
<Grid>
<Button x:Name="MyButton" Style="{StaticResource ControlButtons}">
My Button
</Button>
</Grid>
</Page>
It works. The shadow direction is set to LightDirection
and program runs normally. However, while debugging, debugger shows a binding error:
Cannot find governing FrameworkElement or FrameworkContentElement for target element.
What is my mistake? How should I prevent this error?
CodePudding user response:
I suggest making a constant
namespace MyNamespace
{
public class Constants
{
public static double LightDirection { get; set; }
}
}
XAML
<ResourceDictionary xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
xmlns:local="clr-namespace:MyNamespace">
<Style x:Key="ControlButtons" TargetType="{x:Type Button}">
<Setter Property="Effect">
<Setter.Value>
<DropShadowEffect ShadowDepth="4"
Direction="{x:Static local:Constants.LightDirection}"
Color="Black"
Opacity="0.5"
BlurRadius="4" />
</Setter.Value>
</Setter>
</Style>
</ResourceDictionary>
Or declare constant directly in XAML
<ResourceDictionary xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
xmlns:local="clr-namespace:MyNamespace"
xmlns:sys="clr-namespace:System;assembly=mscorlib" >
<sys:Double x:Key="LightDirection">45.0</sys:Double>
<Style x:Key="ControlButtons" TargetType="{x:Type Button}">
<Setter Property="Effect">
<Setter.Value>
<DropShadowEffect ShadowDepth="4"
Direction="{StaticResource LightDirection}"
Color="Black"
Opacity="0.5"
BlurRadius="4" />
</Setter.Value>
</Setter>
</Style>
</ResourceDictionary>