could you provide me an example of what you explained?
Sure,
1 - Using Tag
In your Style have your DataTrigger as:
<DataTrigger Binding="{Binding Path=Tag,
RelativeSource={RelativeSource Self}}"
Value="{x:Static sys:String.Empty}">
...
</DataTrigger>
as for usage:
<Button x:Name="btnPosition"
Grid.Row="0"
Grid.Column="0"
HorizontalAlignment="Left"
VerticalAlignment="Center"
Command="{Binding PositionFilterCommand}"
Content="{l:Translate position}"
Tag="{Binding SelectedPositions}"
Style="{StaticResource NewButtonStyle}" />
2 - Using Attached Property:
"local:" refers to the xaml namespace alias of your application or if you use different namespaces, the namespace where MyCustomPropertyCollection is declared.
code-behind:
public class MyCustomPropertyCollection {
public static readonly DependencyProperty SomeStringProperty =
DependencyProperty.RegisterAttached(
"SomeString",
typeof(string),
typeof(MyCustomPropertyCollection),
new FrameworkPropertyMetadata(string.Empty));
public static void SetSomeString(UIElement element, string value) {
element.SetValue(SomeStringProperty, value);
}
public static string GetSomeString(UIElement element) {
return (string)element.GetValue(SomeStringProperty);
}
}
Style.DataTrigger
<DataTrigger Binding="{Binding Path=(local:MyCustomPropertyCollection.SomeString),
RelativeSource={RelativeSource Self}}"
Value="{x:Static sys:String.Empty}">
...
</DataTrigger>
usage:
<Button x:Name="btnPosition"
Grid.Row="0"
Grid.Column="0"
HorizontalAlignment="Left"
VerticalAlignment="Center"
Command="{Binding PositionFilterCommand}"
Content="{l:Translate position}"
local:MyCustomPropertyCollection.SomeString="{Binding SelectedPositions}"
Style="{StaticResource NewButtonStyle}" />
3 - Normal Dependency Property
custom Button class:
public class MyButton : Button {
public static readonly DependencyProperty SomeStringProperty =
DependencyProperty.Register(
"SomeString",
typeof(string),
typeof(MyButton),
new FrameworkPropertyMetadata(string.Empty));
public string SomeString {
get {
return (string)GetValue(SomeStringProperty);
}
set {
SetValue(SomeStringProperty, value);
}
}
}
Style in xaml not only needs DataTrigger updated but Style definition too.
so switch
<Style x:Key="NewButtonStyle" TargetType="{x:Type Button}">
to
<Style x:Key="NewButtonStyle" TargetType="{x:Type local:MyButton}">
Style.DataTrigger
<DataTrigger Binding="{Binding Path=SomeString,
RelativeSource={RelativeSource Self}}"
Value="{x:Static sys:String.Empty}">
...
</DataTrigger>
usage:
<local:MyButton x:Name="btnPosition"
Grid.Row="0"
Grid.Column="0"
HorizontalAlignment="Left"
VerticalAlignment="Center"
Command="{Binding PositionFilterCommand}"
Content="{l:Translate position}"
SomeString="{Binding SelectedPositions}"
Style="{StaticResource NewButtonStyle}" />
Tag approach is frowned upon. "Attached Property" is easier to implement but isn't as clear of a indicator of dependencies as a custom class with a normal DP and AP also gets way overused. Take your pick for what you'd prefer.
