WPF MVVM changing property under controltemplate programmatically - wpf

Question

I want to change Border Background programmatically depends on WeekType property. It has All, Even and Odd property. Color of my items are in Border's Background property. So when property is All I want them to stay LightGray, but when All or Even I want to change color of this border
XAML:
<Style TargetType="{x:Type summary:SummaryHourUnitItem}">
<Setter Property="StartTime" Value="{Binding StartTime}" />
<Setter Property="EndTime" Value="{Binding EndTime}" />
<Setter Property="WeekType" Value="{Binding WeekType}" />
<Setter Property="SubGroup" Value="{Binding SubGroup}" />
<Setter Property="Template">
<Setter.Value>
<ControlTemplate TargetType="{x:Type summary:SummaryHourUnitItem}">
<Border Width="Auto" BorderThickness="1,1,1,1" BorderBrush="Black" Background="LightGray"
Margin="0" Padding="3,1.5,0,1.5" >
<ContentPresenter>
<ContentPresenter.Resources>
<Style TargetType="{x:Type TextBlock}">
<Setter Property="FontSize" Value="9" />
<Setter Property="Foreground" Value="Black" />
</Style>
</ContentPresenter.Resources>
</ContentPresenter>
</Border>
</ControlTemplate>
</Setter.Value>
</Setter>
</Style>
SummaryHourUnitItem class:
public class SummaryHourUnitItem : ButtonBase
{
public static readonly DependencyProperty StartTimeProperty =
SummaryTimeSlotPanel.StartTimeProperty.AddOwner(typeof(SummaryHourUnitItem));
public static readonly DependencyProperty EndTimeProperty =
SummaryTimeSlotPanel.EndTimeProperty.AddOwner(typeof(SummaryHourUnitItem));
public static readonly DependencyProperty WeekTypeProperty =
SummaryTimeSlotPanel.WeekTypeProperty.AddOwner(typeof(SummaryHourUnitItem));
public static readonly DependencyProperty SubGroupProperty =
SummaryTimeSlotPanel.SubGroupProperty.AddOwner(typeof(SummaryHourUnitItem));
static SummaryHourUnitItem()
{
DefaultStyleKeyProperty.OverrideMetadata(typeof(SummaryHourUnitItem),
new FrameworkPropertyMetadata(typeof(SummaryHourUnitItem)));
}
public bool StartTime
{
get => (bool) GetValue(StartTimeProperty);
set => SetValue(StartTimeProperty, value);
}
public bool EndTime
{
get => (bool) GetValue(EndTimeProperty);
set => SetValue(EndTimeProperty, value);
}
public WeekType WeekType
{
get => (WeekType) GetValue(WeekTypeProperty);
set
{
SetValue(WeekTypeProperty, value);
}
}
public SubGroup SubGroup
{
get => (SubGroup)GetValue(SubGroupProperty);
set => SetValue(SubGroupProperty, value);
}
}
How can I achieve that?

Answer 1

You must to use a Style Trigger.
<Border Width="Auto" BorderThickness="1,1,1,1" BorderBrush="Black" Background="LightGray"
Margin="0" Padding="3,1.5,0,1.5" >
<Border.Style>
<Style BasedOn="{StaticResource {x:Type Border}}" TargetType="{x:Type Border}">
<Setter Property="Background" Value="LightGray" />
<Style.Triggers>
<DataTrigger Binding="{Binding WeekType}" Value="XXXX">
<Setter Property="Background" Value="Red" />
</DataTrigger>
</Style.Triggers>
</Style>
</TextBox.Style>
<ContentPresenter>
<ContentPresenter.Resources>
<Style TargetType="{x:Type TextBlock}">
<Setter Property="FontSize" Value="9" />
<Setter Property="Foreground" Value="Black" />
</Style>
</ContentPresenter.Resources>
</ContentPresenter>
</Border>
I hope it works for you.