Change the view element property based on ViewModel property change

Question

I would like to change the color of my Label in the view based on a type in my ViewModel. For ex:

My class in ViewModel has a bool property like following:

MyViewModel
{
public bool IsBlueColor {get; set;} //Here I will raise the `PropertyChanged`
}

How can I wrap a trigger for this value to update Foreground property of my label. All I could figure out was changing the property of UI element based on its on property using DataTrigger. But not based on viewmodel.

How can I achieve this in xaml?

Right now I am doing this:

<Label.Style>
    <Style TargetType="Label" BasedOn="{StaticResource LabelStyle}">
        <Style.Triggers>
            <DataTrigger   Binding="{Binding Path=IsBlueColor, RelativeSource={RelativeSource AncestorType={x:Type local2:MyViewModel}}}" Value="True">
                <Setter Property="Foreground" Value="RoyalBlue"/>
            </DataTrigger>
            <DataTrigger  Binding="{Binding Path=IsBlueColor, RelativeSource={RelativeSource AncestorType={x:Type local2:MyViewModel}}}" Value="False">
                <Setter Property="Foreground" Value="White"/>
            </DataTrigger>
        </Style.Triggers>
    </Style>
</Label.Style>

Answer 1

Change the style triggers to:

<Style.Triggers>
           <DataTrigger Binding="{Binding Path=IsBlueColor}" Value="True">
               <Setter Property="Foreground" Value="RoyalBlue"/>
           </DataTrigger>
           <DataTrigger  Binding="{Binding Path=IsBlueColor}" Value="False">
                <Setter Property="Foreground" Value="White"/>
           </DataTrigger> 
</Style.Triggers>

Check implementation of INotifyPropertyChanged in ViewModel.

this works in a sample for me.

Sample :

class LabelViewModel:INPC
{
 public event PropertyChangedEventHandler PropertyChanged=new delegate{};
 bool _isBlueColor;
 public bool IsBlueColor
 {
  get
  {
    return _isBlueColor;
  }
  set
  {
    _isBlueColor=value;
    OnPropertyChange();
  }
}
public OnPropertyChange([CallerMemberName] string propname="")
{
  PropertyChanged.Invoke(this,ew PropertyChangedEventArgs(propname));
}

}

Create an instance of LabelViewModel(labelVM) & assign to label1.DataContext=labelVM;