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Learn more about Teams public string Text { get; set; } public DateTime Date { get; set; } public bool IsActive { get; set; }

This observablecollection is used and binded as ItemSource for ListView. The following is DataTemplate for displaying data -

<DataTemplate>
    <ViewCell>
        <Frame OutlineColor="White" HasShadow="False">
             <!-- Data -->
        </Frame>
    </ViewCell>
</DataTemplate>
Since the ObservableCollection is a collection of Data class which has a boolean property, I want to use it in order to change the frame's background color: 
If property IsActive is true - BackgroundColor is Red
If property IsActive is false - BackgroundColor is Blue
I've looked into implementation of Triggers, however I can't seem to get them working correctly, and I'm not sure what I'm missing.
According to Xamarin Documentation I should be able to do :
<Frame>
    <Frame.Trigger>
        <!-- -->
    </Frame.Trigger>  
</Frame>
However that doesn't seem to be possible. Neither is this - 
<Frame>
<Frame.Style>
    <Style TargetType="Frame">
        <Setter Property="BackgroundColor" Value="Blue" />
        <Style.Triggers>
            <DataTrigger Binding="{Binding IsActive}" Value="True">
                <Setter Property="BackgroundColor" Value="Red"/>
            </DataTrigger>
        </Style.Triggers>
    </Style>
</Frame.Style>
</Frame>
The code above gives the following error message:
Xamarin.Forms.Xaml.XamlParseException: Position 28:26. The Property TargetType is required to create a Xamarin.Forms.DataTrigger object.
                Are you sure the line numbers match where your frame style is defined?  I'm not sure about xamarin, but possibly try using the {x:Type } extension instead of relying on string -> type conversion in the TargetType property?
– user1228
                Sep 7, 2016 at 17:30
                Are you setting your BackgroundColor from directly in the <Frame> tag? If so, that property will override any triggered or styled values. Another thing to try is maybe use TargetType={x:Type Frame}, occasionally I see the text string fail to resolve into the actual type, so this prevents that.
– Rachel
                Sep 8, 2016 at 20:38
Not sure about your trigger problem but I think you should be able to accomplish the color changing by first implementing INotifyPropertyChanged on your Data class like so:
public class Data : INotifyPropertyChanged
    public string Text { get; set; }
    public DateTime Date { get; set; }
    private bool _isActive;
    public bool IsActive 
        get { return _isActive; }
            if (value == _isActive)
                return;
            _isActive = value;
            NotifyPropertyChanged("IsActive");
    public event PropertyChangedEventHandler PropertyChanged;
    public void NotifyPropertyChanged(string propertyName)
        if (PropertyChanged != null)
            PropertyChanged(this, new PropertyChangedEventArgs(propertyName));
Then, in your xaml, you should be able to do something like this:
<DataTemplate>
    <ViewCell>
        <Frame Background="{Binding IsActive, Converter={StaticResource IsActiveToColorConverter}}" OutlineColor="White" HasShadow="False">
             <!-- Data -->
        </Frame>
    </ViewCell>
</DataTemplate>
Where IsActiveToColorConverter looks something like:
public class IsActiveToColorConverter : IValueConverter
    public object Convert(object value, Type targetType, object parameter, CultureInfo culture)
        var isActive = (bool) value;
        return isActive ? "Red" : "Blue";
    public object ConvertBack(object value, Type targetType, object parameter, CultureInfo culture)
        throw new NotImplementedException();
                OP Did not mention that boolean property will be changed real time. so NotifyProperty is not required. But Converter is a good option for this scenario. So +1 for that.
– AVK
                Sep 7, 2016 at 17:10
        
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