[wpf] How to set DataGrid's row Background, based on a property value using data bindings

In my XAML code, I want to set the Background color of each row, based on a value of the object in one specific row. I have an ObservableCollection of z, and each of the z has a property called State. I started out with something like this in my DataGrid:

<DataGrid.RowStyle>
    <Style TargetType="DataGridRow">
        <Setter Property="Background" 
                Value="{Binding z.StateId, Converter={StaticResource StateIdToColorConverter}}"/>
     </Style>
</DataGrid.RowStyle>

This is a wrong approach because x is not a property in my ViewModel class.

In my ViewModel class I have an ObservableCollection<z> which is the ItemsSource of this DataGrid, and a SelectedItem of type z.

I could bind the color to SelectedItem, but this will only change one row in the DataGrid.

How can I, based on one property change this rows backgroundcolor?

This question is related to wpf xaml wpfdatagrid

The answer is


Use a DataTrigger:

<DataGrid ItemsSource="{Binding YourItemsSource}">
    <DataGrid.RowStyle>
        <Style TargetType="DataGridRow"> 
            <Style.Triggers>
                <DataTrigger Binding="{Binding State}" Value="State1">
                    <Setter Property="Background" Value="Red"></Setter>
                </DataTrigger>
                <DataTrigger Binding="{Binding State}" Value="State2">
                    <Setter Property="Background" Value="Green"></Setter>
                </DataTrigger>
            </Style.Triggers>
        </Style>
    </DataGrid.RowStyle>
</DataGrid>

In XAML, add and define a RowStyle Property for the DataGrid with a goal to set the Background of the Row, to the Color defined in my Employee Object.

<DataGrid AutoGenerateColumns="False" ItemsSource="EmployeeList">
   <DataGrid.RowStyle>
        <Style TargetType="DataGridRow">
             <Setter Property="Background" Value="{Binding ColorSet}"/>
        </Style>
   </DataGrid.RowStyle>

And in my Employee Class

public class Employee {

    public int Id { get; set; }
    public string Name { get; set; }
    public int Age { get; set; }

    public string ColorSet { get; set; }

    public Employee() { }

    public Employee(int id, string name, int age)
    {
        Id = id;
        Name = name;
        Age = age;
        if (Age > 50)
        {
            ColorSet = "Green";
        }
        else if (Age > 100)
        {
            ColorSet = "Red";
        }
        else
        {
            ColorSet = "White";
        }
    }
}

This way every Row of the DataGrid has the BackGround Color of the ColorSet Property of my Object.


The same can be done without DataTrigger too:

 <DataGrid.RowStyle>
     <Style TargetType="DataGridRow">
         <Setter Property="Background" >
             <Setter.Value>
                 <Binding Path="State" Converter="{StaticResource BooleanToBrushConverter}">
                     <Binding.ConverterParameter>
                         <x:Array Type="SolidColorBrush">
                             <SolidColorBrush Color="{StaticResource RedColor}"/>
                             <SolidColorBrush Color="{StaticResource TransparentColor}"/>
                         </x:Array>
                     </Binding.ConverterParameter>
                 </Binding>
             </Setter.Value>
         </Setter>
     </Style>
 </DataGrid.RowStyle>

Where BooleanToBrushConverter is the following class:

public class BooleanToBrushConverter : IValueConverter
{
    public object Convert(object value, Type targetType, object parameter, CultureInfo culture)
    {
        if (value == null)
            return Brushes.Transparent;

        Brush[] brushes = parameter as Brush[];
        if (brushes == null)
            return Brushes.Transparent;

        bool isTrue;
        bool.TryParse(value.ToString(), out isTrue);

        if (isTrue)
        {
            var brush =  (SolidColorBrush)brushes[0];
            return brush ?? Brushes.Transparent;
        }
        else
        {
            var brush = (SolidColorBrush)brushes[1];
            return brush ?? Brushes.Transparent;
        }
    }

    public object ConvertBack(object value, Type targetType, object parameter, CultureInfo culture)
    {
        throw new NotImplementedException();
    }
}