Использование IValueConverter является вариантом для вас.
<Grid x:Name="LayoutRoot" Background="Gray">
<Grid.Resources>
<local:NumberToBrushConverter x:Key="NumberToBrushConverter" />
</Grid.Resources>
<ListBox x:Name="List1">
<ListBox.ItemContainerStyle>
<Style TargetType="ListBoxItem">
<Setter Property="Padding" Value="0" />
</Style>
</ListBox.ItemContainerStyle>
<ListBox.ItemTemplate>
<DataTemplate>
<Grid Background="{Binding Converter={StaticResource NumberToBrushConverter}}">
<TextBlock Text="{Binding}" />
</Grid>
</DataTemplate>
</ListBox.ItemTemplate>
</ListBox>
</Grid>
И код позади:
int[] numbers = new int[] { 10, 20, 30 };
List1.ItemsSource = numbers;
И класс ValueConverter:
public class NumberToBrushConverter : IValueConverter
{
public object Convert(object value, Type targetType, object parameter, System.Globalization.CultureInfo culture)
{
if (value is int)
{
switch ((int)value)
{
case 10: return new SolidColorBrush(Colors.Red);
case 20: return new SolidColorBrush(Colors.Green);
case 30: return new SolidColorBrush(Colors.Blue);
}
}
return Colors.Transparent;
}
public object ConvertBack(object value, Type targetType, object parameter, System.Globalization.CultureInfo culture)
{
return null;
}
}