Use Data Triggers to Change the Appearance of Bound Data : DataTrigger « Windows Presentation Foundation « C# / CSharp Tutorial






<Window x:Class="WpfApplication1.Window1"
    xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
    xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
    xmlns:WpfApplication1="clr-namespace:WpfApplication1"
    x:Name="thisWindow" Title="WPF" Height="240" Width="280">

    <Window.Resources>
        <WpfApplication1:DataItems x:Key="dataItems"/>
        <WpfApplication1:AmountToHeightConverter x:Key="amountToHeightConverter" />
        <DataTemplate x:Key="dataItemtemplate">
            <Rectangle x:Name="rectangle" Width="30"
                VerticalAlignment="Bottom"
                Fill="Green"
                Height="{Binding Path=Amount,Converter={StaticResource amountToHeightConverter}}"/>
            <DataTemplate.Triggers>
                <DataTrigger Binding="{Binding Path=IsPositive}" Value="False">
                    <Setter TargetName="rectangle" Property="Fill" Value="Red"/>
                </DataTrigger>
            </DataTemplate.Triggers>
        </DataTemplate>
    </Window.Resources>
    <StackPanel>
        <ItemsControl ItemsSource="{Binding Source={StaticResource dataItems}}"
            ItemTemplate="{StaticResource dataItemtemplate}">
            <ItemsControl.ItemsPanel>
                <ItemsPanelTemplate>
                    <StackPanel Orientation="Horizontal"/>
                </ItemsPanelTemplate>
            </ItemsControl.ItemsPanel>
        </ItemsControl>

        <Line Stroke="Black" StrokeThickness="2" X1="0" Y1="0" X2="0" Y2="{Binding ElementName=thisWindow, Path=ActualHeight}"/>
        <Line Stroke="Black" StrokeThickness="2" X1="0" Y1="0" X2="{Binding ElementName=thisWindow, Path=ActualWidth}" Y2="0"/>
    </StackPanel>
</Window>
//File:Window.xaml.cs
using System;
using System.Windows.Data;
using System.Globalization;
using System.Collections.ObjectModel;
namespace WpfApplication1
{
    [ValueConversion(typeof (double), typeof (double))]
    public class AmountToHeightConverter : IValueConverter
    {
        public Object Convert(Object value,Type targetType,Object parameter,CultureInfo culture)
        {
            double amount = System.Convert.ToDouble(value);
            if(amount < 0)
                amount = 0;

            return amount;
        }
        public object ConvertBack(object value,Type targetType,object parameter,CultureInfo culture)
        {
            throw new NotImplementedException();
        }
    }
    public class DataItem
    {
        public double Amount
        {
            get;
            set;
        }

        public bool IsPositive
        {
            get
            {
                return Amount >= 0;
            }
        }
    }

    public class DataItems : Collection<DataItem>
    {
        public DataItems()
        {
            this.Add(new DataItem(){Amount=5});
            this.Add(new DataItem(){Amount=8});
            this.Add(new DataItem(){Amount=-5});
            this.Add(new DataItem(){Amount=2});
            this.Add(new DataItem(){Amount=-5});
            this.Add(new DataItem(){Amount=-5});
        }
    }
}
WPF Use Data Triggers To Change The Appearance Of Bound Data








24.143.DataTrigger
24.143.1.Data Trigger SampleData Trigger Sample
24.143.2.Use DataTrigger and MultiDataTrigger.Use DataTrigger and MultiDataTrigger.
24.143.3.Use Data Triggers to Change the Appearance of Bound DataUse Data Triggers to Change the Appearance of Bound Data