使用数据模版选择器及数据触发器

通过定义数据模板触发器，当满足某种条件时执行。如当鼠标悬停时，改变数据的背景色、前景色。
通过定义数据模版选择器，可以根据条件将不同的模板应用于不同的数据。如本例中，年龄小于20的学生和大于20的学生使用不同的数据模板。

先看效果：

鼠标悬停时的效果：

代码如下：
<Window x:Class="DataTemplateDemo.MainWindow"
        xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
        xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
        xmlns:local="clr-namespace:DataTemplateDemo"
        Title="MainWindow" Height="350" Width="525">
    <Window.Resources>
        <local:MyTemplate x:Key="template"></local:MyTemplate>
        <DataTemplate x:Key="ListBoxItem">
            <Border x:Name="brd" BorderBrush="Green" BorderThickness="2" Width="200">
                <StackPanel Orientation="Horizontal">
                    <Label Content="{Binding Path=First}"></Label>
                    <Label Content="{Binding Path=Last}"></Label>
                    <Label Content="{Binding Path=Age}"></Label>
                </StackPanel>
            </Border>
            <DataTemplate.Triggers>
                <Trigger SourceName="brd" Property="IsMouseOver" Value="True">
                    <Setter TargetName="brd" Property="Background" Value="Red"></Setter>
                    <Setter TargetName="brd" Property="BorderBrush" Value="Green"></Setter>
                    <Setter TargetName="brd" Property="BorderThickness" Value="5"></Setter>
                </Trigger>
            </DataTemplate.Triggers>
        </DataTemplate>
        <DataTemplate x:Key="OtherListBoxItem">
            <Border x:Name="brd" BorderBrush="Yellow" BorderThickness="2" Width="200">
                <StackPanel Orientation="Horizontal">
                    <Label Content="{Binding Path=First}"></Label>
                    <Label Content="{Binding Path=Last}"></Label>
                    <Label Content="{Binding Path=Age}"></Label>
                </StackPanel>
            </Border>
            <DataTemplate.Triggers>
                <Trigger SourceName="brd" Property="IsMouseOver" Value="True">
                    <Setter TargetName="brd" Property="Background" Value="Red"></Setter>
                    <Setter TargetName="brd" Property="BorderBrush" Value="Green"></Setter>
                    <Setter TargetName="brd" Property="BorderThickness" Value="5"></Setter>
                </Trigger>
            </DataTemplate.Triggers>
        </DataTemplate>
    </Window.Resources>
    <Grid>
        <ListBox ItemTemplateSelector="{StaticResource template}" x:Name="lstStudent" Margin="73,47,111,72" BorderThickness="0">
            <local:Student First="aa" Last="test" Age="18"></local:Student>
            <local:Student First="bb" Last="test" Age="22"></local:Student>
            <local:Student First="cc" Last="test" Age="19"></local:Student>
            <local:Student First="dd" Last="test" Age="21"></local:Student>
        </ListBox>
    </Grid>
</Window>
MyTemplate类代码如下：
public class MyTemplate:DataTemplateSelector
{
    public override DataTemplate SelectTemplate(object item, DependencyObject container)
    {
        DataTemplate myDataTemplate;
        FrameworkElement element = container as FrameworkElement;
        Student stuItem = item as Student;
        if (stuItem.Age < 20)
        {
            myDataTemplate = element.FindResource("ListBoxItem") as DataTemplate;
        }
        else
        {
            myDataTemplate = element.FindResource("OtherListBoxItem") as DataTemplate;
        }
        return myDataTemplate;
    }
}
Student类代码如下：
namespace DataTemplateDemo
{
    class Student
    {
        string first;

        public string First
        {
            get { return first; }
            set { first = value; }
        }
        string last;

        public string Last
        {
            get { return last; }
            set { last = value; }
        }
        int age;

        public int Age
        {
            get { return age; }
            set { age = value; }
        }
    }
}