【WPF 】ItemTemplateSelector模板选择器

WPF 的 ItemsControl 数据绑定中，有时会遇到绑定的数据源是多种类型，并且需要对不同类型使用不同的模板。这个时候就需要用到 ItemTemplateSelector。

ItemTemplateSelector 是 DataTemplateSelector 类型，通常需要定义一个类继承 DataTemplateSelector。

项目结构：

 创建一个模板选择类TestDataTemplateSelector：

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading.Tasks;
using System.Windows;
using System.Windows.Controls;

namespace WpfApp2
{
    public class TestDataTemplateSelector: DataTemplateSelector
    {
        public DataTemplate HighTemplate { get; set; }

        public DataTemplate LowTemplate { get; set; }

        public override DataTemplate SelectTemplate(object item, DependencyObject container)
        {
            var stu = (Student)item;
            if (stu.Result > 60)
                return HighTemplate;
            else
                return LowTemplate;
        }
    }
}

MainWindow.xaml代码：
在Window.Resources中定义了两个模板HighTemplate和LowTemplate。

<Window x:Class="WpfApp2.MainWindow"
        xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
        xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
        xmlns:d="http://schemas.microsoft.com/expression/blend/2008"
        xmlns:mc="http://schemas.openxmlformats.org/markup-compatibility/2006"
        xmlns:local="clr-namespace:WpfApp2"
        mc:Ignorable="d"
        Title="MainWindow" Height="450" Width="800">
    <Window.Resources>
        <DataTemplate x:Key="HighTemplate">
            <StackPanel>
                <TextBlock Text="{Binding Name}"/>
                <TextBlock Text="考的非常好！"/>
            </StackPanel>
        </DataTemplate>

        <DataTemplate x:Key="LowTemplate">
            <StackPanel Background="Red">
                <TextBlock Text="{Binding Name}"/>
                <TextBlock Text="电话家长警告！"/>
            </StackPanel>
        </DataTemplate>
    </Window.Resources>
    <Grid>
        <ListBox x:Name="list" ItemsSource="{Binding Model}">
            <ListBox.ItemTemplateSelector>
                <local:TestDataTemplateSelector HighTemplate="{StaticResource HighTemplate}" LowTemplate="{StaticResource LowTemplate}"/>
            </ListBox.ItemTemplateSelector>
        </ListBox>
    </Grid>
</Window>

MainWindow.xaml.cs代码:

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading.Tasks;
using System.Windows;
using System.Windows.Controls;
using System.Windows.Data;
using System.Windows.Documents;
using System.Windows.Input;
using System.Windows.Media;
using System.Windows.Media.Imaging;
using System.Windows.Navigation;
using System.Windows.Shapes;

namespace WpfApp2
{
    /// <summary>
    /// MainWindow.xaml 的交互逻辑
    /// </summary>
    public partial class MainWindow : Window
    {
        public MainWindow()
        {
            InitializeComponent();

            List<Student> stuList = new List<Student>();
            stuList.Add(new Student() { Name = "A", Result = 40 });
            stuList.Add(new Student() { Name = "B", Result = 50 });
            stuList.Add(new Student() { Name = "C", Result = 60 });
            stuList.Add(new Student() { Name = "D", Result = 70 });
            stuList.Add(new Student() { Name = "E", Result = 80 });

            list.DataContext = new { Model = stuList};
        }
    }


    public class Student
    {
        public string Name { get; set; }
        public int Result { get; set; }
    }
}

运行结果：
根据学生成绩结果来选择不同的模板展示数据。