无废话WPF系列11: 数据转换

2011-02-19 20:15 敏捷的水阅读(1308) 评论(0) 编辑收藏举报

有时我们展现的数据，需要进行转换，比如如果一个学生的成绩过了60，我们显示一个Pass的图片。

XAML:

<Window x:Class="DeepXAML.MainWindow"
        xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
        xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
        xmlns:local="clr-namespace:DeepXAML"       
        xmlns:sys="clr-namespace:System;assembly=mscorlib"
        Title="MainWindow" Height="250" Width="450">
    <Window.Resources>
        <local:ScoreToImageConverter x:Key="sti"></local:ScoreToImageConverter>
    </Window.Resources>
    <StackPanel>
        <ListBox x:Name="listBoxStudents" Margin="10">
            <ListBox.ItemTemplate>
                <DataTemplate>
                    <StackPanel Orientation="Horizontal">
                        <TextBlock Text="{Binding Path=Name}"></TextBlock>                        
                        <Image Source="{Binding Path=Score,Converter={StaticResource sti}}" Height="20"></Image>
                    </StackPanel>
                </DataTemplate>
            </ListBox.ItemTemplate>
        </ListBox>
    </StackPanel>
</Window>

后台代码：

using System;
using System.Collections.Generic;
using System.Windows;
using System.Windows.Data;
using System.Windows.Documents;
 
namespace DeepXAML
{
    public partial class MainWindow : Window
    {
        public MainWindow()
        {
            InitializeComponent();
            List<Student> students = new List<Student>{
             new Student{ Name="Jack", Score=90},
              new Student{Name="Tom", Score=30},
              new Student{ Name="David", Score=80}
            };
            this.listBoxStudents.ItemsSource = students;
        }
 
    }
    public class Student
    {
        public string Name { get; set; }
        public double Score { get; set; }
    }
    public class ScoreToImageConverter : IValueConverter
    {
        public object Convert(object value, Type targetType, object parameter,
            System.Globalization.CultureInfo culture)
        {
            double score = (double)value;
 
            return score >= 60 ? @"\images\pass.gif" : @"\images\nopass.gif";
        }
 
        public object ConvertBack(object value, Type targetType, object parameter,
            System.Globalization.CultureInfo culture)
        {
            throw new NotImplementedException();
        }
    }
}