INotitypropertyChanged

WPF数据绑定（要是后台类对象的属性值发生改变，通知在“client界面与之绑定的控件值”也发生改变须要实现INotitypropertyChanged接口）

MainWindow.xaml

<Window x:Class="WpfApplication1.MainWindow"
        xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
        xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
        Title="MainWindow" Height="350" Width="525" Loaded="Window_Loaded">
    <Grid>
        <TextBox Text="{Binding Name}"  Height="23" HorizontalAlignment="Left" Margin="122,68,0,0" Name="txtName" VerticalAlignment="Top" Width="120" />
        <TextBox Text="{Binding Age}" Height="23" HorizontalAlignment="Left" Margin="122,124,0,0" Name="txtAge" VerticalAlignment="Top" Width="120" />
        <TextBlock Height="23" HorizontalAlignment="Left" Margin="82,71,0,0" Name="textBlock1" Text="姓名" VerticalAlignment="Top" />
        <TextBlock Height="23" HorizontalAlignment="Left" Margin="82,127,0,0" Name="textBlock2" Text="年龄" VerticalAlignment="Top" />
        <Button Content="Age++" Height="23" HorizontalAlignment="Left" Margin="262,71,0,0" Name="button1" VerticalAlignment="Top" Width="75" Click="button1_Click" />
        <Button Content="显示Age" Height="23" HorizontalAlignment="Left" Margin="262,124,0,0" Name="button2" VerticalAlignment="Top" Width="75" Click="button2_Click" />
    </Grid>
</Window>

MainWindow.xaml.cs

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
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 WpfApplication1
{
    /// <summary>
    /// MainWindow.xaml 的交互逻辑
    /// </summary>
    public partial class MainWindow : Window
    {
        Person p1 = new Person();
        public MainWindow()
        {
            InitializeComponent();
        }

        private void Window_Loaded(object sender, RoutedEventArgs e)
        {
            p1.Name = "李大钊";
            p1.Age = 28;

            txtName.DataContext = p1;
            txtAge.DataContext = p1;
        }

        private void button1_Click(object sender, RoutedEventArgs e)
        {
            p1.Age++;
        }

        private void button2_Click(object sender, RoutedEventArgs e)
        {
            MessageBox.Show((p1.Age).ToString());
        }
    }
}

Model

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.ComponentModel;

namespace WpfApplication1
{
    /// <summary>
    /// INotifyPropertyChanged接口是向client发出某一属性值已经更改的通知
    /// INotifyPropertyChanged是.net内置的接口，数据绑定DataContext是否实现了INotityPropertyChanged接口，假设实现了，就会监听PropertyChanged得知属性的变化
    /// 假设要求后台对象的值发送改变，界面的值也跟着变，则须要实现INotityPropertyChanged接口。而且在对象属性值变化后触发事件
    /// 假设说后台对象的值会不变，则没有必要实现这个接口
    /// </summary>
    public class Person:INotifyPropertyChanged
    {
        private string name;
        public string Name
        {
            get
            {
                return name;
            }

            set
            {
               this.name = value;
               if (PropertyChanged != null)
               {   //假设Name属性发生了改变，则触发这个事件
                   PropertyChanged(this, new PropertyChangedEventArgs("Name"));
               }
            }
        }

        private int age;
        public int Age
        {
            get
            {
                return age;
            }

            set
            {
                this.age = value;
                //假设有人（数据绑定的对象来监听的）监听这个事件（假设有人监听就是不等于null,假设没人监听这个事件就等于null）
                if (PropertyChanged != null)
                { 
                    //假设Age属性发生了改变，则触发这个事件
                    PropertyChanged(this,new PropertyChangedEventArgs("Age"));
                }
            }
        }

        public event PropertyChangedEventHandler PropertyChanged;
        
    }
}