RegisterAttached 两种绑定方式

1. RegisterAttached 含义：使用指定的属性名称、属性类型和所有者类型注册附加属性
2. 绑定方式：C#绑定、WPF绑定
3. 例：需求DataViewModel为DataView的VM层，在DataViewModel中有ID属性，DataView需要根据ViewModel中的ID变化处理问题

 public class DataViewModel : INotifyPropertyChanged
    {
        public event PropertyChangedEventHandler PropertyChanged;
        public void OnPorpertyChanged(string name)
        {
            if (PropertyChanged != null)
            {
                PropertyChanged.Invoke(this, new PropertyChangedEventArgs(name));
            }
        }

        public int ID
        {
            get { return id; }
            set
            {
                id = value;
                OnPorpertyChanged("ID");
            }
        }
        private int id;
    }

/// <summary>
    /// DataView.xaml 的交互逻辑
    /// </summary>
    public partial class DataView : UserControl
    {
        public DataView()
        {
            InitializeComponent();
            this.DataContext = new DataViewModel();
        }

        public int ID
        {
            get { return (int)GetValue(IDProperty); }
            set { SetValue(IDProperty, value); }
        }

        public static readonly DependencyProperty IDProperty =
            DependencyProperty.RegisterAttached("ID", typeof(int), typeof(DataView), new PropertyMetadata(OnIDChanged));

        private static void OnIDChanged(DependencyObject d, DependencyPropertyChangedEventArgs e)
        {
            var control = d as MainWindow;
            if (control != null)
            {
                control.Background = Convert.ToInt32(e.NewValue) > 0 ? Brushes.Red : Brushes.Green;
            }
        }
    }

　　绑定方式1：

　　在DataView.cs文件中使用Binding属性，如下：

            Binding binding = new Binding("ID");
            binding.Source = DataContext;
            binding.Mode = BindingMode.OneWay;
            this.SetBinding(MainWindow.IDProperty, binding);

 　　绑定方式2：

　　在DataView.xaml文件中对控件的附加依赖属性进行绑定，如下：

<TextBlock Text="{Binding ID}" Width="100" Height="50" Background="DarkGray"/>