数据绑定通知 INotifyPropertyChanged

class BackgroundPath: INotifyPropertyChanged
    {
        BitmapImage bindSource = new BitmapImage(new Uri(PathShow.ImageSelected));      //预设值

        public event PropertyChangedEventHandler PropertyChanged;

        public BitmapImage BindSource
        {
            set
            {
                SetProperty(ref bindSource, value, "BindSource");}           
            get
            {
                return bindSource;}           
        }

        protected bool SetProperty<T>(ref T storage, T value, [CallerMemberName]string propertyName = null)
        {
            if (object.Equals(storage, value))
                return false;

            storage = value;
            OnPropertyChanged(propertyName);
            return true;
        }

        protected void OnPropertyChanged(string propertyName)
        {
            if (PropertyChanged != null)
                PropertyChanged(this, new PropertyChangedEventArgs(propertyName));
        }
　　　}

　　　　　　Binding bind = new Binding()
　　　　　　{
　　　　　　　　Source = new BackgroundPath(),
　　　　　　　　Path = new PropertyPath("BindSource")
　　　　　　};
　　　　　　faceImge.SetBinding(Image.SourceProperty,bind);