DependencyProperty使用中的3个场景，讨论PropertyChangedCallback

1：项目结构图

2：控件SilverlightControl1

前台：

后台：

    public partial class SilverlightControl1 : UserControl    {        public SilverlightControl1()        {            InitializeComponent();        }        public static readonly DependencyProperty StudentProperty = DependencyProperty.Register("Student", typeof(Student), typeof(SilverlightControl1), new PropertyMetadata(new PropertyChangedCallback(xxx)));        public Student Student        {            get            {                return (Student)GetValue(StudentProperty);            }            set            {                SetValue(StudentProperty, value);                            }        }        static void xxx(DependencyObject d, DependencyPropertyChangedEventArgs e)        {            MessageBox.Show("sss");        }    }

3：调用方

前台：

后台：

    public partial class MainPage : UserControl    {        public MainPage()        {            InitializeComponent();        }        Student student1 = new Student() { StudentName = "hzh" + DateTime.Now.ToFileTime(), Age = 99 };        Student student2 = new Student() { StudentName = "lmj" + DateTime.Now.ToFileTime(), Age = 99 };        Student student3 = new Student() { StudentName = "lh" + DateTime.Now.ToFileTime(), Age = 99 };        //初始化        private void Button_Click(object sender, RoutedEventArgs e)        {            //采用非绑定机制            uc1.Student = student1;            //采用非绑定机制，对DataContext赋值            uc2.DataContext = student2;            //采用绑定机制            uc3.DataContext = student3;        }        //改Model值        private void Button_Click1(object sender, RoutedEventArgs e)        {            student1.StudentName = "lmj" + DateTime.Now.ToString();            student1.Age = 90;            student2.StudentName = "hzh" + DateTime.Now.ToString();            student2.Age = 90;            student3.StudentName = "hzh" + DateTime.Now.ToString();            student3.Age = 90;        }        //更换Model        private void Button_Click_1(object sender, RoutedEventArgs e)        {            student1 = new Student() { StudentName = "hzh" + DateTime.Now.ToFileTime(), Age = 99 };            student2 = new Student() { StudentName = "lmj" + DateTime.Now.ToFileTime(), Age = 99 };            student3 = new Student() { StudentName = "lh" + DateTime.Now.ToFileTime(), Age = 99 };        }    }

4：结论

无论是第一种方式，还是第三种方式，都能触发PropertyChangedCallback，而如果调用采用第二种方式，则不会触发PropertyChangedCallback。

源码：SilverlightApplication320110609.rar