代码如下:public class DomainBase : INotifyPropertyChanged
{
        private int _id;
        public virtual int ID
        {
            get { return _id; }
            set
            {
                if (value != this._id)
                {
                    _id = value;
                    PropChanged("ID");
                }
            }
        }        public virtual event PropertyChangedEventHandler PropertyChanged;
        public virtual void PropChanged(string fieldName)
        {
            if (PropertyChanged != null)
            {
                PropertyChanged(this, new PropertyChangedEventArgs(fieldName));
            }
        }
}    public class ItemValue : DomainBase
    {
      ...
     }当我把上面的ItemValue对象绑定到RadioButton后,在RadioButton由“选中”变成“没选中”会出现红色边框,围绕在RadioButton周围。如果把属性通知事件放在ItemValue里,如下:public class DomainBase
{
     public virtual int ID { get; set; }
}    public class ItemValue : DomainBase,INotifyPropertyChanged
    {
        private int _id;
        public override int ID
        {
            get { return _id; }
            set
            {
                if (value != this._id)
                {
                    _id = value;
                    PropChanged("ID");
                }
            }
        }        public virtual event PropertyChangedEventHandler PropertyChanged;
        public virtual void PropChanged(string fieldName)
        {
            if (PropertyChanged != null)
            {
                PropertyChanged(this, new PropertyChangedEventArgs(fieldName));
            }
        }
     }这个时候是正常的,RadioButton不会出现红色边框。为什么会出现这样的问题?