/// <summary>引发Changed事件</summary>
 protected virtual void OnChanged(DbChangeEventArgs e)
 {
     if (this.Changed != null)
     {
         this.Changed.Invoke(this, e);
     }
 }
 /// <summary>引发Deleted事件</summary>
 protected void OnDeleted(DbChangeEventArgs e)
 {
     if (this.Deleted != null)
     {
         this.Deleted.Invoke(this, e);
     }
 }