最近项目中遇到加载数据的性能问题， 原因是.net4.0的虚拟化支持不够完成，有好多bug在4.5才修复。 我们只能利用大家通用的做法来延迟加载数据： 每次加载固定少量的数据，当拖动到底后，继续加载后续相同数量的数据。 思路： 监听ScrollViewer的VerticalOffsetProperty，如果值达到允许滚动的高度ScrollableHeight，则发出event通知外部处理加载逻辑。 使用方法： 1.对于ItemsControl编辑控件模板，在其中的ScrollViewer中加入behavior。 <ScrollViewer x :Name="DG_ScrollViewer" Focusable="false">                                                                                                                                 <i: Interaction.Behaviors>                                                                                                                                                 <local: ReachingBottomBehavior ReachingBottomEvent="LazyLoadingBehavior_OnReachingBottomEvent" />                                                                                                                                 </i: Interaction.Behaviors> 在blend中，比较简单，直接对控件右键，编辑模板/副本，进入ScrollViewer后，把这个behavior拖到ScrollViewer的元素下即可， 生成的代码就是上面的内容。 xmlns:i ="http://schemas.microsoft.com/expression/2010/interactivity" 2.实现上面ReachingBottomEvent的处理逻辑。比如：  private void LazyLoadingBehavior_OnReachingBottomEvent ()        {            var vm = LayoutRoot. DataContext as MainViewModel;            if (vm != null)            {                int count = dtgRoot. Items .Count ;                for (int i = count ; i < count + 30; i ++)                {                    vm .DataItems . Add(                                     new DataItem ()                                     {                                         Item1 = i . ToString(),                                         Item2 = i . ToString() + i .ToString ()                                     });                }            }        } 代码如下： public class ReachingBottomBehavior : Behavior< ScrollViewer>    {        public ReachingBottomBehavior ()        {            // Insert code required on object creation below this point.        }        protected override void OnAttached()        {            base.OnAttached ();            // Insert code that you would want run when the Behavior is attached to an object.            var dpd = DependencyPropertyDescriptor. FromProperty(ScrollViewer .VerticalOffsetProperty, AssociatedType);            dpd.AddValueChanged (                                AssociatedObject,                                (sender,                                 args) =>                                {                                    RaiseReachingBottomEvent();                                });        }        protected override void OnDetaching()        {            base.OnDetaching ();            // Insert code that you would want run when the Behavior is removed from an object.        }        private void RaiseReachingBottomEvent()        {            bool isReachingBottom = AssociatedObject. VerticalOffset >= AssociatedObject .ScrollableHeight;            if (isReachingBottom )            {                if (this .ReachingBottomEvent != null)                {                    this.ReachingBottomEvent ();                }            }        }        public event Action ReachingBottomEvent;    }  [](#)