在设置新值之前，您必须使ItemSource为空:

You have to null the ItemSource just before you set the new value:

ctlList.ItemsSource = null;
ctlList.ItemsSource = YourObjects;

我建议使用DataContext和Binding代替您的解决方案:

I recommand to use DataContext and Binding instead of your solution:

http://www.codeproject.com/Articles/30905/WPF-DataGrid-Practical-Examples