Question

WPF ListBox选中获取子分类时异常“未将对象引用设置到对象实例” 附代码 求指点

private void secondCate_SelectionChanged(object sender, SelectionChangedEventArgs e)
{
try
{
long cid = (this.secondCate.SelectedItem as ItemCat).Cid;
Cid = cid;
List<ItemCat> icList = gs.getItemcates(cid).ItemCats;

this.Dispatcher.Invoke(new ThreadActionHandler((obj) =>
{
List<ItemCat> iList = obj as List<ItemCat>;
if (iList.Count != 0)
{
this.secondCate.ItemsSource = iList;
}
else
{
WinMsgDialog.Show("该分类无子类目！", "提示");
this.secondCate.ItemsSource = null;
}
}), icList);
}
catch (Exception ex)
{
WinMsgDialog.Show("" + ex.Message, "异常");
} }

Answer 1

楼主最好把断点异常中哪行哪个变量为Null标出来，还有自定义类，否则这样很难看出来啊。
Cid = cid; 这句代码貌似后来没有用到么，意义是神马？