我们在用到ItemsControl时，有时会用到分组，如ListBox，ListView，DataGrid。WPF的ItemsControl可以实现分组，是依托于GroupStyle，以ListBox为例，他的分组效果图为：
以下为前台：
<ListBox Name="lbMain">
<ListBox.ItemTemplate>
<DataTemplate>
<StackPanel Orientation="Horizontal">
<TextBlock Text="{Binding FileName}"
Width="" />
<TextBlock Text="{Binding AuthorName}"
Width="" />
<TextBlock Text="{Binding UpTime}"
Width="" />
</StackPanel>
</DataTemplate>
</ListBox.ItemTemplate>
<ListBox.GroupStyle>
<GroupStyle>
<GroupStyle.ContainerStyle>
<Style TargetType="{x:Type GroupItem}">
<Setter Property="Template">
<Setter.Value>
<ControlTemplate TargetType="{x:Type GroupItem}">
<Expander IsExpanded="True"
ExpandDirection="Down">
<Expander.Header>
<StackPanel Orientation="Horizontal">
<TextBlock Text="{Binding Path=Name}"
VerticalAlignment="Center" />
<TextBlock Text="{Binding Path=ItemCount, StringFormat=数量:{0}}"
VerticalAlignment="Center"
Margin="5,0,0,0" />
<Button Content="Sale"
Margin="5,0,0,0" />
</StackPanel>
</Expander.Header>
<ItemsPresenter />
</Expander>
</ControlTemplate>
</Setter.Value>
</Setter>
</Style>
</GroupStyle.ContainerStyle>
</GroupStyle>
</ListBox.GroupStyle>
</ListBox>
从16行可以看出，GroupStyle定义的是控件内部样式，所以有人尝试在这里绑实体数据属性的话肯定是失败的，注意25行只能是Name，不管分组的属性叫什么名，这都只能是Name，我写了个Button在里面，如果想知道为什么只能是Name，写个Click处理，把Button的DataContext打印出来就什么都知道了。如果想在这里做更多的处理，比如进行一些负责的运算，可以写加转换器。
这里只是弄了一个原始的Expander装载分组控件，需要美化可以另写样式。
以下是后台：
public class ModelFile
{
public string FileName { get; set; }
public string AuthorName { get; set; }
public string UpTime { get; set; }
} public partial class MainWindow : Window
{
public ObservableCollection<ModelFile> CollectionModelFile = new ObservableCollection<ModelFile>(); public MainWindow()
{
InitializeComponent(); CollectionModelFile.Add(new ModelFile() { FileName = "WPF进化史", AuthorName = "王鹏", UpTime = "2014-10-10" });
CollectionModelFile.Add(new ModelFile() { FileName = "WPF概论", AuthorName = "大飞", UpTime = "2014-10-10" });
CollectionModelFile.Add(new ModelFile() { FileName = "WPF之美", AuthorName = "小虫", UpTime = "2014-10-11" });
CollectionModelFile.Add(new ModelFile() { FileName = "WPF之道", AuthorName = "青草", UpTime = "2014-11-11" });
CollectionModelFile.Add(new ModelFile() { FileName = "WPF之禅", AuthorName = "得瑟鬼", UpTime = "2014-11-11" });
CollectionModelFile.Add(new ModelFile() { FileName = "WPF入门", AuthorName = "今晚吃什么", UpTime = "2014-11-11" });
CollectionModelFile.Add(new ModelFile() { FileName = "WPF神技", AuthorName = "无间道王二", UpTime = "2014-12-12" });
CollectionModelFile.Add(new ModelFile() { FileName = "WPF不为人知之密", AuthorName = "星期八", UpTime = "2014-12-12" });
CollectionModelFile.Add(new ModelFile() { FileName = "WPF之革命", AuthorName = "两把刀", UpTime = "2014-12-12" }); lbMain.ItemsSource = CollectionModelFile; ICollectionView cv = CollectionViewSource.GetDefaultView(lbMain.ItemsSource);
cv.GroupDescriptions.Add(new PropertyGroupDescription("UpTime"));
}
}
重点是28、29行，有了这两句，ListBox就能准确得分组显示了，其他ItemsControl的分组类同。
至此一个简单的ListBox分组显示就完成了，Demo已放群里，需要的可以下载来看。