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:

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 1 <ListBox Name="lbMain">
 2     <ListBox.ItemTemplate>
 3         <DataTemplate>
 4             <StackPanel Orientation="Horizontal">
 5                 <TextBlock Text="{Binding FileName}"
 6                            Width="150" />
 7                 <TextBlock Text="{Binding AuthorName}"
 8                            Width="100" />
 9                 <TextBlock Text="{Binding UpTime}"
10                            Width="100" />
11             </StackPanel>
12         </DataTemplate>
13     </ListBox.ItemTemplate>
14     <ListBox.GroupStyle>
15         <GroupStyle>
16             <GroupStyle.ContainerStyle>
17                 <Style TargetType="{x:Type GroupItem}">
18                     <Setter Property="Template">
19                         <Setter.Value>
20                             <ControlTemplate TargetType="{x:Type GroupItem}">
21                                 <Expander IsExpanded="True"
22                                           ExpandDirection="Down">
23                                     <Expander.Header>
24                                         <StackPanel Orientation="Horizontal">
25                                             <TextBlock Text="{Binding Path=Name}"
26                                                        VerticalAlignment="Center" />
27                                             <TextBlock Text="{Binding Path=ItemCount, StringFormat=数量:{0}}"
28                                                        VerticalAlignment="Center"
29                                                        Margin="5,0,0,0" />                                   
30                                             <Button Content="Sale"
31                                                     Margin="5,0,0,0" />
32                                         </StackPanel>
33                                     </Expander.Header>
34                                     <ItemsPresenter />
35                                 </Expander>
36                             </ControlTemplate>
37                         </Setter.Value>
38                     </Setter>
39                 </Style>
40             </GroupStyle.ContainerStyle>
41         </GroupStyle>
42     </ListBox.GroupStyle>
43 </ListBox>
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  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:

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1 public class ModelFile
 2 {
 3     public string FileName { get; set; }
 4     public string AuthorName { get; set; }
 5     public string UpTime { get; set; }
 6 }
 7 
 8 public partial class MainWindow : Window
 9 {
10     public ObservableCollection<ModelFile> CollectionModelFile = new ObservableCollection<ModelFile>();
11 
12     public MainWindow()
13     {
14         InitializeComponent();
15 
16         CollectionModelFile.Add(new ModelFile() { FileName = "WPF进化史", AuthorName = "王鹏", UpTime = "2014-10-10" });
17         CollectionModelFile.Add(new ModelFile() { FileName = "WPF概论", AuthorName = "大飞", UpTime = "2014-10-10" });
18         CollectionModelFile.Add(new ModelFile() { FileName = "WPF之美", AuthorName = "小虫", UpTime = "2014-10-11" });
19         CollectionModelFile.Add(new ModelFile() { FileName = "WPF之道", AuthorName = "青草", UpTime = "2014-11-11" });
20         CollectionModelFile.Add(new ModelFile() { FileName = "WPF之禅", AuthorName = "得瑟鬼", UpTime = "2014-11-11" });
21         CollectionModelFile.Add(new ModelFile() { FileName = "WPF入门", AuthorName = "今晚吃什么", UpTime = "2014-11-11" });
22         CollectionModelFile.Add(new PropertyGroupDescription("UpTime"));
}
31 }

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。