如何按字母顺序对GridViewItem进行分组:Windows应用商店应用

Question

我想按字母顺序对GridViewItem进行分组,并将字母表字母显示为Group Header.
我需要

• GroupItems的标头
• 团体风格
• 项目面板的样式
• GridViewItem的模板

并解释如何将分组的项目添加到CollectionViewSource.

Answer 1

可以使用CollectionViewSource完成GridView分组.在您的Xaml中,在页面的"资源"部分添加CollectionViewSource.确保IsSourceGrouped设置为true:

<Page.Resources>
    <CollectionViewSource x:Name="FruitsCollectionViewSource" IsSourceGrouped="True"/>
</Page.Resources>

我们可以设置源的CollectionViewSource后来从代码隐藏,

然后CollectionViewSource(FruitsCollectionViewSource)应设置为的ItemsSource为您的GridView

 <GridView
        ItemsSource="{Binding Source={StaticResource FruitsCollectionViewSource}}"
        x:Name="FruitGridView"
        Padding="30,20,40,0"
        SelectionMode="None"
        IsSwipeEnabled="false"
        IsItemClickEnabled="True"
        ItemClick="FruitGridView_ItemClick">

          //// GridView ItemTemplate

            <GridView.ItemTemplate>
                <DataTemplate>
                    <Grid HorizontalAlignment="Left" Width="250" Height="250">
                        <Border Background="{ThemeResource ListViewItemPlaceholderBackgroundThemeBrush}">
                            <Image Source="{Binding Path=FruitImageSource}" Stretch="UniformToFill" AutomationProperties.Name="{Binding Title}"/>
                        </Border>
                        <StackPanel VerticalAlignment="Bottom" Background="{ThemeResource ListViewItemOverlayBackgroundThemeBrush}">
                            <StackPanel Orientation="Horizontal">
                                <TextBlock Text="Fruit Name" Foreground="{ThemeResource ListViewItemOverlayForegroundThemeBrush}" Style="{StaticResource TitleTextBlockStyle}" Height="30" Margin="15,0,15,0"/>
                                <TextBlock Text="{Binding Path=FruitName}" Style="{StaticResource TitleTextBlockStyle}" Height="30" Margin="15,0,15,0"/>
                            </StackPanel>
                            <StackPanel Orientation="Horizontal">
                                <TextBlock Text="Fruit Rate" Foreground="{ThemeResource ListViewItemOverlaySecondaryForegroundThemeBrush}" Style="{StaticResource CaptionTextBlockStyle}" TextWrapping="NoWrap" Margin="15,0,87,10"/>
                                <TextBlock Text="{Binding Path=FruitRate}" Foreground="{ThemeResource ListViewItemOverlaySecondaryForegroundThemeBrush}" Style="{StaticResource CaptionTextBlockStyle}" TextWrapping="NoWrap" Margin="15,0,15,10"/>
                            </StackPanel>                          
                        </StackPanel>
                    </Grid>
                </DataTemplate>
            </GridView.ItemTemplate>

            ////Group Style

            <GridView.GroupStyle>
                <GroupStyle>
                    <GroupStyle.HeaderTemplate>
                        <DataTemplate>
                            <TextBlock Text='{Binding Key}' Foreground="Gray" Margin="5" FontSize="30" FontFamily="Segoe UI Light" />
                        </DataTemplate>
                    </GroupStyle.HeaderTemplate>
                    <GroupStyle.Panel>
                        <ItemsPanelTemplate>
                            <VariableSizedWrapGrid MaximumRowsOrColumns="2" Orientation="Horizontal" />
                        </ItemsPanelTemplate>
                    </GroupStyle.Panel>
                </GroupStyle>
            </GridView.GroupStyle>

             //// Item panel Style

            <GridView.ItemsPanel>
                <ItemsPanelTemplate>
                    <ItemsWrapGrid GroupPadding="0,0,70,0" />
                </ItemsPanelTemplate>
            </GridView.ItemsPanel>                     
        </GridView>

现在,您可以从代码隐藏向FruitList添加项目

创建一个ObservableCollection FruitList

public ObservableCollection<Fruit> FruitList { get; set; }

创建一个模型类Fruit

    public class Fruit
    {
        public string FruitName { get; set; }
        public string FruitImageSource { get; set; }
        public string FruitRate { get; set; }
    }

初始化FruitList并将项添加到FruitList

    FruitList.Add(new Fruit { FruitName = "Blackberry", FruitImageSource = "../Assets/blackberry.jpg", FruitRate = "150" });
    FruitList.Add(new Fruit { FruitName = "Apple", FruitImageSource = "../Assets/apple.jpg", FruitRate = "150" });
    FruitList.Add(new Fruit { FruitName = "Orange", FruitImageSource = "../Assets/orange.jpg", FruitRate = "250" });
    FruitList.Add(new Fruit { FruitName = "Bilberry", FruitImageSource = "../Assets/bilberry.jpg", FruitRate = "250" });
    FruitList.Add(new Fruit { FruitName = "Banana", FruitImageSource = "../Assets/banana.jpg", FruitRate = "50" });
    FruitList.Add(new Fruit { FruitName = "Amla", FruitImageSource = "../Assets/amla.jpg", FruitRate = "120" });

现在您可以设置CollectionViewSource的源代码 首先我们需要对FruitList进行排序.然后使用此GetGroupsByLetter()方法按升序或降序对水果名称进行分组.

        FruitList = new ObservableCollection<Fruit>(FruitList .OrderBy(c => c.FruitName));
        FruitsCollectionViewSource.Source = GetGroupsByLetter();

GetGroupsByLetter ()对FruitList中的项进行分组.

    internal List<GroupInfoList<object>> GetGroupsByLetter()
    {
        var groups = new List<GroupInfoList<object>>();

        var query = from item in FruitList
                    orderby ((Fruit)item).FruitName
                    group item by ((Fruit)item).FruitName[0] into g
                    select new { GroupName = g.Key, Items = g };
        foreach (var g in query)
        {
            var info = new GroupInfoList<object>();
            info.Key = g.GroupName;
            foreach (var item in g.Items)
            {
                info.Add(item);
            }

            groups.Add(info);
        }

        return groups;
    }

GroupInfoList:

    public class GroupInfoList<T> : List<object>
    {
        public object Key { get; set; }

        public new IEnumerator<object> GetEnumerator()
        {
            return (System.Collections.Generic.IEnumerator<object>)base.GetEnumerator();
        }
    }

现在你完成了.

您的GridView将如下所示