gridview - 如何按字母顺序对 GridView 项目进行分组 : Windows Store App

Question

我想按字母顺序对 GridViewItems 进行分组，并将字母显示为组标题。
我需要

• GroupItem 的标题
• 团队风格
• 项目面板的样式
• GridViewItem 模板

并解释如何将分组的项目添加到 CollectionViewSource。

Answer 1

GridView 分组可以使用 CollectionViewSource 完成。在您的 Xaml 中，在页面的资源部分添加一个 CollectionViewSource。确保 IsSourceGrouped 设置为 true:

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

我们可以稍后在代码隐藏中设置CollectionViewSource的Source，

然后 CollectionViewSource(FruitsCollectionViewSource) 应该设置为您的 GridView

的 ItemsSource

 <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您的 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并将项目添加到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" });

现在你可以设置你的源 CollectionViewSource为此，我们首先需要对我们的 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() 将 FruitList 中的项目分组。

    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;
    }

组信息列表:

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

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

现在你已经完成了。

您的 GridView 将如下所示