Windows Phone 8.1 列表控件（2）：分组数据

说到 List 控件，Windows Phone 8.1 上推荐使用的是 ListView 和 GridView。

而这两个控件实在太多东西可讲了，于是分成三篇来讲：

（1）基本

（2）分组数据

（3）多数据呈现

ListView 和 GridView 的最大差别就是：ListView 是一条条依序排列的，而 GridView 则是一块块依序排列的，因此 ListView 中的一项就会占据整整一行或者一列，而 GridView 的一项只会占据它应有的大小，一行或一列中可以放置多项。

而两者在其它方面上基本一致，因此下文只对 ListView 进行介绍，GridView 其实也一样的。

---

分组数据（GroupingData）

分组数据也就是将数据按首字母或自定义属性进行分组，然后用户就能通过点击首字母或自定义属性达到快速定位的目的：

构建过程：

（1）准备已分好组的数据

数据的分组可分为两类，一是根据项的首字母或拼音分组，二是根据项的自身属性分组。

1）首字母或拼音分组

public static List<AlphaKeyGroup<SampleItem>> GetAlphaGroupSampleItems()
{
    ObservableCollection<SampleItem> data = new ObservableCollection<SampleItem>();
    data.Add(new SampleItem() { Title = "k1", Content = "k1", Image = "ms-appx:/Images/k1.png", Group = "Kill La Kill" });
    data.Add(new SampleItem() { Title = "w2", Content = "w2", Image = "ms-appx:/Images/w2.png", Group = "Wu Yu" });
    data.Add(new SampleItem() { Title = "k3", Content = "k3", Image = "ms-appx:/Images/k3.png", Group = "Kill La Kill" });
    data.Add(new SampleItem() { Title = "t4", Content = "t4", Image = "ms-appx:/Images/t4.png", Group = "Tiger" });
    data.Add(new SampleItem() { Title = "t5", Content = "t5", Image = "ms-appx:/Images/t5.png", Group = "Tiger" });
    data.Add(new SampleItem() { Title = "x6", Content = "x6", Image = "ms-appx:/Images/x6.png", Group = "Xi De Ni Ya" });
    data.Add(new SampleItem() { Title = "x7", Content = "x7", Image = "ms-appx:/Images/x7.png", Group = "Xi De Ni Ya" });
    data.Add(new SampleItem() { Title = "x8", Content = "x8", Image = "ms-appx:/Images/x8.png", Group = "Xi De Ni Ya" });
    data.Add(new SampleItem() { Title = "x9", Content = "x9", Image = "ms-appx:/Images/x9.png", Group = "Xi De Ni Ya" });
    data.Add(new SampleItem() { Title = "x10", Content = "x10", Image = "ms-appx:/Images/x10.png", Group = "Xi De Ni Ya" });
    data.Add(new SampleItem() { Title = "x11", Content = "x11", Image = "ms-appx:/Images/x11.png", Group = "Xi De Ni Ya" });

    List<AlphaKeyGroup<SampleItem>> groupData = AlphaKeyGroup<SampleItem>.CreateGroups(
                                                                                data,
                                                                                (SampleItem s) => { return s.Title; },
                                                                                true);
    return groupData;
}

AlphaKeyGroup 类为自己写的分组类：

public class AlphaKeyGroup<T>
{
    const string GlobeGroupKey = "\uD83C\uDF10";

    public string Key { get; private set; }

    public List<T> InternalList { get; private set; }

    public AlphaKeyGroup(string key)
    {
        Key = key;
        InternalList = new List<T>();
    }

    private static List<AlphaKeyGroup<T>> CreateDefaultGroups(CharacterGroupings slg)
    {
        List<AlphaKeyGroup<T>> list = new List<AlphaKeyGroup<T>>();

        foreach( CharacterGrouping cg in slg )
        {
            if( cg.Label == "" )
                continue;
            if( cg.Label == "..." )
            {
                list.Add(new AlphaKeyGroup<T>(GlobeGroupKey));
            }
            else
            {
                list.Add(new AlphaKeyGroup<T>(cg.Label));
            }
        }

        return list;
    }

    public static List<AlphaKeyGroup<T>> CreateGroups(IEnumerable<T> items, Func<T, string> keySelector, bool sort)
    {
        CharacterGroupings slg = new CharacterGroupings();
        List<AlphaKeyGroup<T>> list = CreateDefaultGroups(slg);

        foreach( T item in items )
        {
            int index = ;
            {
                string label = slg.Lookup(keySelector(item));
                index = list.FindIndex(alphakeygroup => (alphakeygroup.Key.Equals(label, StringComparison.CurrentCulture)));
            }

            if( index >=  && index < list.Count )
            {
                list[index].InternalList.Add(item);
            }
        }

        if( sort )
        {
            foreach( AlphaKeyGroup<T> group in list )
            {
                group.InternalList.Sort((c0, c1) => { return keySelector(c0).CompareTo(keySelector(c0)); });
            }
        }

        return list;
    }
}

AlphaKeyGroup

2）自身属性分组

public static List<KeyedList<string, SampleItem>> GetKeyGroupSampleItems()
{
    ObservableCollection<SampleItem> data = new ObservableCollection<SampleItem>();
    data.Add(new SampleItem() { Title = "k1", Content = "k1", Image = "ms-appx:/Images/k1.png", Group = "Kill La Kill" });
    data.Add(new SampleItem() { Title = "w2", Content = "w2", Image = "ms-appx:/Images/w2.png", Group = "Wu Yu" });
    data.Add(new SampleItem() { Title = "k3", Content = "k3", Image = "ms-appx:/Images/k3.png", Group = "Kill La Kill" });
    data.Add(new SampleItem() { Title = "t4", Content = "t4", Image = "ms-appx:/Images/t4.png", Group = "Tiger" });
    data.Add(new SampleItem() { Title = "t5", Content = "t5", Image = "ms-appx:/Images/t5.png", Group = "Tiger" });
    data.Add(new SampleItem() { Title = "x6", Content = "x6", Image = "ms-appx:/Images/x6.png", Group = "Xi De Ni Ya" });
    data.Add(new SampleItem() { Title = "x7", Content = "x7", Image = "ms-appx:/Images/x7.png", Group = "Xi De Ni Ya" });
    data.Add(new SampleItem() { Title = "x8", Content = "x8", Image = "ms-appx:/Images/x8.png", Group = "Xi De Ni Ya" });
    data.Add(new SampleItem() { Title = "x9", Content = "x9", Image = "ms-appx:/Images/x9.png", Group = "Xi De Ni Ya" });
    data.Add(new SampleItem() { Title = "x10", Content = "x10", Image = "ms-appx:/Images/x10.png", Group = "Xi De Ni Ya" });
    data.Add(new SampleItem() { Title = "x11", Content = "x11", Image = "ms-appx:/Images/x11.png", Group = "Xi De Ni Ya" });

    var groupedItems = from item in data
                       orderby item.Group
                       group item by item.Group into itemsByGroup
                       select new KeyedList<string, SampleItem>(itemsByGroup);
    return groupedItems.ToList();
}

KeyedList 为自己编写的类：

public class KeyedList<TKey, TItem>: List<TItem>
{
    public TKey Key { protected set; get; }

    public IEnumerable<TItem> InternalList { protected set; get; }

    public KeyedList(TKey key, IEnumerable<TItem> items)
        : base(items)
    {
        Key = key;
        InternalList = items;
    }

    public KeyedList(IGrouping<TKey, TItem> grouping)
        : base(grouping)
    {
        Key = grouping.Key;
        InternalList = grouping;
    }
}

KeyedList

（2）插入 CollectionViewSource

<Page.Resources>
    <CollectionViewSource x:Key="ItemsGrouped"
                          IsSourceGrouped="True"
                          ItemsPath="InternalList"
                          Source="{Binding GroupData, Source={Binding}}"/>
</Page.Resources>

这里的 GroupData 即为第一步中准备好的已分组的数据。

然后将 ListView 的 ItemsSource 绑定为 CollectionViewSources：

<ListView ItemsSource="{Binding Source={StaticResource ItemsGrouped}}"/>

（3）编写 ListView 的 GroupStyle.HeaderTemplate

GroupStyle.HeaderTemplate 也就是 ListView 里每一组的标题的模板，可自由定义：

<ListView.GroupStyle>
    <GroupStyle HidesIfEmpty="True" >
        <GroupStyle.HeaderTemplate>
            <DataTemplate>
                <Border Background="{StaticResource PhoneAccentBrush}"
                        BorderBrush="{StaticResource PhoneAccentBrush}"
                        BorderThickness="2"
                        Width="62" Height="62" Margin="0,0,18,0"
                        HorizontalAlignment="Stretch">
                    <TextBlock Text="{Binding Key}"
                            Foreground="{StaticResource PhoneForegroundBrush}"
                            FontSize="48"
                            Padding="6"
                            FontFamily="{StaticResource PhoneFontFamilySemiLight}"
                            HorizontalAlignment="Left"
                            VerticalAlignment="Center"/>
                </Border>
            </DataTemplate>
        </GroupStyle.HeaderTemplate>
    </GroupStyle>
</ListView.GroupStyle>

（4）将 ListView 放入 SemanticZoom 里

到目前为止，ListView 已经能正常将分组数据显示在页面上了，最后一步也就是将 ListView 放入 SemanticZoom 控件中。

<SemanticZoom>
    <SemanticZoom.ZoomedInView>
        <!-- 前三步写好的 ListView -->
    </SemanticZoom.ZoomedInView>
    <SemanticZoom.ZoomedOutView>
        <!-- 缩放后的跳转界面 -->
        <GridView ItemsSource="{Binding Source={StaticResource ItemsGrouped}, Path=CollectionGroups}"
                  Background="#AA000000">
            <GridView.ItemTemplate>
                <DataTemplate>
                    <Border Background="{Binding Converter={StaticResource BackgroundConverter}}"
                            Padding="5">
                        <Border Background="{Binding}"
                                Width="82" Height="82"
                                HorizontalAlignment="Left">
                            <TextBlock Text="{Binding Group.Key}"
                                       Foreground="{Binding Converter={StaticResource ForegroundConverter}}"
                                       FontSize="48"
                                       Padding="6"
                                       HorizontalAlignment="Left" VerticalAlignment="Center"/>
                        </Border>
                    </Border>
                </DataTemplate>
            </GridView.ItemTemplate>
        </GridView>
    </SemanticZoom.ZoomedOutView>
</SemanticZoom>

其中的两个 Converter 是对分组中有无该项的区分显示：

<Page
    x:Class="ListControls.GroupListViewPage"
    xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
    xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
    xmlns:local="using:ListControls"
    xmlns:d="http://schemas.microsoft.com/expression/blend/2008"
    xmlns:mc="http://schemas.openxmlformats.org/markup-compatibility/2006"
    xmlns:prim="using:Windows.UI.Xaml.Controls.Primitives"
    mc:Ignorable="d"
    DataContext="{Binding DefaultViewModel, RelativeSource={RelativeSource Self}}"
    Background="{ThemeResource ApplicationPageBackgroundThemeBrush}">

    <Page.Resources>
        <prim:JumpListItemBackgroundConverter x:Key="BackgroundConverter"/>
        <prim:JumpListItemForegroundConverter x:Key="ForegroundConverter"/>
    </Page.Resources>

</Page

Convertor