张高兴的 UWP 开发笔记：汉堡菜单进阶

　　不同于Windows 8应用，Windows 10引入了“汉堡菜单”这一导航模式。说具体点，就拿官方的天气应用来说，左上角三条横杠的图标外加一个SplitView控件组成的这一导航模式就叫“汉堡菜单”。

　　本文讨论的是如何实现官方的这一样式（点击后左侧出现一个填充矩形），普通实现网上到处都是，有需要的朋友自己百度下吧。

　　下面将介绍两种不同的实现方法，第一种最简单的方法是直接使用 Template 10 模板，第二种就是纯手写了。

　　若有什么不正确的地方望指正，大家共同讨论。

　　1. Template 10 模板

　　使用 Template 10 模板可以快速建立出应用的框架，简单快捷。（帮助文档 https://github.com/Windows-XAML/Template10/wiki ）

　　要使用 Template 10 首先点击 Visual Studio “工具”菜单中的“扩展与更新”，搜索并安装 Template 10（简化搜索可以直接输入t10）

　　安装完成需要重启，重启后按下图找到项目模板新建即可，使用很简单，帮助文档连接也在上方给出。

　　2. 手写

　　先分析一下界面的构成，暂时不看标题栏，由一个设置了 Canvas.ZIndex 的 Button 和一个 SplitView 构成。SplitView.Pane 中又包含了两个ListView（一级菜单和二级菜单）。ListView 里的每个 Item 又由 Rectangle，FontIcon，TextBlock 组成。见下图

　　构成清晰之后实现的思路大概也就清晰了。下面给一个简单的Demo，解决方案结构如下。（GitHub https://github.com/ZhangGaoxing/uwp-demo/tree/master/HamburgerDemo）

　　先创建一个NavMenuItem类

using System;
using System.ComponentModel;
using Windows.UI.Xaml;
using Windows.UI.Xaml.Media;

namespace HamburgerDemo
{
    class NavMenuItem : INotifyPropertyChanged
    {
        // 记录图标字体
        public FontFamily FontFamily { get; set; }
        // 图标的C#转义代码
        public string Icon { get; set; }
        // 标题
        public string Label { get; set; }
        // 导航页
        public Type DestPage { get; set; }
        // 用于左侧矩形的显示
        private Visibility selected = Visibility.Collapsed;
        public Visibility Selected
        {
            get { return selected; }
            set
            {
                selected = value;
                this.OnPropertyChanged("Selected");
            }
        }
        // 双向绑定，用于更新矩形是否显示
        public event PropertyChangedEventHandler PropertyChanged;

        public void OnPropertyChanged(string propertyName)
        {
            PropertyChanged?.Invoke(this, new PropertyChangedEventArgs(propertyName));
        }
    }
}

　　

　　主页面框架代码

<Page
    x:Class="HamburgerDemo.MainPage"
    xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
    xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
    xmlns:local="using:HamburgerDemo"
    xmlns:d="http://schemas.microsoft.com/expression/blend/2008"
    xmlns:mc="http://schemas.openxmlformats.org/markup-compatibility/2006"
    mc:Ignorable="d">

    <Page.Resources>
        <!--菜单的数据模板-->
        <DataTemplate x:Key="DataTemplate">
            <Grid>
                <Grid.ColumnDefinitions>
                    <ColumnDefinition Width="48" />
                    <ColumnDefinition Width="*" />
                </Grid.ColumnDefinitions>

                <Rectangle Fill="{ThemeResource SystemControlBackgroundAccentBrush}" 
                           Visibility="{Binding Selected, Mode=TwoWay}" 
                           HorizontalAlignment="Left" Width="5" Height="48" />
                
                <FontIcon FontFamily="{Binding FontFamily}" Glyph="{Binding Icon}" Foreground="White" 
                          VerticalAlignment="Center" 
                          Margin="-2,0,0,0" Width="48" Height="48" />

                <TextBlock Grid.Column="1" 
                           Text="{Binding Label}" Foreground="White" 
                           Margin="12,0,0,0" VerticalAlignment="Center" />
            </Grid>
        </DataTemplate>
        <!--ListViewItem样式定制-->
        <Style x:Key="NavMenuItemContainerStyle" TargetType="ListViewItem">
            <Setter Property="MinWidth" Value="{StaticResource SplitViewCompactPaneThemeLength}"/>
            <Setter Property="Height" Value="48"/>
            <Setter Property="Padding" Value="0"/>
            <Setter Property="UseSystemFocusVisuals" Value="True" />
            <Setter Property="Template">
                <Setter.Value>
                    <ControlTemplate TargetType="ListViewItem">
                        <ListViewItemPresenter ContentTransitions="{TemplateBinding ContentTransitions}"
                        Control.IsTemplateFocusTarget="True"
                        SelectionCheckMarkVisualEnabled="False"
                        PointerOverBackground="{ThemeResource SystemControlHighlightListLowBrush}"
                        PointerOverForeground="{ThemeResource ListViewItemForegroundPointerOver}"
                        SelectedBackground="Transparent"
                        SelectedForeground="{ThemeResource SystemControlForegroundAccentBrush}"
                        SelectedPointerOverBackground="{ThemeResource SystemControlHighlightListLowBrush}"
                        PressedBackground="{ThemeResource SystemControlHighlightListMediumBrush}"
                        SelectedPressedBackground="{ThemeResource SystemControlHighlightListMediumBrush}"
                        DisabledOpacity="{ThemeResource ListViewItemDisabledThemeOpacity}"
                        HorizontalContentAlignment="{TemplateBinding HorizontalContentAlignment}"
                        VerticalContentAlignment="{TemplateBinding VerticalContentAlignment}"
                        ContentMargin="{TemplateBinding Padding}"/>
                    </ControlTemplate>
                </Setter.Value>
            </Setter>
        </Style>
    </Page.Resources>
    
    <Grid Background="{ThemeResource ApplicationPageBackgroundThemeBrush}">
        <!--汉堡菜单开关-->
        <Button Name="PaneOpenButton" 
                FontFamily="Segoe MDL2 Assets" Content="&#xE700;" Foreground="White" 
                Background="{Binding BackgroundColor}" 
                Width="48" Height="48" 
                VerticalAlignment="Top" Canvas.ZIndex="100" />

        <SplitView Name="RootSplitView" 
                   DisplayMode="CompactOverlay" 
                   CompactPaneLength="48" OpenPaneLength="256" 
                   IsPaneOpen="True">

            <SplitView.Pane>
                <Grid Background="#CC000000">
                    <Grid.RowDefinitions>
                        <!--空出Button的高度-->
                        <RowDefinition Height="48" />
                        <RowDefinition Height="*" />
                        <RowDefinition Height="Auto" />
                    </Grid.RowDefinitions>
                    <!--一级菜单-->
                    <ListView Name="NavMenuPrimaryListView" 
                              Grid.Row="1" VerticalAlignment="Top" 
                              SelectionMode="None" IsItemClickEnabled="True" 
                              ItemTemplate="{StaticResource DataTemplate}" 
                              ItemContainerStyle="{StaticResource NavMenuItemContainerStyle}"/>
                    <!--二级菜单-->
                    <ListView Name="NavMenuSecondaryListView" 
                              Grid.Row="2" VerticalAlignment="Bottom" 
                              SelectionMode="None" IsItemClickEnabled="True" 
                              ItemTemplate="{StaticResource DataTemplate}" 
                              ItemContainerStyle="{StaticResource NavMenuItemContainerStyle}" 
                              BorderBrush="{ThemeResource SystemControlBackgroundAccentBrush}" BorderThickness="0,1,0,0" />
                </Grid>
            </SplitView.Pane>

            <SplitView.Content>
                <Frame Name="RootFrame" />
            </SplitView.Content>

        </SplitView>
        
    </Grid>
</Page>

　　主页面的后台代码

using HamburgerDemo.Views;
using System.Collections.Generic;
using Windows.UI.Xaml;
using Windows.UI.Xaml.Controls;
using Windows.UI.Xaml.Media;

namespace HamburgerDemo
{
    public sealed partial class MainPage : Page
    {
        // 为不同的菜单创建不同的List类型
        private List<NavMenuItem> navMenuPrimaryItem = new List<NavMenuItem>(
            new[]
            {
                new NavMenuItem()
                {
                    FontFamily = new FontFamily("Segoe MDL2 Assets"),
                    Icon = "xE10F",
                    Label = "页面1",
                    Selected = Visibility.Visible,
                    DestPage = typeof(Page1)
                },

                new NavMenuItem()
                {
                    FontFamily = new FontFamily("Segoe MDL2 Assets"),
                    Icon = "xE11A",
                    Label = "页面2",
                    Selected = Visibility.Collapsed,
                    DestPage = typeof(Page1)
                },

                new NavMenuItem()
                {
                    FontFamily = new FontFamily("Segoe MDL2 Assets"),
                    Icon = "xE121",
                    Label = "页面3",
                    Selected = Visibility.Collapsed,
                    DestPage = typeof(Page1)
                },

                new NavMenuItem()
                {
                    FontFamily = new FontFamily("Segoe MDL2 Assets"),
                    Icon = "xE122",
                    Label = "页面4",
                    Selected = Visibility.Collapsed,
                    DestPage = typeof(Page1)
                }

            });

        private List<NavMenuItem> navMenuSecondaryItem = new List<NavMenuItem>(
            new[]
            {
                new NavMenuItem()
                {
                    FontFamily = new FontFamily("Segoe MDL2 Assets"),
                    Icon = "xE713",
                    Label = "设置",
                    Selected = Visibility.Collapsed,
                    DestPage = typeof(Page1)
                }
            });

        public MainPage()
        {
            this.InitializeComponent();
            // 绑定导航菜单
            NavMenuPrimaryListView.ItemsSource = navMenuPrimaryItem;
            NavMenuSecondaryListView.ItemsSource = navMenuSecondaryItem;
            // SplitView 开关
            PaneOpenButton.Click += (sender, args) =>
            {
                RootSplitView.IsPaneOpen = !RootSplitView.IsPaneOpen;
            };
            // 导航事件
            NavMenuPrimaryListView.ItemClick += NavMenuListView_ItemClick;
            NavMenuSecondaryListView.ItemClick += NavMenuListView_ItemClick;
            // 默认页
            RootFrame.SourcePageType = typeof(Page1);
        }

        private void NavMenuListView_ItemClick(object sender, ItemClickEventArgs e)
        {
            // 遍历，将选中Rectangle隐藏
            foreach (var np in navMenuPrimaryItem)
            {
                np.Selected = Visibility.Collapsed;
            }
            foreach (var ns in navMenuSecondaryItem)
            {
                ns.Selected = Visibility.Collapsed;
            }

            NavMenuItem item = e.ClickedItem as NavMenuItem;
            // Rectangle显示并导航
            item.Selected = Visibility.Visible;
            if (item.DestPage != null)
            {
                RootFrame.Navigate(item.DestPage);
            }

            RootSplitView.IsPaneOpen = false;
        }
    }
}

　　运行效果图如下