基于WPF实现面包屑控件的示例代码

WPF 实现面包屑控件

• 框架使用.NET4 至 .NET6

• Visual Studio 2022

• 创建 BreadCrumbBar.xaml 设置 VirtualizingStackPanel 为水平方向显示 Orientation="Horizontal"。

• 创建 BreadCrumbBarItem.xaml 设置 ContentPresenter 前显示符号 > ，通过 BreadCrumbBarConvertr 转换器判断如果是当前是第 0 个则隐藏显示符 > 。

• 创建 BreadCrumbBar.cs 继承 ListBox 当选中时获取当前的 SelectedIndex 大于当前的设置 IsEnabled 设置 false 反之则为 true。

实现代码

1）创建 BreadCrumbBar.cs 代码如下:

using System.Collections;
using System.Collections.Specialized;
using System.Windows;
using System.Windows.Controls;

namespace WPFDevelopers.Controls
{
    public class BreadCrumbBar : ListBox
    {
        static BreadCrumbBar()
        {
            DefaultStyleKeyProperty.OverrideMetadata(typeof(BreadCrumbBar), new FrameworkPropertyMetadata(typeof(BreadCrumbBar)));
        }
        public override void OnApplyTemplate()
        {
            base.OnApplyTemplate();
        }
        protected override void OnSelectionChanged(SelectionChangedEventArgs e)
        {
            base.OnSelectionChanged(e);
            for (int i = 0; i <= SelectedIndex; i++)
            {
                var item = (ListBoxItem)ItemContainerGenerator.ContainerFromIndex(i);
                if (item == null) continue;
                if (!item.IsEnabled)
                    item.IsEnabled = true;
            }
            for (int i = Items.Count - 1; i > SelectedIndex; i--)
            {
                var item = (ListBoxItem)ItemContainerGenerator.ContainerFromIndex(i);
                if (item == null) continue;
                if(item.IsEnabled)
                    item.IsEnabled = false;
            }
        }
       
        protected override bool IsItemItsOwnContainerOverride(object item)
        {
            return item is BreadCrumbBarItem;
        }

        protected override DependencyObject GetContainerForItemOverride()
        {
            return new BreadCrumbBarItem();
        }
    }
}

2）创建 BreadCrumbBarItem.cs 代码如下:

using System;
using System.Windows;
using System.Windows.Controls;

namespace WPFDevelopers.Controls
{
    public class BreadCrumbBarItem : ListBoxItem
    {
        private static readonly Type _typeofSelf = typeof(BreadCrumbBarItem);
        static BreadCrumbBarItem()
        {
            DefaultStyleKeyProperty.OverrideMetadata(_typeofSelf,
                new FrameworkPropertyMetadata(_typeofSelf));
        }
    }
}

3）创建 BreadCrumbBar.xaml 代码如下:

<ResourceDictionary
    xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
    xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
    xmlns:controls="clr-namespace:WPFDevelopers.Controls"
    xmlns:converts="clr-namespace:WPFDevelopers.Converts">
    <ResourceDictionary.MergedDictionaries>
        <ResourceDictionary Source="Basic/ControlBasic.xaml" />
    </ResourceDictionary.MergedDictionaries>
    <converts:BreadCrumbBarConvertr x:Key="WD.BreadCrumbBarConvertr" />
    <Style
        x:Key="WD.BreadCrumbBarItem"
        BasedOn="{StaticResource WD.ControlBasicStyle}"
        TargetType="{x:Type controls:BreadCrumbBarItem}">
        <Setter Property="VerticalContentAlignment" Value="Center" />
        <Setter Property="Padding" Value="6,0" />
        <Setter Property="FontWeight" Value="SemiBold" />
        <Setter Property="FontSize" Value="{StaticResource WD.TitleFontSize}" />
        <Setter Property="Template">
            <Setter.Value>
                <ControlTemplate TargetType="{x:Type controls:BreadCrumbBarItem}">
                    <StackPanel Orientation="Horizontal">
                        <Path
                            Name="PART_PathSymbol"
                            Width="9"
                            Height="9"
                            Data="{StaticResource WD.BreadCrumbBarGeometry}"
                            Fill="{DynamicResource WD.PlaceholderTextSolidColorBrush}"
                            IsHitTestVisible="False"
                            Stretch="Uniform">
                            <Path.Visibility>
                                <MultiBinding Converter="{StaticResource WD.BreadCrumbBarConvertr}">
                                    <Binding RelativeSource="{RelativeSource AncestorType=ListBoxItem}" />
                                    <Binding Path="SelectedIndex" RelativeSource="{RelativeSource AncestorType=ListBox}" />
                                </MultiBinding>
                            </Path.Visibility>
                        </Path>
                        <ContentPresenter
                            x:Name="PART_ContentPresenter"
                            Margin="{TemplateBinding Padding}"
                            HorizontalAlignment="{TemplateBinding HorizontalContentAlignment}"
                            VerticalAlignment="{TemplateBinding VerticalContentAlignment}"
                            SnapsToDevicePixels="{TemplateBinding SnapsToDevicePixels}"
                            TextElement.Foreground="{TemplateBinding Foreground}" />
                    </StackPanel>
                    <ControlTemplate.Triggers>
                        <Trigger Property="IsMouseOver" Value="True">
                            <Setter Property="Foreground" Value="{DynamicResource WD.PrimaryMouseOverSolidColorBrush}" />
                        </Trigger>
                    </ControlTemplate.Triggers>
                </ControlTemplate>
            </Setter.Value>
        </Setter>
    </Style>
    <Style
        x:Key="WD.BreadCrumbBar"
        BasedOn="{StaticResource WD.ControlBasicStyle}"
        TargetType="{x:Type controls:BreadCrumbBar}">
        <Setter Property="Height" Value="40" />
        <Setter Property="Margin" Value="5" />
        <Setter Property="ItemsPanel">
            <Setter.Value>
                <ItemsPanelTemplate>
                    <VirtualizingStackPanel Orientation="Horizontal" />
                </ItemsPanelTemplate>
            </Setter.Value>
        </Setter>
        <Setter Property="ItemContainerStyle" Value="{StaticResource WD.BreadCrumbBarItem}" />
        <Setter Property="Template">
            <Setter.Value>
                <ControlTemplate TargetType="{x:Type controls:BreadCrumbBar}">
                    <Border
                        Margin="{TemplateBinding Margin}"
                        Background="{TemplateBinding Background}"
                        BorderBrush="{TemplateBinding BorderBrush}"
                        BorderThickness="{TemplateBinding BorderThickness}">
                        <ScrollViewer Grid.Column="1" HorizontalScrollBarVisibility="Auto">
                            <ItemsPresenter x:Name="ItemsHost" />
                        </ScrollViewer>
                    </Border>
                </ControlTemplate>
            </Setter.Value>
        </Setter>
    </Style>
    <Style BasedOn="{StaticResource WD.BreadCrumbBar}" TargetType="{x:Type controls:BreadCrumbBar}" />
</ResourceDictionary>

4）创建 BreadCrumbBarConverter.cs 代码如下:

using System;
using System.Globalization;
using System.Windows;
using System.Windows.Controls;
using System.Windows.Data;

namespace WPFDevelopers.Converts
{
    public class BreadCrumbBarConvertr : IMultiValueConverter
    {
        public object Convert(object[] values, Type targetType, object parameter, CultureInfo culture)
        {
            var item = values[0] as ListBoxItem;
            var listBox = ItemsControl.ItemsControlFromItemContainer(item) as ListBox;
            if (listBox == null) return Visibility.Collapsed;
            var arrayIndex = listBox.ItemContainerGenerator.IndexFromContainer(item);
            if (arrayIndex == 0)
                return Visibility.Collapsed;
            return Visibility.Visible;
        }

        public object[] ConvertBack(object value, Type[] targetTypes, object parameter, CultureInfo culture)
        {
            throw new NotImplementedException();
        }
    }
}

5）创建 BreadCrumbBarExample.xaml 代码如下:

<Grid>
            <Grid.RowDefinitions>
                <RowDefinition Height="Auto" />
                <RowDefinition />
                <RowDefinition Height="Auto" />
            </Grid.RowDefinitions>
            <wd:BreadCrumbBar
                DisplayMemberPath="Text"
                ItemsSource="{Binding BreadcrumbItems, RelativeSource={RelativeSource AncestorType=UserControl}}"
                SelectedItem="{Binding BreadcrumbItem, RelativeSource={RelativeSource AncestorType=UserControl}}"
                SelectionChanged="BreadCrumbBar_SelectionChanged" />
            <Frame
                Name="myFrame"
                Grid.Row="1"
                NavigationUIVisibility="Hidden" />
            <Button
                Grid.Row="2"
                Width="80"
                Click="btnNext_Click"
                Content="Next"
                Style="{StaticResource WD.SuccessPrimaryButton}" />
        </Grid>

6） BreadCrumbBarExample.xaml.cs 代码如下:

using System.Collections.Generic;
using System;
using System.Windows.Controls;
using System.Collections.ObjectModel;
using System.Windows;
using System.Reflection;

namespace WPFDevelopers.Samples.ExampleViews
{
    /// <summary>
    /// StepExample.xaml 的交互逻辑
    /// </summary>
    public partial class BreadCrumbBarExample : UserControl
    {
        private int index = 0;
        private List<BreadcrumbItem> Breadcrumbs = new List<BreadcrumbItem>();

        public ObservableCollection<BreadcrumbItem> BreadcrumbItems
        {
            get { return (ObservableCollection<BreadcrumbItem>)GetValue(BreadcrumbItemsProperty); }
            set { SetValue(BreadcrumbItemsProperty, value); }
        }

        public static readonly DependencyProperty BreadcrumbItemsProperty =
            DependencyProperty.Register("BreadcrumbItems", typeof(ObservableCollection<BreadcrumbItem>), typeof(BreadCrumbBarExample), new PropertyMetadata(null));

        public BreadcrumbItem BreadcrumbItem
        {
            get { return (BreadcrumbItem)GetValue(BreadcrumbItemProperty); }
            set { SetValue(BreadcrumbItemProperty, value); }
        }

        public static readonly DependencyProperty BreadcrumbItemProperty =
            DependencyProperty.Register("BreadcrumbItem", typeof(BreadcrumbItem), typeof(BreadCrumbBarExample), new PropertyMetadata(null));

        public BreadCrumbBarExample()
        {
            InitializeComponent();
            Loaded += BreadCrumbBarExample_Loaded;

        }

        private void BreadCrumbBarExample_Loaded(object sender, RoutedEventArgs e)
        {
            var breadcrumbItems = new List<BreadcrumbItem>()
            {
                new BreadcrumbItem() { Text = "主页" , Uri=new Uri("pack://application:,,,/WPFDevelopers.Samples;component/ExampleViews/DrawerMenu/HomePage.xaml",UriKind.Absolute ) },
                new BreadcrumbItem() { Text = "Edge", Uri=new Uri("pack://application:,,,/WPFDevelopers.Samples;component/ExampleViews/DrawerMenu/EdgePage.xaml" ,UriKind.Absolute ) },
                new BreadcrumbItem() { Text = "邮件", Uri=new Uri("pack://application:,,,/WPFDevelopers.Samples;component/ExampleViews/DrawerMenu/EmailPage.xaml" ,UriKind.Absolute ) },

            };
            Breadcrumbs = breadcrumbItems;
            myFrame.Navigate(Breadcrumbs[index].Uri);
            BreadcrumbItems = new ObservableCollection<BreadcrumbItem>() { Breadcrumbs[index] };
        }
        private void BreadCrumbBar_SelectionChanged(object sender, SelectionChangedEventArgs e)
        {
            myFrame.Navigate(BreadcrumbItem.Uri);
            index = BreadcrumbItems.IndexOf(BreadcrumbItem);
        }

        private void btnNext_Click(object sender, RoutedEventArgs e)
        {
            index += 1;
            if (index >= Breadcrumbs.Count) return;
            var model = Breadcrumbs[index];
            if (BreadcrumbItems.Contains(model))
            {
                BreadcrumbItem = model;
                return;
            }
            BreadcrumbItems.Add(model);
            BreadcrumbItem = model;
        }

    }
    public class BreadcrumbItem
    {
        public string Text { get; set; }
        public Uri Uri { get; set; }
    }
}

效果图

来源：https://mp.weixin.qq.com/s/fs4TcsjxA_JLrJ7_TWuzpg