Prism（八） 导航

源码地址 - WineMonk/PrismStudy: Prism框架学习 (github.com)

导航基础

视图

ViewA/B.xaml

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<UserControl x:Class="ModuleA.Views.ViewA"
             xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
             xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
             xmlns:prism="http://prismlibrary.com/"             
             prism:ViewModelLocator.AutoWireViewModel="True">
    <StackPanel>
        <TextBlock Text="{Binding Title}" FontSize="48" HorizontalAlignment="Center" VerticalAlignment="Center" />
        <TextBlock Text="{Binding PageViews}" FontSize="24" HorizontalAlignment="Center" VerticalAlignment="Center"/>
    </StackPanel>
</UserControl>

ViewA/BViewModel.cs

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public class ViewAViewModel : BindableBase
{
    public ViewAViewModel()
    {

    }
}

注册导航视图

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public class ModuleAModule : IModule
{
    public void OnInitialized(IContainerProvider containerProvider)
    {
        
    }

    public void RegisterTypes(IContainerRegistry containerRegistry)
    {
        containerRegistry.RegisterForNavigation<ViewA>();
        containerRegistry.RegisterForNavigation<ViewB>();
    }
}

public partial class App : PrismApplication
{
    protected override Window CreateShell()
    {
        return Container.Resolve<MainWindow>();
    }

    protected override void RegisterTypes(IContainerRegistry containerRegistry)
    {
        
    }

    protected override void ConfigureModuleCatalog(IModuleCatalog moduleCatalog)
    {
        moduleCatalog.AddModule<ModuleA.ModuleAModule>();
    }
}

导航视图

MainWindow.xaml

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<Window x:Class="BasicRegionNavigation.Views.MainWindow"
        xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
        xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
        xmlns:prism="http://prismlibrary.com/"
        prism:ViewModelLocator.AutoWireViewModel="True"
        Title="{Binding Title}" Height="350" Width="525">
    <DockPanel LastChildFill="True">
        <StackPanel Orientation="Horizontal" DockPanel.Dock="Top" Margin="5" >
            <Button Command="{Binding NavigateCommand}" CommandParameter="ViewA" Margin="5">Navigate to View A</Button>
            <Button Command="{Binding NavigateCommand}" CommandParameter="ViewB" Margin="5">Navigate to View B</Button>
        </StackPanel>
        <ContentControl prism:RegionManager.RegionName="ContentRegion" Margin="5"  />
    </DockPanel>
</Window>

MainWindowViewModel.cs

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public class MainWindowViewModel : BindableBase
{
    private readonly IRegionManager _regionManager;

    private string _title = "Prism Unity Application";
    public string Title
    {
        get { return _title; }
        set { SetProperty(ref _title, value); }
    }

    public DelegateCommand<string> NavigateCommand { get; private set; }

    public MainWindowViewModel(IRegionManager regionManager)
    {
        _regionManager = regionManager;

        NavigateCommand = new DelegateCommand<string>(Navigate);
    }

    private void Navigate(string navigatePath)
    {
        if (navigatePath != null)
            _regionManager.RequestNavigate("ContentRegion", navigatePath);
    }
}

导航视图请求回调

MainWindowViewModel.cs

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public class MainWindowViewModel : BindableBase
{
    private readonly IRegionManager _regionManager;

    private string _title = "Prism Unity Application";
    public string Title
    {
        get { return _title; }
        set { SetProperty(ref _title, value); }
    }

    public DelegateCommand<string> NavigateCommand { get; private set; }

    public MainWindowViewModel(IRegionManager regionManager)
    {
        _regionManager = regionManager;

        NavigateCommand = new DelegateCommand<string>(Navigate);
    }

    private void Navigate(string navigatePath)
    {
        if (navigatePath != null)
            // _regionManager.RequestNavigate("ContentRegion", navigatePath);
            _regionManager.RequestNavigate("ContentRegion", navigatePath, NavigationComplete);
    }
	
    /// <summary>
    /// 导航请求回调方法
    /// </summary>
    /// <param name="result">导航结果</param>
    private void NavigationComplete(NavigationResult result)
    {
        System.Windows.MessageBox.Show(String.Format("Navigation to {0} complete. ", result.Context.Uri));
    }
}

视图察觉参与导航

ViewA/B.xaml

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<UserControl x:Class="ModuleA.Views.ViewA"
             xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
             xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
             xmlns:prism="http://prismlibrary.com/"             
             prism:ViewModelLocator.AutoWireViewModel="True">
    <StackPanel>
        <TextBlock Text="{Binding Title}" FontSize="48" HorizontalAlignment="Center" VerticalAlignment="Center" />
        <TextBlock Text="{Binding PageViews}" FontSize="24" HorizontalAlignment="Center" VerticalAlignment="Center"/>
    </StackPanel>
</UserControl>

ViewA/BViewModel.cs

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public class ViewAViewModel : BindableBase, INavigationAware
{
    private string _title = "ViewA";
    public string Title
    {
        get { return _title; }
        set { SetProperty(ref _title, value); }
    }

    private int _pageViews;
    public int PageViews
    {
        get { return _pageViews; }
        set { SetProperty(ref _pageViews, value); }
    }

    public ViewAViewModel()
    {

    }

    /// <summary>
    /// 当实现者被导航到时调用。
    /// </summary>
    /// <param name="navigationContext">导航上下文</param>
    public void OnNavigatedTo(NavigationContext navigationContext)
    {
        PageViews++;
    }

    /// <summary>
    /// 调用以确定此实例是否可以处理导航请求。
    /// </summary>
    /// <param name="navigationContext">导航上下文</param>
    /// <returns>如果这个实例接受导航请求，返回True;否则,False（将会导航至此视图的新实例）</returns>
    public bool IsNavigationTarget(NavigationContext navigationContext)
    {
        return true;
    }

    /// <summary>
    /// 当实现者被导航离开时调用。
    /// </summary>
    /// <param name="navigationContext">导航上下文</param>
    public void OnNavigatedFrom(NavigationContext navigationContext)
    {

    }
}

通过参数导航

Model

Person.cs

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public class Person : INotifyPropertyChanged
{
    #region Properties

    private string _firstName;
    public string FirstName
    {
        get { return _firstName; }
        set
        {
            _firstName = value;
            OnPropertyChanged();
        }
    }

    private string _lastName;
    public string LastName
    {
        get { return _lastName; }
        set
        {
            _lastName = value;
            OnPropertyChanged();
        }
    }

    private int _age;
    public int Age
    {
        get { return _age; }
        set
        {
            _age = value;
            OnPropertyChanged();
        }
    }

    private DateTime? _lastUpdated;
    public DateTime? LastUpdated
    {
        get { return _lastUpdated; }
        set
        {
            _lastUpdated = value;
            OnPropertyChanged();
        }
    }

    #endregion //Properties

    #region INotifyPropertyChanged

    public event PropertyChangedEventHandler PropertyChanged;
    protected void OnPropertyChanged([CallerMemberName]string propertyname = null)
    {
        PropertyChanged?.Invoke(this, new PropertyChangedEventArgs(propertyname));
    }

    #endregion //INotifyPropertyChanged

    public override string ToString()
    {
        return String.Format("{0}, {1}", LastName, FirstName);
    }
}

View

PersonList.xaml

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<UserControl
    x:Class="ModuleA.Views.PersonList"
    xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
    xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
    xmlns:i="http://schemas.microsoft.com/xaml/behaviors"
    xmlns:prism="http://prismlibrary.com/"
    prism:ViewModelLocator.AutoWireViewModel="True">

    <UserControl.Resources>
        <Style TargetType="TabItem">
            <Setter Property="Header" Value="{Binding DataContext.SelectedPerson.FirstName}" />
        </Style>
    </UserControl.Resources>

    <Grid
        x:Name="LayoutRoot"
        Margin="10"
        Background="White">
        <Grid.RowDefinitions>
            <RowDefinition Height="100" />
            <RowDefinition Height="Auto" />
        </Grid.RowDefinitions>

        <ListBox x:Name="_listOfPeople" ItemsSource="{Binding People}">
            <i:Interaction.Triggers>
                <i:EventTrigger EventName="SelectionChanged">
                    <prism:InvokeCommandAction Command="{Binding PersonSelectedCommand}" CommandParameter="{Binding SelectedItem, ElementName=_listOfPeople}" />
                </i:EventTrigger>
            </i:Interaction.Triggers>
        </ListBox>
        <TabControl
            Grid.Row="1"
            Margin="10"
            prism:RegionManager.RegionName="PersonDetailsRegion" />
    </Grid>
</UserControl>

PersonDetail.xaml

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<UserControl x:Class="ModuleA.Views.PersonDetail"
             xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
             xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
             xmlns:prism="http://prismlibrary.com/"             
             prism:ViewModelLocator.AutoWireViewModel="True">
    <Grid x:Name="LayoutRoot" Background="White">
        <Grid.ColumnDefinitions>
            <ColumnDefinition Width="Auto"/>
            <ColumnDefinition />
        </Grid.ColumnDefinitions>
        <Grid.RowDefinitions>
            <RowDefinition Height="Auto"/>
            <RowDefinition Height="Auto"/>
            <RowDefinition Height="Auto"/>
        </Grid.RowDefinitions>

        <!-- First Name -->
        <TextBlock Text="First Name:" Margin="5" />
        <TextBlock Grid.Column="1" Margin="5" Text="{Binding SelectedPerson.FirstName}" />

        <!-- Last Name -->
        <TextBlock Grid.Row="1" Text="Last Name:" Margin="5" />
        <TextBlock Grid.Row="1" Grid.Column="1"  Margin="5" Text="{Binding SelectedPerson.LastName}" />

        <!-- Age -->
        <TextBlock Grid.Row="2" Text="Age:" Margin="5"/>
        <TextBlock Grid.Row="2" Grid.Column="1"  Margin="5" Text="{Binding SelectedPerson.Age}"/>
    </Grid>
</UserControl>

ViewModel

PersonListViewModel.cs

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using System;
using ModuleA.Business;
using Prism.Mvvm;
using Prism.Navigation.Regions;

namespace ModuleA.ViewModels
{
    public class PersonDetailViewModel : BindableBase, INavigationAware
    {
        private Person _selectedPerson;
        public Person SelectedPerson
        {
            get { return _selectedPerson; }
            set { SetProperty(ref _selectedPerson, value); }
        }

        public PersonDetailViewModel()
        {

        }

        public void OnNavigatedTo(NavigationContext navigationContext)
        {
            var person = navigationContext.Parameters["person"] as Person;
            if (person != null)
                SelectedPerson = person;
        }

        public bool IsNavigationTarget(NavigationContext navigationContext)
        {
            var person = navigationContext.Parameters["person"] as Person;
            if (person != null)
                return SelectedPerson != null && SelectedPerson.LastName == person.LastName;
            else
                return true;
        }

        public void OnNavigatedFrom(NavigationContext navigationContext)
        {

        }
    }
}

PersonDetailViewModel.cs

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using ModuleA.Business;
using Prism.Commands;
using Prism.Mvvm;
using Prism.Navigation.Regions;
using System;
using System.Collections.ObjectModel;

namespace ModuleA.ViewModels
{
    public class PersonListViewModel : BindableBase
    {
        IRegionManager _regionManager;

        private ObservableCollection<Person> _people;
        public ObservableCollection<Person> People
        {
            get { return _people; }
            set { SetProperty(ref _people, value); }
        }

        public DelegateCommand<Person> PersonSelectedCommand { get; private set; }

        public PersonListViewModel(IRegionManager regionManager)
        {
            _regionManager = regionManager;

            PersonSelectedCommand = new DelegateCommand<Person>(PersonSelected);
            CreatePeople();
        }

        private void PersonSelected(Person person)
        {
            var parameters = new NavigationParameters();
            parameters.Add("person", person);

            if (person != null)
                __regionManager.RequestNavigate("PersonDetailsRegion", typeof(PersonDetail).Name, parameters);
        }

        private void CreatePeople()
        {
            var people = new ObservableCollection<Person>();
            for (int i = 0; i < 10; i++)
            {
                people.Add(new Person()
                {
                    FirstName = String.Format("First {0}", i),
                    LastName = String.Format("Last {0}", i),
                    Age = i
                });
            }

            People = people;
        }
    }
}

导航请求处理

ViewA/BViewModel.cs

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public class ViewAViewModel : BindableBase, IConfirmNavigationRequest
{
    public ViewAViewModel()
    {

    }

    /// <summary>
    /// 确定此实例是否接受导航。
    /// </summary>
    /// <param name="navigationContext">导航上下文</param>
    /// <param name="continuationCallback">指示导航何时可以继续的回调函数。</param>
    /// <remarks>
    /// 此方法的实现者在此方法完成之前不需要调用回调函数，但它们必须确保回调函数最终被调用。
    /// </remarks>
    public void ConfirmNavigationRequest(NavigationContext navigationContext, Action<bool> continuationCallback)
    {
        bool result = true;

        if (MessageBox.Show("Do you to navigate?", "Navigate?", MessageBoxButton.YesNo) == MessageBoxResult.No)
            result = false;

        continuationCallback(result);
    }

    public bool IsNavigationTarget(NavigationContext navigationContext)
    {
        return true;
    }

    public void OnNavigatedFrom(NavigationContext navigationContext)
    {
        
    }

    public void OnNavigatedTo(NavigationContext navigationContext)
    {
        
    }
}