Prism（六） 事件聚合器

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

事件聚合器

bandicam 2024-03-04 16-12-40-606

事件发布模块

MessageView.xaml

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<UserControl x:Class="ModuleA.Views.MessageView"
             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" Padding="25">
    <StackPanel>
        <TextBox Text="{Binding Message}" Margin="5"/>
        <Button Command="{Binding SendMessageCommand}" Content="Send Message" Margin="5"/>
    </StackPanel>
</UserControl>

MessageViewModel.cs

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public class MessageViewModel : BindableBase
{
    IEventAggregator _ea;

    private string _message = "Message to Send";
    public string Message
    {
        get { return _message; }
        set { SetProperty(ref _message, value); }
    }

    public DelegateCommand SendMessageCommand { get; private set; }

    public MessageViewModel(IEventAggregator ea)
    {
        _ea = ea;
        SendMessageCommand = new DelegateCommand(SendMessage);
    }

    private void SendMessage()
    {
        _ea.GetEvent<MessageSentEvent>().Publish(Message);
    }
}

ModuleAModule.cs

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public class ModuleAModule : IModule
{
    public void OnInitialized(IContainerProvider containerProvider)
    {
        var regionManager = containerProvider.Resolve<IRegionManager>();
        regionManager.RegisterViewWithRegion("LeftRegion", typeof(MessageView));
    }

    public void RegisterTypes(IContainerRegistry containerRegistry)
    {
        
    }
}

事件订阅模块

MessageList.xaml

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<UserControl x:Class="ModuleB.Views.MessageList"
             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" Padding="25">
    <Grid>
        <ListBox ItemsSource="{Binding Messages}" />
    </Grid>
</UserControl>

MessageListViewModel.cs

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public class MessageListViewModel : BindableBase
{
    IEventAggregator _ea;

    private ObservableCollection<string> _messages;
    public ObservableCollection<string> Messages
    {
        get { return _messages; }
        set { SetProperty(ref _messages, value); }
    }

    public MessageListViewModel(IEventAggregator ea)
    {
        _ea = ea;
        Messages = new ObservableCollection<string>();

        _ea.GetEvent<MessageSentEvent>().Subscribe(MessageReceived);
    }

    private void MessageReceived(string message)
    {
        Messages.Add(message);
    }
}

ModuleBModule.cs

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public class ModuleBModule : IModule
{
    public void OnInitialized(IContainerProvider containerProvider)
    {
        var regionManager = containerProvider.Resolve<IRegionManager>();
        regionManager.RegisterViewWithRegion("RightRegion", typeof(MessageList));
    }

    public void RegisterTypes(IContainerRegistry containerRegistry)
    {

    }
}

信息发送事件

MessageSentEvent.cs

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public class MessageSentEvent : PubSubEvent<string>
{
}

主程序

MainWindow.xaml

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<Window x:Class="UsingEventAggregator.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">
    <Grid>
        <Grid.ColumnDefinitions>
            <ColumnDefinition />
            <ColumnDefinition />
        </Grid.ColumnDefinitions>
        <ContentControl prism:RegionManager.RegionName="LeftRegion" />
        <ContentControl Grid.Column="1" prism:RegionManager.RegionName="RightRegion" />
    </Grid>
</Window>

App.xaml.cs

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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>();
        moduleCatalog.AddModule<ModuleB.ModuleBModule>();
    }
}

事件聚合器扩展：订阅事件过滤

bandicam 2024-03-04 16-21-14-118

事件订阅模块

MessageListViewModel.cs

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public class MessageListViewModel : BindableBase
{
    IEventAggregator _ea;

    private ObservableCollection<string> _messages;
    public ObservableCollection<string> Messages
    {
        get { return _messages; }
        set { SetProperty(ref _messages, value); }
    }

    public MessageListViewModel(IEventAggregator ea)
    {
        _ea = ea;
        Messages = new ObservableCollection<string>();

        // _ea.GetEvent<MessageSentEvent>().Subscribe(MessageReceived);
        _ea.GetEvent<MessageSentEvent>().Subscribe(MessageReceived, ThreadOption.PublisherThread, false, (msg) => msg.StartsWith("Zhy"));
    }

    private void MessageReceived(string message)
    {
        Messages.Add(message);
    }
}