WPF/Silverlight 雖強大於 UI 表現，但無法解決大型專案的可維護性難題。Microsoft Patterns & Practices 團隊推出 WPF Composite Application Guidance (Prism)，提供模組化、區域管理、命令、事件聚合等核心服務，協助建構鬆散耦合、可獨立開發/測試/部署的複合應用程式。本文系統解析 Prism 4 大核心概念：Bootstrapper/Container、Module 初始化、Region/RegionManager、View/Presentation Model/Command/EventAggregator。
| 概念 | 說明 |
|---|---|
| Module | 功能垂直切片，含 View、ViewModel、Service，獨立組件 |
| Shell | 主視窗宿主，定義 Region，不包含具體業務邏輯 |
| Region | UI 佔位符（ContentControl/ItemsControl/Selector），Module 在運行時注入 View |
| Service | 跨模組共用功能（Logger、EventAggregator、ModuleLoader 等），透過 Container 管理 |
public class StockTraderRIBootstrapper : UnityBootstrapper
{
private readonly EntLibLoggerAdapter _logger = new EntLibLoggerAdapter();
protected override IModuleEnumerator GetModuleEnumerator()
{
return new StaticModuleEnumerator()
.AddModule(typeof(NewsModule))
.AddModule(typeof(MarketModule))
.AddModule(typeof(WatchModule), "MarketModule")
.AddModule(typeof(PositionModule), "MarketModule", "NewsModule");
}
protected override ILoggerFacade LoggerFacade => _logger;
protected override void ConfigureContainer()
{
Container.RegisterType<IShellView, Shell>();
base.ConfigureContainer();
}
protected override DependencyObject CreateShell()
{
var presenter = Container.Resolve<ShellPresenter>();
var view = presenter.View;
view.ShowView();
return view as DependencyObject;
}
}public interface IModule { void Initialize(); }
public class WatchModule : IModule
{
private readonly IUnityContainer _container;
private readonly IRegionManager _regionManager;
public WatchModule(IUnityContainer container, IRegionManager regionManager)
{
_container = container;
_regionManager = regionManager;
}
public void Initialize()
{
RegisterViewsAndServices();
var watchListPM = _container.Resolve<IWatchListPresentationModel>();
_regionManager.Regions["WatchRegion"].Add(watchListPM.View);
var addWatchPresenter = _container.Resolve<IAddWatchPresenter>();
_regionManager.Regions["MainToolbarRegion"].Add(addWatchPresenter.View);
}
private void RegisterViewsAndServices()
{
_container.RegisterType<IWatchListService, WatchListService>(new ContainerControlledLifetimeManager());
_container.RegisterType<IWatchListView, WatchListView>();
_container.RegisterType<IWatchListPresentationModel, WatchListPresentationModel>();
_container.RegisterType<IAddWatchView, AddWatchView>();
_container.RegisterType<IAddWatchPresenter, AddWatchPresenter>();
}
}
<ItemsControl Grid.Row="1" Grid.Column="1" x:Name="MainToolbar"
cal:RegionManager.RegionName="MainToolbarRegion">
<ItemsControl.ItemsPanel>
<ItemsPanelTemplate><WrapPanel /></ItemsPanelTemplate>
</ItemsControl.ItemsPanel>
</ItemsControl>| 模式 | 核心 | 適用 |
|---|---|---|
| Presentation Model | Model 擁有 UI 狀態與行為，View 純繫結渲染 | WPF 資料繫結/樣板/命令豐富時 |
| Supervising Controller | Presenter 處理 UI 邏輯，View 委派並回呼簡單操作 | 需精細控制 UI 元素啟用/顯示時 |
public class PositionSummaryPresentationModel : IPositionSummaryPresentationModel, INotifyPropertyChanged
{
public PositionSummaryPresentationModel(IPositionSummaryView view, ...) { ... }
public IPositionSummaryView View { get; set; }
public ObservableCollection<PositionSummaryItem> PositionSummaryItems { get; set; }
}
public class TrendLinePresenter : ITrendLinePresenter
{
private readonly IMarketHistoryService _service;
public TrendLinePresenter(ITrendLineView view, IMarketHistoryService service) { ... }
public ITrendLineView View { get; set; }
public void OnTickerSymbolSelected(string symbol)
{
var history = _service.GetPriceHistory(symbol);
View.UpdateLineChart(history);
View.SetChartTitle(symbol);
}
}
public class WatchListService
{
public ObservableCollection<string> WatchItems { get; }
public DelegateCommand<string> AddWatchCommand { get; }
public WatchListService(IMarketFeedService feed)
{
WatchItems = new ObservableCollection<string>();
AddWatchCommand = new DelegateCommand<string>(AddWatch);
}
private void AddWatch(string symbol)
{
WatchItems.Add(symbol);
// 呼叫服務...
}
}
// 定義事件（共用組件）
public class TickerSymbolSelectedEvent : CompositeWpfEvent<string> { }
// 發布者：PositionSummaryPresentationModel
private void View_TickerSymbolSelected(object sender, DataEventArgs<string> e)
{
_trendLinePresenter.OnTickerSymbolSelected(e.Value);
EventAggregator.GetEvent<TickerSymbolSelectedEvent>().Publish(e.Value);
}
// 訂閱者：NewsController
public void Run()
{
regionManager.Regions["NewsRegion"].Add(articlePM.View);
EventAggregator.GetEvent<TickerSymbolSelectedEvent>()
.Subscribe(ShowNews, ThreadOption.UIThread);
}
public void ShowNews(string symbol) => articlePM.SetTickerSymbol(symbol);掌握 Prism 四大支柱——Bootstrapper/Container、Module/Region、View/Presentation Pattern、Command/EventAggregator，即能駕馭企業級 WPF 複合應用程式架構。
