MyAvaloniaDemo/AuroraDesk.Presentation/Services/PageViewModelFactory.cs

using AuroraDesk.Core.Interfaces;
using AuroraDesk.Presentation.ViewModels.Base;
using AuroraDesk.Presentation.ViewModels.Pages;
using Microsoft.Extensions.DependencyInjection;
using Microsoft.Extensions.Logging;
using ReactiveUI;
using System;

namespace AuroraDesk.Presentation.Services;

/// <summary>
/// PageViewModel 工厂实现
/// </summary>
public class PageViewModelFactory : IPageViewModelFactory
{
    private readonly IServiceProvider _serviceProvider;

    public PageViewModelFactory(IServiceProvider serviceProvider)
    {
        _serviceProvider = serviceProvider;
    }

    public T CreatePageViewModel<T>(IScreen screen) where T : IRoutableViewModel
    {
        // 尝试从服务容器中获取已注册的 ViewModel
        // 如果未注册，则使用反射创建实例
        try
        {
            return _serviceProvider.GetService<T>() ?? 
                   (T)Activator.CreateInstance(typeof(T), screen)!;
        }
        catch
        {
            // 如果服务容器中没有且反射失败，尝试使用 ActivatorUtilities
            return ActivatorUtilities.CreateInstance<T>(_serviceProvider, screen);
        }
    }

    public IRoutableViewModel CreatePageViewModel(string pageId, IScreen screen)
    {
        return pageId switch
        {
            "dashboard" => CreatePageViewModel<DashboardPageViewModel>(screen),
            "users" => CreatePageViewModel<UsersPageViewModel>(screen),
            "users-list" => CreatePageViewModel<UsersPageViewModel>(screen),
            "users-roles" => CreatePageViewModel<UsersPageViewModel>(screen),
            "users-permissions" => CreatePageViewModel<UsersPageViewModel>(screen),
            "settings" => CreatePageViewModel<SettingsPageViewModel>(screen),
            "settings-general" => CreatePageViewModel<SettingsPageViewModel>(screen),
            "settings-security" => CreatePageViewModel<SettingsPageViewModel>(screen),
            "settings-backup" => CreatePageViewModel<SettingsPageViewModel>(screen),
            "reports" => CreatePageViewModel<ReportsPageViewModel>(screen),
            "help" => CreatePageViewModel<HelpPageViewModel>(screen),
            "dialog-host" => CreatePageViewModel<DialogHostPageViewModel>(screen),
            "icons" => CreateIconsPageViewModel(screen),
            "editor" => CreateEditorPageViewModel(screen),
            _ => throw new ArgumentException($"Unknown page: {pageId}", nameof(pageId))
        };
    }

    private IconsPageViewModel CreateIconsPageViewModel(IScreen screen)
    {
        // ActivatorUtilities 会自动解析所有依赖（IIconService, ILogger）
        return ActivatorUtilities.CreateInstance<IconsPageViewModel>(_serviceProvider, screen);
    }

    private EditorPageViewModel CreateEditorPageViewModel(IScreen screen)
    {
        var logger = _serviceProvider.GetService<Microsoft.Extensions.Logging.ILogger<EditorPageViewModel>>();
        return ActivatorUtilities.CreateInstance<EditorPageViewModel>(_serviceProvider, screen, logger ?? Microsoft.Extensions.Logging.Abstractions.NullLogger<EditorPageViewModel>.Instance);
    }
}