MyAvaloniaDemo/App.axaml.cs

using Avalonia;
using Avalonia.Controls.ApplicationLifetimes;
using Avalonia.Markup.Xaml;
using Microsoft.Extensions.Configuration;
using Microsoft.Extensions.DependencyInjection;
using Microsoft.Extensions.Hosting;
using Microsoft.Extensions.Logging;
using MyAvaloniaApp.Configuration;
using MyAvaloniaApp.Extensions;
using ReactiveUI;
using Splat;
using System;
using System.IO;

namespace MyAvaloniaApp;

public partial class App : Application
{
    private IServiceProvider? _serviceProvider;
    private ILogger<App>? _logger;

    /// <summary>
    /// 无参构造函数，用于 Avalonia 框架初始化
    /// </summary>
    public App()
    {
    }

    public override void Initialize()
    {
        AvaloniaXamlLoader.Load(this);
        
        // 注册自定义 ViewLocator
        Locator.CurrentMutable.RegisterConstant(new Views.ViewLocator(), typeof(IViewLocator));
    }

    public override void OnFrameworkInitializationCompleted()
    {
        // 在框架初始化完成后创建和配置 HostBuilder
        var host = CreateHostBuilder().Build();
        _serviceProvider = host.Services;
        _logger = _serviceProvider.GetRequiredService<ILogger<App>>();
        
        _logger.LogInformation("App 框架初始化完成，HostBuilder 已创建并配置");

        if (ApplicationLifetime is IClassicDesktopStyleApplicationLifetime desktop)
        {
            _logger.LogInformation("使用依赖注入创建 MainWindow");
            desktop.MainWindow = _serviceProvider.GetRequiredService<MainWindow>();
        }

        base.OnFrameworkInitializationCompleted();
        _logger.LogInformation("框架初始化完成");
    }

    /// <summary>
    /// 创建 HostBuilder
    /// </summary>
    /// <returns>HostBuilder</returns>
    private IHostBuilder CreateHostBuilder() =>
        Host.CreateDefaultBuilder()
            .ConfigureAppConfiguration((context, config) =>
            {
                // 配置应用程序设置
                config.SetBasePath(Directory.GetCurrentDirectory())
                      .AddJsonFile("appsettings.json", optional: false, reloadOnChange: true)
                      .AddJsonFile($"appsettings.{context.HostingEnvironment.EnvironmentName}.json", optional: true)
                      .AddEnvironmentVariables();
            })
            .ConfigureLogging((context, logging) =>
            {
                // 配置日志
                logging.ClearProviders();
                logging.AddConfiguration(context.Configuration.GetSection("Logging"));
                // 启用控制台日志以便调试
                logging.AddConsole();
                logging.AddDebug();
            })
            .ConfigureServices((context, services) =>
            {
                // 注册配置
                services.Configure<AppSettings>(context.Configuration.GetSection("AppSettings"));
                
                // 注册业务服务
                services.AddBusinessServices();
                
                // 注册 ViewModel
                services.AddViewModels();
                
                // 注册 ReactiveUI 服务
                services.AddReactiveUI();
                
                // 注册 Avalonia 应用程序
                services.AddTransient<MainWindow>();
            });
}