ASP.NET核心.NET 6预览版7 Windows服务

Question

我用Visual Studio2022预览版创建了一个新的Windows项目，并尝试将其作为ASP.NET服务运行。我下载了最新的Microsoft.Extensions.Hosting.WindowsServices包(6.0.0-preview.7.21377.19)。

在进行在线搜索时，函数.UseWindowsService()进入CreateHostBuilder方法。但在新的模板中，它看起来不同。我不明白在新模板中应该在哪里调用.UseWindowsService。这是我当前的代码，看起来服务正在启动，但是当我浏览到localhost:5000时，它给出了404错误

using Microsoft.OpenApi.Models;
using Microsoft.Extensions.Hosting.WindowsServices;

var builder = WebApplication.CreateBuilder(args);

builder.Host.UseWindowsService(); // <--- Added this line

// Add services to the container.

builder.Services.AddControllers();
builder.Services.AddSwaggerGen(c =>
{
    c.SwaggerDoc("v1", new() { Title = "MyWindowsService", Version = "v1" });
});

var app = builder.Build();

// Configure the HTTP request pipeline.
if (builder.Environment.IsDevelopment())
{
    app.UseDeveloperExceptionPage();
        app.UseSwagger();
    app.UseSwaggerUI(c => c.SwaggerEndpoint("/swagger/v1/swagger.json", "MyWindowsService v1"));
}

app.UseAuthorization();

app.MapControllers();


app.Run();

我像这样发布了我的服务exe

dotnet publish -c Release -r win-x64 --self-contained

Answer 1

因为简单地使用

builder.Host.UseWindowsService();

不能与WebApplication.CreateBuilder() (see)一起使用，而是会抛出异常

Exception Info: System.NotSupportedException: The content root changed from "C:\Windows\system32\" to "...". Changing the host configuration using WebApplicationBuilder.Host is not supported. Use WebApplication.CreateBuilder(WebApplicationOptions) instead.

或者更确切地说，将导致此错误

Start-Service : Service 'Service1 (Service1)' cannot be started due to the following error: Cannot start service Service1 on computer '.'.

尝试在PowerShell中使用 start - Service 启动服务时，我发现了一种适用于我的解决方法

using Microsoft.Extensions.Hosting.WindowsServices;

var options = new WebApplicationOptions
{
    Args = args,
    ContentRootPath = WindowsServiceHelpers.IsWindowsService() ? AppContext.BaseDirectory : default
};

var builder = WebApplication.CreateBuilder(options);

builder.Host.UseWindowsService();

这里：An asp.net core web api application, using "UseWindowsService", reports an error “System.NotSupportedException: The content root changed. Changing the host configuration is not supported ” when starting the service

Answer 2

以下代码将生存期设置为WindowsServiceLifetime并启用到事件日志的日志记录。在大多数情况下，这应该是您将应用程序作为Windows服务运行所需的全部内容。

if (WindowsServiceHelpers.IsWindowsService())
{
    appBuilder.Services.AddSingleton<IHostLifetime, WindowsServiceLifetime>();
    appBuilder.Logging.AddEventLog(settings =>
    {
        if (string.IsNullOrEmpty(settings.SourceName))
        {
            settings.SourceName = appBuilder.Environment.ApplicationName;
        }
    });
}