如何确保在aspnetcore后台服务中启动的进程在web应用程序退出时终止。

Question

我做了一个后台服务，在aspnet核心web上开发时运行。

public class VueService : BackgroundService
    {
        private readonly Microsoft.Extensions.Hosting.IHostingEnvironment hostingEnvironment;
        private readonly ILogger<VueService> logger;

        public VueService(Microsoft.Extensions.Hosting.IHostingEnvironment hostingEnvironment, ILogger<VueService> logger)
        {
            this.hostingEnvironment = hostingEnvironment;
            this.logger = logger ?? throw new ArgumentNullException(nameof(logger));
        }
        protected override async Task ExecuteAsync(CancellationToken stoppingToken)
        {
            System.Diagnostics.Process process = new System.Diagnostics.Process()
            {
                EnableRaisingEvents = true
            };

            try
            {

                System.Diagnostics.ProcessStartInfo startInfo = new System.Diagnostics.ProcessStartInfo();
                // startInfo.WindowStyle = System.Diagnostics.ProcessWindowStyle.Hidden;
                startInfo.FileName = "cmd.exe";
                startInfo.Arguments = "/C npm run serve";
                startInfo.WorkingDirectory = hostingEnvironment.ContentRootPath;
                process.StartInfo = startInfo;

                // redirect the output
                process.StartInfo.RedirectStandardOutput = true;
                process.StartInfo.RedirectStandardError = true;
                // hookup the eventhandlers to capture the data that is received
                process.OutputDataReceived += (sender, args) => logger.LogInformation(args.Data);
                process.ErrorDataReceived += (sender, args) => logger.LogError(args.Data);




                // direct start
                process.StartInfo.UseShellExecute = false;

                process.Start();

                // start our event pumps
                process.BeginOutputReadLine();
                process.BeginErrorReadLine();


                while (!stoppingToken.IsCancellationRequested)
                {
                    await Task.Delay(1000);
                }

            }catch(Exception ex)
            {

            }
            finally
            {
                try
                {
                    process.Kill();
                }
                catch (Exception)
                {

                }
            }
        }
    }

当应用程序停止/调试结束时，我如何确保它不会挂起？

Answer 1

如果您的后台服务是nodejs服务，请在您的启动类中尝试这样做

//ConfigureServices
services.AddNodeServices(node => node.ProjectPath = Path.GetFullPath("path/to/nodejs/project"));

//Configure
app.UseSpa(spa =>
{
    app.ApplicationServices.GetRequiredService<INodeServices>().InvokeAsync<object>("path/to/your/entry.js");
    spa.UseProxyToSpaDevelopmentServer("http://localhost:3000"); //remove it if you don't need asp.net core application to proxy for your background service
});

它可以正确地终止nodejs服务，即使在被终止的web应用程序上也是如此。

Answer 2

ASP.NET Core hosted services (包括BackgroundService实例)在进程内运行。当进程退出时，它们将被终止。