netcore2.1 在后台运行一个任务

 1 namespace Microsoft.Extensions.Hosting
 2 {
 3     //
 4     // 摘要:
 5     //     Base class for implementing a long running Microsoft.Extensions.Hosting.IHostedService.
 6     public abstract class BackgroundService : IHostedService, IDisposable
 7     {
 8         protected BackgroundService();
 9 
10         public virtual void Dispose();
11         //
12         // 摘要:
13         //     Triggered when the application host is ready to start the service.
14         //
15         // 参数:
16         //   cancellationToken:
17         //     Indicates that the start process has been aborted.
18         public virtual Task StartAsync(CancellationToken cancellationToken);
19         //
20         // 摘要:
21         //     Triggered when the application host is performing a graceful shutdown.
22         //
23         // 参数:
24         //   cancellationToken:
25         //     Indicates that the shutdown process should no longer be graceful.
26         [AsyncStateMachine(typeof(<StopAsync>d__4))]
27         public virtual Task StopAsync(CancellationToken cancellationToken);
28         //
29         // 摘要:
30         //     This method is called when the Microsoft.Extensions.Hosting.IHostedService starts.
31         //     The implementation should return a task that represents the lifetime of the long
32         //     running operation(s) being performed.
33         //
34         // 参数:
35         //   stoppingToken:
36         //     Triggered when Microsoft.Extensions.Hosting.IHostedService.StopAsync(System.Threading.CancellationToken)
37         //     is called.
38         //
39         // 返回结果:
40         //     A System.Threading.Tasks.Task that represents the long running operations.
41         protected abstract Task ExecuteAsync(CancellationToken stoppingToken);
42     }
43 }

 1 internal class TokenRefreshService : BackgroundService
 2     {
 3         private readonly ILogger _logger;
 4 
 5         public TokenRefreshService(ILogger<TokenRefresh2Service> logger)
 6         {
 7             _logger = logger;
 8         }
 9 
10         protected override async Task ExecuteAsync(CancellationToken stoppingToken)
11         {
12             _logger.LogInformation("Service starting");
13 
14             while (!stoppingToken.IsCancellationRequested)
15             {
16                 _logger.LogInformation(DateTime.Now.ToLongTimeString() + ": Refresh Token!");//在此写需要执行的任务
17                 await Task.Delay(5000, stoppingToken);
18             }
19 
20             _logger.LogInformation("Service stopping");
21         }
22     }

 1  // This method gets called by the runtime. Use this method to add services to the container.
 2         public void ConfigureServices(IServiceCollection services)
 3         {
 4             services.Configure<CookiePolicyOptions>(options =>
 5             {
 6                 // This lambda determines whether user consent for non-essential cookies is needed for a given request.
 7                 options.CheckConsentNeeded = context => true;
 8                 options.MinimumSameSitePolicy = SameSiteMode.None;
 9             });
10 
11 
12             services.AddMvc().SetCompatibilityVersion(CompatibilityVersion.Version_2_1);
13 
14 
15             services.AddSingleton<Microsoft.Extensions.Hosting.IHostedService, TokenRefreshService>();
16 
17 
18 
19         }