如何在ASP.NET Web.Api中运行后台任务？

Question

I'm developing an ASP.NET MVC Web Api 2 app with C# and .NET Framework 4.5.1.

Sometimes, when user calls a get on an ApiController I have to run a task in background. The task will fill up a database table with more data.

Searching on Internet I have found this article, How to run Background Tasks in ASP.NET . And I want to use HangFire . But reading its documentation I haven't found a way to use it without using OWIN on my ASP.NET Web Api app (I'm not using it right now).

Is there a way to use Hangfire without OWIN? or maybe, is there another option to run background tasks on an ASP.NET Web Api 2 app?

Answer 1

I'm not too sure if you still need this (I doubt it) but I'll just answer this question since it was ranking high on Google Search. Well, the conventional way to start the Hangfire server using OWIN is as follows...

public void Configuration(IAppBuilder app){
    app.UseHangfireServer();
}

Server Lifecycle

However, based on the documentation...Hangfire is not reliant on OWIN at all and all you need to do is start and stop the BackgroundJobServer

(Source) http://docs.hangfire.io/en/latest/background-processing/processing-background-jobs.html

Hangfire Server part is responsible for background job processing. The Server does not depend on ASP.NET and can be started anywhere, from a console application to Microsoft Azure Worker Role. Single API for all applications is exposed through the BackgroundJobServer class

That means you would start the server when the application starts...

var server = new BackgroundJobServer();

and you would dispose it when the application ends...

server.Dispose();

And that's exactly what app.UseHangfireServer(); does. See source code...

https://github.com/HangfireIO/Hangfire/blob/master/src/Hangfire.Core/AppBuilderExtensions.cs#L293

and

https://github.com/HangfireIO/Hangfire/blob/master/src/Hangfire.Core/AppBuilderExtensions.cs#L311

See example below using a global.asax..

    BackgroundJobServer _server;

    protected void Application_Start(object sender, EventArgs e)
    {
        GlobalConfiguration.Configuration
            .UseSqlServerStorage("YOUR_CONNECTION_STRING");

        _server = new BackgroundJobServer();
    }

    protected void Application_End(object sender, EventArgs e)
    {
        _server.Dispose();
    }

SQL Server Storage

To register the SQL Server Storage you don't need OWIN, this is all you need to do...

Hangfire.GlobalConfiguration.Configuration.UseSqlServerStorage("YOUR_CONNECTION_STRING");

Again, I came to that conclusion by looking at the source code here...

https://github.com/HangfireIO/Hangfire/blob/master/src/Hangfire.SqlServer/SqlServerStorageExtensions.cs

Conclusion

Hangfire does not rely on OWIN and they have acknowledged so

Answer 2

您可以使用ThreadPool.QueueUserWorkItem来委派您的进程，它将由CLR使用线程进行管理。