定期后台任务

本文介绍了定期后台任务的处理方法，对大家解决问题具有一定的参考价值，需要的朋友们下面随着小编来一起学习吧！ 问题描述

我刚开始尝试使用，而不是线程任务，我试图实现与每5分钟，只要对象是使用，但它不应该阻止垃圾运行的背景清理任务的对象集合。

粗制滥造的东西线沿线的（这显然是行不通的......）

公共类Foo：IDisposable接口{    私人CancellationTokenSource _tokenSource =新CancellationTokenSource（）;    公共美孚（）    {        清理（​​）;    }    公共无效的Dispose（）    {        _tokenSource.Cancel（）;    }    公共无效清除（）    {        Task.Delay（TimeSpan.FromSeconds（5），_tokenSource.Token）.ContinueWith（叔= GT;        {            //做工作            如果（！_tokenSource.IsCancellationRequested）            {                清理（​​）;            }        }，TaskContinuationOptions.NotOnCanceled）;    }}

什么是实施正确的方法是什么？

修改在回答I3arnon的问题，我使用了IDisposable，因为当我与对象完成，我希望它是垃圾回收。例如，没有f.Dispose（）以下（其中取消了任务，F没有出现被垃圾收集或清理任务取消。是否有实现更好的办法？

变种F =新的Foo（）;变种R =新的WeakReference（F）;Thread.sleep代码（TimeSpan.FromSeconds（15））;f.Dispose（）;F = NULL;System.GC.Collect（）;Thread.sleep代码（TimeSpan.FromSeconds（5））;Console.WriteLine（r.IsAlive）;

解决方案

是不够好？您也可以让这个类通过接受委托的，而内运行通用的，可重复使用。我真的不知道为什么你需要它是一个IDisposable接口，虽然...

公共类Foo：IDisposable接口{    私人CancellationTokenSource _tokenSource =新CancellationTokenSource（）;    公共美孚（）    {        Task.Run（异步（）=＆GT;等待CleanupAsync（））;    }    公共无效的Dispose（）    {        _tokenSource.Cancel（）;    }    公共异步任务CleanupAsync（）    {        而（！_tokenSource.Token.IsCancellationRequested）        {           //你需要的任何清理。           等待Task.Delay（TimeSpan.FormSeconds（5），_ tokenSource.Token）;        }    }}

的 Task.Run内的异步和等待可以被删除。他们只是在那里清晰度。 Task.Run（（）=＆GT; CleanupAsync（））;

I am just starting to try to use "Tasks" instead of Threads and am trying to implement an object with a background "cleanup" task that runs every 5 minutes as long as the object is in use but which should not block garbage collection.

Something crudely along the lines of (which obviously doesn't work...)

public class Foo : IDisposable { private CancellationTokenSource _tokenSource = new CancellationTokenSource(); public Foo() { Cleanup(); } public void Dispose() { _tokenSource.Cancel(); } public void Cleanup() { Task.Delay(TimeSpan.FromSeconds(5), _tokenSource.Token).ContinueWith(t => { //Do Work if (!_tokenSource.IsCancellationRequested) { Cleanup(); } }, TaskContinuationOptions.NotOnCanceled); } }

What is the correct way to implement?

EDIT In response to I3arnon's question, I am using IDisposable because when I am done with the object, I want it to be garbage collected. For example, without the f.Dispose() below (which cancels the task, f does not appear to be Garbage Collected, or the cleanup task canceled. Is there a better way to implement?

var f = new Foo(); var r = new WeakReference(f); Thread.Sleep(TimeSpan.FromSeconds(15)); f.Dispose(); f = null; System.GC.Collect(); Thread.Sleep(TimeSpan.FromSeconds(5)); Console.WriteLine(r.IsAlive);

解决方案

Is that good enough? You can also make this class generic and reusable by accepting a delegate to run inside the while. I'm not really sure why you need it to be an IDisposable though...

public class Foo : IDisposable { private CancellationTokenSource _tokenSource = new CancellationTokenSource(); public Foo() { Task.Run(async () => await CleanupAsync()); } public void Dispose() { _tokenSource.Cancel(); } public async Task CleanupAsync() { while (!_tokenSource.Token.IsCancellationRequested) { // Do whatever cleanup you need to. await Task.Delay(TimeSpan.FormSeconds(5),_tokenSource.Token); } } }

The async and await inside the Task.Run can be removed. They are just there for clarity. Task.Run(() => CleanupAsync());