C# · 12月 28, 2021

简单实现C#异步操作

在.net4.0以后异步操作,并行计算变得异常简单,但是由于公司项目开发基于.net3.5所以无法用到4.0的并行计算以及Task等异步编程。因此,为了以后更方便的进行异步方式的开发,我封装实现了异步编程框架,通过BeginInvoke、EndInvoke的方式实现异步编程。

一、框架结构

整个框架包括四个部分

1、基类抽象Opeartor
我把每个异步执行过程称为一个Operate,因此需要一个Opeartor去执行
2、FuncAsync
异步的Func
3、ActionAsync
异步的Action
4、Asynchorus
对ActionAsync和FuncAsync的封装

Operator
Operator是一个抽象类,实现了IOperationAsync和IContinueWithAsync两个接口。
IOperationAsync实现了异步操作,IContinueWithAsync实现了类似于Task的ContinueWith方法,在当前异步操作完成后继续进行的操作

IOperationAsync接口详解

public interface IOperationAsync{ IAsyncResult Invoke(); void Wait(); void CompletedCallBack(IAsyncResult ar); void CatchException(Exception exception);} Invoke():异步方法的调用 Wait():等待异步操作执行 CompletedCallBack():操作完成回调 CatchException():抓取异常

IContinueWithAsync接口详情

public interface IContinueWithAsync{ Operator PrevIoUs { get; set; } Operator Next { get; set; } Operator ContinueWithAsync(Action action); Operator ContinueWithAsync<TParameter>(Action<TParameter> action,TParameter parameter);}

PrevIoUs:前一个操作
Next:下一个操作
ContinueWithAsync():异步继续操作

public abstract class Operator : IOperationAsync,IContinueWithAsync{ public IAsyncResult Middle; public readonly string Id; public Exception Exception { get; private set; } public Operator PrevIoUs { get; set; } public Operator Next { get; set; } protected Operator() { Id = Guid.NewGuid().ToString(); } public abstract IAsyncResult Invoke(); protected void SetAsyncResult(IAsyncResult result) { this.Middle = result; } public virtual void Wait() { if (!Middle.IsCompleted) Middle.AsyncWaitHandle.WaitOne(); } public virtual void CompletedCallBack(IAsyncResult ar) { } public void CatchException(Exception exception) { this.Exception = exception; } protected Operator ContinueAsync() { if (Next != null) Next.Invoke(); return Next; } public virtual Operator ContinueWithAsync(Action action) { Next = new ActionAsync(action); Next.PrevIoUs = this; return Next; } public virtual Operator ContinueWithAsync<TParameter>(Action<TParameter> action,TParameter parameter) { Next = new ActionAsync<TParameter>(action,parameter); Next.PrevIoUs = this; return Next; } public virtual Operator ContinueWithAsync<TResult>(Func<TResult> func) { Next = new FuncAsync<TResult>(); Next.PrevIoUs = this; return Next; } public virtual Operator ContinueWithAsync<TParameter,TResult>(Func<TParameter,TResult> func,TParameter parameter) { Next = new FuncAsync<TParameter,TResult>(func,parameter); Next.PrevIoUs = this; return Next; }}

无返回异步操作
ActionAsync

public class ActionAsync : Operator{ private readonly Action _action; protected ActionAsync() { } public ActionAsync(Action action) : this() { this._action = action; } public override IAsyncResult Invoke() { var middle = _action.BeginInvoke(CompletedCallBack,null); SetAsyncResult(middle); return middle; } public override void CompletedCallBack(IAsyncResult ar) { try { _action.EndInvoke(ar); } catch (Exception exception) { this.CatchException(exception); } ContinueAsync(); }}public class ActionAsync<T> : ActionAsync{ public T Result; private readonly Action<T> _action1; protected readonly T Parameter1; public ActionAsync() { } public ActionAsync(T parameter) { this.Parameter1 = parameter; } public ActionAsync(Action<T> action,T parameter) { this._action1 = action; this.Parameter1 = parameter; } public override IAsyncResult Invoke() { var result = _action1.BeginInvoke(Parameter1,CompletedCallBack,null); SetAsyncResult(result); return result; } public override void CompletedCallBack(IAsyncResult ar) { try { _action1.EndInvoke(ar); } catch (Exception exception) { this.CatchException(exception); } ContinueAsync(); }}

有返回异步
FuncAsync实现了IFuncOperationAsync接口

IFuncOperationAsync

public interface IFuncOperationAsync<T>{ void SetResult(T result); T GetResult();} SetResult(T result):异步操作完成设置返回值 GetResult():获取返回值

1)、FuncAsync

public class FuncAsync<TResult> : Operator,IFuncOperationAsync<TResult>{private TResult _result;public TResult Result{ get { if (!Middle.IsCompleted || _result == null) { _result = GetResult(); } return _result; }}private readonly Func<TResult> _func1;public FuncAsync(){}public FuncAsync(Func<TResult> func){ this._func1 = func;}public override IAsyncResult Invoke(){ var result = _func1.BeginInvoke(CompletedCallBack,null); SetAsyncResult(result); return result;}public override void CompletedCallBack(IAsyncResult ar){ try { var result = _func1.EndInvoke(ar); SetResult(result); } catch (Exception exception) { this.CatchException(exception); SetResult(default(TResult)); } ContinueAsync();}public virtual TResult GetResult(){ Wait(); return this._result;}public void SetResult(TResult result){ _result = result;}}public class FuncAsync<T1,TResult> : FuncAsync<TResult>{protected readonly T1 Parameter1;private readonly Func<T1,TResult> _func2;public FuncAsync(Func<T1,TResult> action,T1 parameter1) : this(parameter1){ this._func2 = action;}protected FuncAsync(T1 parameter1) : base(){ this.Parameter1 = parameter1;}public override IAsyncResult Invoke(){ var result = _func2.BeginInvoke(Parameter1,null); SetAsyncResult(result); return result;}public override void CompletedCallBack(IAsyncResult ar){ try { var result = _func2.EndInvoke(ar); SetResult(result); } catch (Exception exception) { CatchException(exception); SetResult(default(TResult)); } ContinueAsync();}}

Asynchronous 异步操作封装
ActionAsync和FuncAsync为异步操作打下了基础,接下来最重要的工作就是通过这两个类执行我们的异步操作,为此我封装了一个异步操作类
主要封装了以下几个部分:

WaitAll(IEnumerable<Operator> operations):等待所有操作执行完毕 WaitAny(IEnumerable<Operator> operations):等待任意操作执行完毕 ActionAsync FuncAsync ContinueWithAction ContinueWithFunc

后面四个包含若干个重载,这里只是笼统的代表一个类型的方法
WaitAll

public static void WaitAll(IEnumerable<Operator> operations){foreach (var @operator in operations){ @operator.Wait();}}

WaitAny

public static void WaitAny(IEnumerable<Operator> operations){while (operations.All(o => !o.Middle.IsCompleted)) Thread.Sleep(100);}

等待时间可以自定义
ActionInvoke

public static Operator Invoke(Action action){Operator operation = new ActionAsync(action);operation.Invoke();return operation;}public static Operator Invoke<T>(Action<T> action,T parameter){Operator operation = new ActionAsync<T>(action,parameter);operation.Invoke();return operation;}public static Operator Invoke<T1,T2>(Action<T1,T2> action,T1 parameter1,T2 parameter2){Operator operation = new ActionAsync<T1,T2>(action,parameter1,parameter2);operation.Invoke();return operation;}

FuncInvoke

public static Operator Invoke<TResult>(Func<TResult> func){Operator operation = new FuncAsync<TResult>(func);operation.Invoke();return operation;}public static Operator Invoke<TParameter,TParameter parameter){TParameter param = parameter;Operator operation = new FuncAsync<TParameter,param);operation.Invoke();return operation;}public static Operator Invoke<T1,T2,TResult>(Func<T1,T2 parameter2){Operator operation = new FuncAsync<T1,parameter2);operation.Invoke();return operation;}

ContinueWithAction

public static Operator ContinueWithAsync(IEnumerable<Operator>operators,Action action){return Invoke(WaitAll,operators) .ContinueWithAsync(action);}public static Operator ContinueWithAsync<TParameter>(IEnumerable<Operator> operators,Action<TParameter> action,TParameter parameter){return Invoke(WaitAll,operators) .ContinueWithAsync(action,parameter);}

ContinueWithFunc

public static Operator ContinueWithAsync<TResult>(IEnumerable<Operator> operators,Func<TResult> func){return Invoke(WaitAll,operators) .ContinueWithAsync(func);}public static Operator ContinueWithAsync<TParameter,TResult>(IEnumerable<Operator> operators,Func<TParameter,operators) .ContinueWithAsync(func,parameter);}

这里有个bug当调用ContinueWithAsync后无法调用Wait等待,本来Wait需要从前往后等待每个异步操作,但是测试了下不符合预期结果。不过理论上来说应该无需这样操作,ContinueWithAsync只是为了当上一个异步操作执行完毕时继续执行的异步操作,若要等待,那不如两个操作放到一起,最后再等待依然可以实现。
前面的都是单步异步操作的调用,若需要对某集合进行某个方法的异步操作,可以foreach遍历

public void ForeachAsync(IEnumerbale<string> parameters){ foreach(string p in parameters) { Asynchronous.Invoke(Tast,p); }}public void Test(string parameter){ //TODO:做一些事}

每次都需要去手写foreach,比较麻烦,因此实现类似于PLinq的并行计算方法实在有必要,不过有一点差别,PLinq是采用多核cpu进行并行计算,而我封装的仅仅遍历集合进行异步操作而已
ForeachAction

public static IEnumerable<Operator> Foreach<TParameter>(IEnumerable<TParameter> items,Action<TParameter> action){ return items.Select(t => Invoke(action,t)).ToList();}

ForeachFunc

public static IEnumerable<Operator> Foreach<TParameter,TResult>(IEnumerable<TParameter> items,TResult> func){ return items.Select(parameter => Invoke(func,parameter)).ToList();}

如何使用
无返回值异步方法调用

public void DoSomeThing(){//TODO:}

通过Asynchronous.Invoke(DoSomeThing) 执行

public void DoSomeThing(string parameter){//TODO:}

通过Asynchronous.Invoke(DoSomeThing,parameter) 执行

有返回值异步方法调用

public string DoSomeThing(){//TODO:}

通过Asynchronous.Invoke(()=>DoSomeThing())执行

public string DoSomeThing(string parameter){//TODO:}

通过Asynchronous.Invoke(()=>DoSomeThing(parameter))执行,或者也可以传入参数通过Asynchronous.Invoke(p=>DoSomeThing(p),parameter)

无返回值Foreach

public void Test{int[] parameters = {1,2,3,4,5};Asynchronous.Foreach(parameters,Console.WriteLine);}

有返回值Foreach

public void Test{int[] parameters = {1,5};var operators = Asynchronous.Foreach(parameters,p=> P*2);Asynchrous.WaitAll(operators);Asynchronous.Foreach(operators.Cast<FuncAsync<int,int>>(),p=> Console.WriteLine(p.Result));}

首先将集合每个值扩大2倍,然后输出
异步执行完再执行

public void Test{int[] parameters = {1,p=> P*2);Asynchrous.ContinueWithAsync(operators,Console.WriteLine,”执行完成”);}

每次执行完继续执行
可能有时候我们需要遍历一个集合,每个元素处理完成后我们需要输出XX处理完成

public void Test{int[] parameters = {1,p=> P*2);Asynchronous.Foreach(operators,o=>{ o.ContinueWithAsync(()={ //每个元素执行完时执行 if(o.Exception != null) { //之前执行时产生未处理的异常,这里可以捕获到 } });});}

可以实现链式异步操作

public void Chain(){Asynchronous.Invoke(Console.WriteLine,1).ContinueWithAsync(Console.WriteLine,2).ContinueWithAsync(Console.WriteLine,3)}

这样会按步骤输出1,3
结束语

以上只是列出了部分重载方法,其他重载方法无非就是加参数,本质实际是一样的。

希望对大家的学习有所帮助,在这祝大家新年快乐,新的一年大家一起努力。