c# – 使用async / await的最佳实践

public class Calculator
{
    public CalculatorResult Calculate()
    {
        return LongRunningCalculation();
    }

    private CalculatorResult LongRunningCalculation()
    {
        return new CalculatorResult(0.00);
    }
}

public class ClassThatUsesACalculator
{
    private readonly Calculator calculator;

    public ClassThatUsesACalculator()
    {
        this.calculator = new Calculator();
    }

    public void DoWork()
    {
        for (int i = 0; i < 10; i++)
        {
            var result = calculator.Calculate();

            DoSomethingWithCalculationResult(result);

            DoLightWork();

            OnProgressChanged();
        }
    }
}

public partial class Form : Form
{
    public Form()
    {
        InitializeComponent();
    }

    private void Method(object sender,EventArgs e)
    {
        DoWork();
    }

    private void DoWork()
    {
        var calculator = new ClassThatUsesACalculator();
        calculator.ProgressChanged += (s,e) =>
        {
            // Update progressbar
        };

        calculator.DoWork();
    }
}

如果我想在DoWork()中完成工作,在表单上,??异步地我可以添加一个方法(GetCalculationTask),它使用Task.Run()返回一个任务,并添加一个异步事件处理程序,即一个按钮(MethodOne).

如果我错了,请纠正我,但在我看来,当ClassThatUsesACalculator和Calculator类驻留在我不拥有的库中时,这将是唯一的选择.

private Task GetCalculationTask(IProgress<CalculatorProgress> progress)
{
    var calculator = new ClassThatUsesACalculator();
    calculator.ProgressChanged += (s,e) =>
    {
        progress.Report(new CalculatorProgress(0));
    };

    return Task.Run(() =>
    {
        calculator.DoWork();
    });
}

private async void MethodOne(object sender,EventArgs e)
{
    IProgress<CalculatorProgress> progress = new Progress<CalculatorProgress>   (UpdateProgressBar);

    await GetCalculationTask(progress);
}

在我拥有库的情况下,我认为还有两个选项,其中一个与第一个非常相似.可能是由于缺乏我自己的理解.

在ClassThatUsesACalculator上创建一个封装DoWork()方法的方法,然后从表单上的异步方法调用该方法.

要么,

>使用Task.Run()封装Calculator类上的LongRunningCalculation().

public Task<CalculatorResult> CalculateAsync()
{
    return Task.Run(() =>
    {
        return LongRunningCalculation();
    });
}

>在ClassThatUsesACalculator上创建等待新创建方法的调用的异步方法.

public async Task DoWorkAsync()
{
    for (int i = 0; i < 10; i++)
    {
        var result = await calculator.CalculateAsync();

        DoSomethingWithCalculationResult(result);

        DoLightWork();

        OnProgressChanged(); 
    }
}

>在表单上创建一个异步方法(MethodThree)

private async void MethodThree(object sender,EventArgs e)
{
    IProgress<CalculatorProgress> progress = new Progress<CalculatorProgress>(UpdateProgressBar);

    var calculator = new ClassThatUsesACalculator();
    calculator.ProgressChanged += (s,args) =>
    {
        progress.Report(new CalculatorProgress(0));
    };

    await calculator.DoWorkAsync();
}

现在,在我看来,最后一个选项将是最好的,因为我会保持更多的控制权.但也许我已经离开了,希望得到某人的意见或指示,因为我只能找到关于如何消耗异步的解释,但从来没有真正如何构建其他人消费的方法.