在Azure函数中捕获异步方法异常

Question

我已经使用C#（库项目）和Aspect（AOP）编写了Azure函数v1用于日志记录。我在catch块中没有得到异常。

捕获异步方法引发的异常

我有上面讨论的相同问题，但Azure函数运行方法是异步任务，其异常处理和异步void相同。不确定哪里有问题？假设这是函数SDK问题。

Azure函数

public static class PingFunction
{
    [LoggerAspect]
    [FunctionName("PingFunction")]
    public static async Task<HttpResponseMessage> Run([HttpTrigger(AuthorizationLevel.Anonymous, "get", "post", Route = null)]HttpRequestMessage req, TraceWriter log)
    {
        string name = string.Empty;
        log.Info("C# HTTP trigger function processed a request.");

            SomeService someService = new SomeService();
            await someService.DoSomething();

        return req.CreateResponse(HttpStatusCode.OK, "Hello " + name);
    }
}

public class SomeService
{
    public async Task DoSomething()
    {
        await Task.Delay(1000);
        throw new Exception("Exception from Service");
    }
}

记录器方面

public class LoggerAspectAttribute : Attribute, IMethodAdvice
{
    public void Advise(MethodAdviceContext context)
    {
        //Logger initilizer here
        Console.WriteLine($"{context.TargetType.Name} started...");
        try
        {
            context.Proceed(); // this calls the original method
        }
        catch (Exception ex)
        {
            Console.WriteLine(ex.Message);
        }
        finally
        {
            Console.WriteLine($"{context.TargetType.Name} completed...");
        }
    }
}

解决方法：当我从Azure函数中删除异步等待并通过“getWaiter（）.GetResult（）”调用异步方法时，它就可以工作了。

public static HttpResponseMessage Run([HttpTrigger(AuthorizationLevel.Anonymous, "get", "post", Route = null)]HttpRequestMessage req, TraceWriter log)
    {
        string name = string.Empty;
        log.Info("C# HTTP trigger function processed a request.");

        SomeService someService = new SomeService();
        someService.DoSomething().GetAwaiter().GetResult();

        return req.CreateResponse(HttpStatusCode.OK, "Hello " + name);
    }

Task.GetAwaiter（）。GetResult（）方法可能导致死锁问题，应避免使用异步/等待。

我的函数每天处理数百万个事件。如果这是FunctionSDK问题或其他问题，这是正确的解决方案吗？

Answer 1

您需要编写异步建议，例如：

public class LoggerAspectAttribute : Attribute, IMethodAsyncAdvice
{
    public async Task Advise(MethodAsyncAdviceContext context)
    {
        //Logger initilizer here
        Console.WriteLine($"{context.TargetType.Name} started...");
        try
        {
            await context.ProceedAsync(); // this calls the original method
        }
        catch (Exception ex)
        {
            Console.WriteLine(ex.Message);
        }
        finally
        {
            Console.WriteLine($"{context.TargetType.Name} completed...");
        }
    }
}

编辑:是的，它适用于Mr建议:)