Question

我正在尝试从Azure函数调用face api异步方法。我正在等待异步方法，但是Azure函数关闭并完成它。如何等待Azure功能完成异步操作？

这是我的代码（我正在使用VS 2017，.Net标准2.0）：

public static class IdentifyHttp
{
    [FunctionName("IdentifyHttp")]
    public static IActionResult Run([HttpTrigger(AuthorizationLevel.Function, "get", "post", Route = null)]HttpRequest req, TraceWriter log)
    {
        log.Info("C# HTTP trigger function processed a request.");


        string url = new StreamReader(req.Body).ReadToEnd();            

        //string url = req.Query["url"];

        Stream rtn = null;
        HttpWebRequest aRequest = (HttpWebRequest)WebRequest.Create(url);
        HttpWebResponse aResponse = (HttpWebResponse)aRequest.GetResponse();

        StreamReader sReader = new StreamReader(aResponse.GetResponseStream(), System.Text.Encoding.Default);

            rtn = sReader.BaseStream;           

        AnalyzeImageFaceAPIAsync(rtn);

        return url != null
            ? (ActionResult)new OkObjectResult($"Hello, {url}")
            : new BadRequestObjectResult("Please pass a name on the query string or in the request body");
    }

    private static async void AnalyzeImageFaceAPIAsync(Stream s)
    {

        string PersonGroupId = "employees";
        FaceServiceClient FaceServiceAPIClient = new FaceServiceClient("xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx", "https://eastus.api.cognitive.microsoft.com/face/v1.0");
        string name = "No one identified";

        //s.Seek(0, SeekOrigin.Begin);
        var faces = await FaceServiceAPIClient.DetectAsync(s);
        var faceIds = faces.Select(face => face.FaceId).ToArray();

        var results = await FaceServiceAPIClient.IdentifyAsync(PersonGroupId, faceIds);
        foreach (var identifyResult in results)
        {
            if (identifyResult.Candidates.Length > 0)
            {
                var candidateId = identifyResult.Candidates[0].PersonId;
                var person = await FaceServiceAPIClient.GetPersonAsync(PersonGroupId, candidateId);
                name = person.Name;


            }
        }
    }
}

Answer 1

您应该使用async Task AnalyzeImageFaceAPIAsync而不是async void AnalyzeImageFaceAPIAsync声明函数。如果AnalyzeImageFaceAPIAsync中有任何错误，它们不会填充到您的主要功能中，而您必须等待自己的功能，并带有以下内容：await AnalyzeImageFaceAPIAsync(rtn);

如何在azure函数中等待异步调用

1 个答案: