问用web方式调用营业执照识别API，经常是第一次可以识别，后面再次调用，就需要回收IIS应用程序池？

我是参照这篇文章 https://cloud.tencent.com/developer/article/1395819

来解决WEB异步调用返回数据的问题，但问题是经常第一次可以识别，后面再次调用，就需要回收IIS应用程序池。否则就卡在 BizLicenseOCRResponse resp = await client.BizLicenseOCR(req);这一行代码，没有异常也没有返回。这是为什么呢？

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代码如下：

using System;

using System.Collections.Generic;

using System.Configuration;

using System.Linq;

using System.Text;

using System.Threading.Tasks;

using System.Collections;

using TencentCloud.Common;

using TencentCloud.Common.Profile;

using TencentCloud.Ocr.V20181119;

using TencentCloud.Ocr.V20181119.Models;

using MZSP.API.BLL;

using MZSP.DAL;

using MZSP.Entity;

namespace MZSP.View.BLL.Controls

{

class OCRLicenseControl

{

private async Task<BizLicenseOCRResponse> GetAddress(string pLicenseImgUrl)

{

Credential cred = new Credential

{

SecretId = ConfigurationManager.AppSettings["spSecId"].ToString(),

SecretKey = ConfigurationManager.AppSettings["spSecKey"].ToString()

};

ClientProfile clientProfile = new ClientProfile();

HttpProfile httpProfile = new HttpProfile();

httpProfile.Endpoint = ("ocr.tencentcloudapi.com");

clientProfile.HttpProfile = httpProfile;

OcrClient client = new OcrClient(cred, "ap-guangzhou", clientProfile);

BizLicenseOCRRequest req = new BizLicenseOCRRequest();

string strParams = "{\"ImageUrl\":\"" + pLicenseImgUrl + "\"}";

req = BizLicenseOCRRequest.FromJsonString<BizLicenseOCRRequest>(strParams);

BizLicenseOCRResponse resp = await client.BizLicenseOCR(req);

return resp;

}

public object GetShoolInfoFromLicense(string pLicenseImgUrl)

{

Hashtable hs = new Hashtable();

BizLicenseOCRResponse result = null;

try

{

var t = Task.Run(() =>

{

// 同步方式调用，会卡住直到请求返回

result = GetAddress(pLicenseImgUrl).ConfigureAwait(false).GetAwaiter().GetResult();

});

// 同步等待，会卡住直到线程返回

t.Wait();

Tschools school = new Tschools();

GetPrivonceCity(result.RegNum, ref school);

school.FSchoolName = result.Name;

school.FOwner = result.Person;

school.FAddress = result.Address;

hs["SchoolInfoFromLicense"] = school;

hs["msg"] = "营业执照识别成功";

hs["flag"] = true;

}

catch (Exception e)

{

FuncUtility.Utils.WriteErrLogToTxt("营业执照识别失败", e);

hs["msg"] = "营业执照识别失败";

hs["flag"] = false;

}

return hs;

}

private void GetPrivonceCity(string RegNum, ref Tschools school)

{

school.FProvince = TareaBLL.GetInstance().GetOneByID(RegNum.Substring(2, 2)).FAreaName;

school.FCity = TareaBLL.GetInstance().GetOneByID(RegNum.Substring(2, 4)).FAreaName;

school.FCounty = TareaBLL.GetInstance().GetOneByID(RegNum.Substring(2, 6)).FAreaName;

}

}

}