运行func host start时ConnectionStringSetting未找到错误求助

错误原因 #

编译错误CS0246的核心原因是CosmosDB绑定属性的参数名称错误：在新版Microsoft.Azure.WebJobs.Extensions.CosmosDB包中，指定连接字符串的参数名是ConnectionString，而非你代码中使用的ConnectionStringSetting。

修复步骤 #

1. 修正绑定参数名称 #

将两个CosmosDB属性中的ConnectionStringSetting替换为ConnectionString。

2. 修正代码拼写错误 #

代码中jsonToRetun是拼写错误，改为jsonToReturn；同时建议返回更新后的计数器对象（updatedCounter），确保前端能拿到最新的访问次数。

3. 验证NuGet包版本 #

确保项目已安装最新稳定版的Microsoft.Azure.WebJobs.Extensions.CosmosDB，可通过以下命令更新：

dotnet add package Microsoft.Azure.WebJobs.Extensions.CosmosDB

修正后的完整代码 #

using Microsoft.Azure.WebJobs;
using Microsoft.Azure.WebJobs.Extensions.Http;
using Microsoft.AspNetCore.Http;
using Microsoft.Extensions.Logging;
using Newtonsoft.Json;
using System.Net.Http;
using System.Text;
using Microsoft.Azure.WebJobs.Extensions.CosmosDB;

namespace Company.Function
{
    public static class GetResumeCounter
    {
        [FunctionName("GetResumeCounter")]
        public static HttpResponseMessage Run(
            [HttpTrigger(AuthorizationLevel.Function, "get", "post", Route = null)] HttpRequest req,
            [CosmosDB(databaseName: "AzureResume", containerName:"Counter", ConnectionString = "AzureResumeConnectionString", Id="1", PartitionKey="1")] Counter counter,
            [CosmosDB(databaseName: "AzureResume", containerName:"Counter", ConnectionString = "AzureResumeConnectionString", Id="1", PartitionKey="1")] out Counter updatedCounter,             
            ILogger log)
        {
            log.LogInformation("C# HTTP trigger function processed a request.");

            updatedCounter = counter;
            updatedCounter.Count += 1;
            
            var jsonToReturn = JsonConvert.SerializeObject(updatedCounter);

            return new HttpResponseMessage(System.Net.HttpStatusCode.OK)
            {
                Content = new StringContent(jsonToReturn, Encoding.UTF8, "application/json")
            };
        }
    }

    // 确保你已定义Counter类（可放在本文件或单独文件中）
    public class Counter
    {
        public string Id { get; set; }
        public string PartitionKey { get; set; }
        public int Count { get; set; }
    }
}

额外注意事项 #

• 确认local.settings.json中已正确配置连接字符串：

  {
    "IsEncrypted": false,
    "Values": {
      "AzureWebJobsStorage": "UseDevelopmentStorage=true",
      "FUNCTIONS_WORKER_RUNTIME": "dotnet",
      "AzureResumeConnectionString": "你的CosmosDB连接字符串"
    }
  }
  

• 若问题仍存在，尝试清理并重新构建项目：

  dotnet clean
  dotnet build
  func host start
  

内容的提问来源于stack exchange，提问作者kamlesh