Azure连接字符串 - 未将对象引用设置为对象的实例

我正在尝试在Windows控制台应用程序中下载azure blob . 当我构建和调试应用程序时，我的azure连接字符串抛出异常 . 这个字符串在我的其他asp.net应用程序中工作正常 .

违规行是：

CloudStorageAccount storageAccount = CloudStorageAccount.Parse(ConfigurationManager.ConnectionStrings["DefaultEndpointsProtocol=https;AccountName=xxxxx;AccountKey=xxxxx==;BlobEndpoint=https://xxxxx.blob.core.windows.net/;TableEndpoint=https://xxxxx.table.core.windows.net/;QueueEndpoint=https://xxxxx.queue.core.windows.net/;FileEndpoint=https://xxxxx.file.core.windows.net/"].ConnectionString);

我的代码是：

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading.Tasks;
using System.Collections;
using Microsoft.WindowsAzure;
using Microsoft.WindowsAzure.Storage;
using Microsoft.WindowsAzure.Storage.Auth;
using Microsoft.WindowsAzure.Storage.Blob;
using System.Configuration;
using System.IO;
using System.Data;
using System.Data.SqlClient;
using System.Threading;

namespace CPGetAdverts
{
    class Program
    {
        static void Main(string[] args)
        {
            // Retrieve storage account from connection string.
            CloudStorageAccount storageAccount = CloudStorageAccount.Parse(ConfigurationManager.ConnectionStrings["DefaultEndpointsProtocol=https;AccountName=xxxxx;AccountKey=xxxxx==;BlobEndpoint=https://xxxxx.blob.core.windows.net/;TableEndpoint=https://xxxxx.table.core.windows.net/;QueueEndpoint=https://xxxxx.queue.core.windows.net/;FileEndpoint=https://xxxxx.file.core.windows.net/"].ConnectionString);
            // Create the blob client.
            CloudBlobClient blobClient = storageAccount.CreateCloudBlobClient();
            // Retrieve a reference to a container.
            var container = blobClient.GetContainerReference("newadverts").ListBlobs();
            // Retrieve filenames from container List
            var urls = new List<string>();
            int fileName = 1;

            foreach (var blob in container)
            {
                using (var fileStream = System.IO.File.OpenWrite(@"\home\pi\Pictures\" + fileName + ".jpg"))
                {
                    var blobReference = blobClient.GetBlobReferenceFromServer(blob.Uri);
                    blobReference.DownloadToStream(fileStream);
                    fileName++;
                }
            }

        }
    }
}

例外是：

System.NullReferenceException未处理HResult = -2147467261 Message =对象引用未设置为对象的实例 . 源= CPGetAdverts堆栈跟踪：在CPGetAdverts.Program.Main（字串[] args）在C：\用户\ Diarmaid \文件\的Visual Studio 2015 \项目\ CPGetAdverts \ CPGetAdverts \ Program.cs的：线24在System.AppDomain._nExecuteAssembly（ RuntimeAssembly组件，字串[] args）在System.AppDomain.ExecuteAssembly（字符串assemblyFile，证据assemblySecurity，字串[] args）在Microsoft.VisualStudio.HostingProcess.HostProc.RunUsersAssembly（）在System.Threading.ThreadHelper.ThreadStart_Context（对象状态）在System.Threading.ExecutionContext.RunInternal（的ExecutionContext的ExecutionContext，ContextCallback回调，对象的状态，布尔preserveSyncCtx）在System.Threading.ExecutionContext.Run（的ExecutionContext的ExecutionContext，ContextCallback回调，对象的状态，布尔preserveSyncCtx）在System.Threading.ExecutionContext.Run （ExecutionContext executionContext，ContextCallback回调，对象状态）在System.Threading.ThreadHelper.ThreadStart（）InnerException：

有没有人有任何想法吗？