Azureのストレージのブロブにデータがあるかを調べる方法

using System;

using System.Collections.Generic;

using System.Linq;

using System.Net;

using System.Web;

using System.Web.UI;

using System.Web.UI.WebControls;

using Microsoft.WindowsAzure;

using Microsoft.WindowsAzure.ServiceRuntime;

using Microsoft.WindowsAzure.StorageClient;

namespace WebRole1

{

    public partial class _Default : System.Web.UI.Page

    {

        public static CloudStorageAccount CSA   // get CloudStorageAccount

        {

            get;

            set;

        }

        private static CloudBlobClient cloudBlobClient = null;

        public static CloudBlobClient CBC  // get CloudBlobClient

        {

            get

            {

                if (cloudBlobClient != null) return cloudBlobClient;

                cloudBlobClient = CSA.CreateCloudBlobClient();

                return cloudBlobClient;

            }

        }

        protected void Page_Load(object sender, EventArgs e)

        {

            CloudStorageAccount.SetConfigurationSettingPublisher((configName, configSetter) =>

            {

                configSetter(RoleEnvironment.GetConfigurationSettingValue(configName));

                RoleEnvironment.Changed += (mysender, arg) =>

                {

                    if (arg.Changes.OfType<RoleEnvironmentConfigurationSettingChange>()

                        .Any((change) => (change.ConfigurationSettingName == configName)))

                    {

                        if (!configSetter(RoleEnvironment.GetConfigurationSettingValue(configName)))

                        {

                            RoleEnvironment.RequestRecycle();

                        }

                    }

                };

            });

            CSA = CloudStorageAccount.FromConfigurationSetting("DataConnectionString");

            CloudBlobContainer cont = CBC.GetContainerReference("testcontainer001");

            cont.CreateIfNotExist();

            // 正常ケースのテスト。アップロードしたアイテムはあるはず

            CloudBlob blob1 = cont.GetBlobReference("test001");

            blob1.UploadText("Hello!\r\n");

            string result1 = blob1.DownloadText();

            // 見つからないケース

            string result2;

            try

            {

                CloudBlob blob2 = cont.GetBlobReference("test002");

                blob2.FetchAttributes();

                result2 = "Succeded!\r\n";

            }

            catch (StorageClientException ex)

            {

                //if( ex.ErrorCode == StorageErrorCode.BlobNotFound ) //←これではダメ

                if (ex.ErrorCode == StorageErrorCode.ResourceNotFound) //←これなら動いた

                {

                    result2 = "not found\r\n";  // 見つからないケース

                }

                else

                {

                    result2 = ex.ToString() + "\r\n";   // その他のエラーになったケース

                }

            }

            Label1.Text = string.Format("{0} {1}", result1, result2);

        }

    }

}