无法获取 wcf 数据成员值

我正在尝试将数据成员添加到 wcf 应用程序，但未能获取其值。我在服务中创建了一个 DataContract 类，并在控制台应用程序中将该值设置为此 DataContract 类的对象。但是，我未能获得我分配的值。以下是服务代码。

namespace WcfServices
{   
    [ServiceContract]
    public interface ICDNManagementService
    {
        [OperationContract]
        [WebInvoke(Method = "POST", UriTemplate = "SetBlobInformation")]
        void SetBlobInformation(BlobInformation blobInformation);
        [OperationContract]
        [WebInvoke(Method = "GET", UriTemplate = "GetBlobInformation")]
        BlobInformation GetBlobInformation();
    }
    [DataContract]
    public class BlobInformation
    {
        string _azureBlobUrl;
        [DataMember]
        public string azureBlobUrl
        {
            get
            {
                return _azureBlobUrl;
            }
            set
            {
                _azureBlobUrl = value;
            }
        }
    }
}

和

namespace WcfServices
{
    public class CDNManagementService : ICDNManagementService
    {
        BlobInformation blobInformation = new BlobInformation();
        public void SetBlobInformation(BlobInformation blobinformation)
        {
            Logger.Log("azureBlobUrl= " + blobinformation.azureBlobUrl);
            Logger.Log("Before SetBlobInformation: " + blobInformation.azureBlobUrl);
            blobInformation = blobinformation;
            Logger.Log("After SetBlobInformation: " + blobInformation.azureBlobUrl);
        }
        public BlobInformation GetBlobInformation()
        {
            Logger.Log("In GetBlobInformation: " + blobInformation.azureBlobUrl);
            return blobInformation;            
        }
    }
}

我的客户端代码如下。

namespace StringParser
{
    class Program
    {
        static void Main(string[] args)
        {
            string blobUrl = "MyBlobUrl";
            CDNManagementService objCDNManagementService = new CDNManagementService();
            BlobInformation objBlobInformation = new BlobInformation();
            objBlobInformation.azureBlobUrl = blobUrl;
            objCDNManagementService.SetBlobInformation(objBlobInformation);
            BlobInformation tmpBlobInformation = new BlobInformation();
            tmpBlobInformation = objCDNManagementService.GetBlobInformation();
            Console.WriteLine(tmpBlobInformation.azureBlobUrl);
            Console.WriteLine("Hello World");
        }
     }
}

控制台输出：

Hello World

我记录的消息是：

azureBlobUrl= MyBlobUrl
Before SetBlobInformation:
After SetBlobInformation: MyBlobUrl
In GetBlobInformation:

为什么我在控制台输出中没有获得"MyBlobUrl"，在日志中没有收到"In GetBlobInformation： MyBlobUrl"？我在这里做错了什么或错过了什么吗？任何帮助，不胜感激。

更新：

我在服务中添加了一个构造函数：

public class CDNManagementService : ICDNManagementService
{
    BlobInformation _blobInformation = new BlobInformation();
    public CDNManagementService()
    {
        _blobInformation.azureBlobUrl = "DefaultUrl";
    }
    ......
}

客户端代码：

    string blobUrl = "MyBlobUrl";
    CDNManagementService objCDNManagementService = new CDNManagementService();
    BlobInformation objBlobInformation = new BlobInformation();
    objBlobInformation = objCDNManagementService.GetBlobInformation();
    Console.WriteLine(objBlobInformation.azureBlobUrl);
    objBlobInformation.azureBlobUrl = blobUrl;
    objCDNManagementService.SetBlobInformation(objBlobInformation);
    BlobInformation tmpBlobInformation = new BlobInformation();
    tmpBlobInformation = objCDNManagementService.GetBlobInformation();
    Console.WriteLine(tmpBlobInformation.azureBlobUrl);

控制台输出：

DefaultUrl
DefaultUrl
Hello World

记录的消息：

In GetBlobInformation: DefaultUrl
azureBlobUrl= MyBlobUrl
Before SetBlobInformation: DefaultUrl
After SetBlobInformation: MyBlobUrl
In GetBlobInformation: DefaultUrl

似乎在每次调用操作合同之前都调用了构造函数。有人知道这里发生了什么吗？谢谢。

namespace WcfServices
{
    public class CDNManagementService : ICDNManagementService
    {
        BlobInformation _blobInformation = new BlobInformation();
        public void SetBlobInformation(BlobInformation blobinformation)
        {
            Logger.Log("azureBlobUrl= " + blobinformation.azureBlobUrl);
            Logger.Log("Before SetBlobInformation: " + _blobInformation.azureBlobUrl);
            _blobInformation = blobinformation;
            Logger.Log("After SetBlobInformation: " + _blobInformation.azureBlobUrl);
        }
        public BlobInformation GetBlobInformation()
        {
            Logger.Log("In GetBlobInformation: " + _blobInformation.azureBlobUrl);
            return _blobInformation;            
        }
    }
}