Windows Azure实战:如何创建云数据存储-云计算专区

Windows Azure实战:如何创建云数据存储

作者：小罗编辑：洪钊峰 2010-05-21 09:22 IT168网站原创

　　第4步：创建CloudDataService文件夹

　　在同一个项目中，创建一个CloudDataService文件夹，在它上面增加三个接口定义 – IdataTableService，IHasDependencyTableService和INoDependencyTableService。IDataTableService接口暴露三个基本的数据表访问功能 – Insert，Update和Delete，所有这些功能都接受Microsoft.Samples.ServiceHosting.StorageClient命名空间中定义的TableStorageEntity类参数;其它两个接口都衍生自IDataTableService接口，IHasDependencyTableService接口暴露UpdateDependencyTable()方法，它也接受TableStorageEntity类参数;INoDependencyTableService接口不暴露任何方法，但它提供了一个类型定义，用于标记一个类为无逻辑依赖数据对象。

　　第5步：在CloudDataService文件夹下添加两个类

　　接下来在CloudDataServices文件夹中增加两个类 – DataTableService和AddressTableService，将第一个类标记为抽象类，AddressTableService类是DataTableService类的衍生类。

　　所有类和接口的代码如下：

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;

namespace CreateDataStorage.Models.CloudDataServices
{
    using Microsoft.Samples.ServiceHosting.StorageClient;

    public interface IDataTableService
    {
        bool Insert(TableStorageEntity entity);
        bool Update(TableStorageEntity entity);
        bool Delete(TableStorageEntity entity);
    }

    public interface IHasDependencyTableService : IDataTableService
    {
        bool UpdateDependencyTable(TableStorageEntity entity);
    }
public interface INoDependencyTableService : IDataTableService
    {
    }
}

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;

namespace CreateDataStorage.Models.CloudDataServices
{
    using Microsoft.Samples.ServiceHosting.StorageClient;
    using CreateDataStorage.Models.CloudDataContext;

    abstract public class DataTableService
    {
        protected UserDataContext _userDataContext = null;
        protected string _Table { get; set; }

        public DataTableService()
        {
            _userDataContext = new UserDataContext();
        }

        public UserDataContext DataContext() { return _userDataContext; }

        virtual public bool Insert(TableStorageEntity entity)
        {
            bool success = false;

            try
            {
                if (this is IHasDependencyTableService)
                {
                    (this as IHasDependencyTableService).UpdateDependencyTable(entity);
                }
                _userDataContext.AddObject(_Table, entity);
                _userDataContext.SaveChanges();
                success = true;
            }
            catch { }

            return success;
        }

        public bool Update(TableStorageEntity entity)
        {
            bool success = false;

            try
   {
                if (Delete(entity))
                {
                    success = Insert(entity);
                }
            }
            catch { }

            return success;
        }

        virtual public bool Delete(TableStorageEntity entity)
        {
            bool success = false;

            try
            {
                if (this is IHasDependencyTableService)
                {
                    (this as IHasDependencyTableService).UpdateDependencyTable(entity);
                }
                _userDataContext.DeleteObject(entity);
                _userDataContext.SaveChanges();
                success = true;
            }
            catch { }

            return success;
        }
    }
}

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Configuration;

namespace CreateDataStorage.Models.CloudDataServices
{
    using Microsoft.Samples.ServiceHosting.StorageClient;
    using CreateDataStorage.Models.CloudData;

    public class AddressTableService : DataTableService, INoDependencyTableService
    {
        public AddressTableService()
        {
            _Table = ConfigurationManager.AppSettings["AddressTable"];
        }
    }
}

第1页：创建新的Worker Cloud Service项目第2页：创建CloudDataService文件夹第3页：添加UserDataContext类第4页：创建测试存储表第5页：可遵循的一些规则和最佳实践

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