GridView实战二：使用ObjectDataSource数据源控件(自定义缓存机制实现Sort)

  参考资料：http://www.cnblogs.com/fsjohnhuang/archive/2011/12/17/2291200.html

　因为使用ObjectDataSource自带的缓存机制无法实现排序功能，苦苦寻觅终于找到了解决方案。参考后觉得还是自己实操一下比较安心，下面是对《GridView实战二：使用ObjectDataSource数据源控件》的改进！！

  CL代码：

public class CL
{
    private OdsDataManager om = new OdsDataManager();
    private static string[] mainKey = {"ods"};

    public CL()
    {
    }

    public DataTable GetRecord(int maximumRows, int startRowIndex, string sortExpression)
    {
        DataTable dt = HttpRuntime.Cache[GetCacheKey(Convert.ToString(maximumRows) + startRowIndex)] as DataTable;
        if (dt == null)
        {
            dt = om.GetRecord(maximumRows, startRowIndex, sortExpression);
            AddCache(Convert.ToString(maximumRows) + startRowIndex, dt);
        }
        if (!string.IsNullOrEmpty(sortExpression))
        {
            DataTable tempDt = dt.Clone();
            DataRow[] drs = dt.Select("",sortExpression);
            foreach (DataRow dr in drs)
            {
                tempDt.Rows.Add(dr.ItemArray);
            }
            dt = tempDt;
        }

        return dt;
    }

    public int GetRecordCount()
    {
        return om.GetRecordCount();
    }

    public bool UpdateRecord(int ID, string Name, string Sex, string Country, string Hobby)
    {
        RemoveCache();
        return om.UpdateRecord(ID,Name,Sex,Country,Hobby);
    }

    public bool DelRecord(int ID)
    {
        RemoveCache();
        return om.DelRecord(ID);
    }

    public DataTable GetCountry()
    {
        DataTable countryDt = HttpRuntime.Cache["countryDt"] as DataTable;
        return countryDt;
    }

    public DataTable GetHobby()
    {
        DataTable hobbyDt = HttpRuntime.Cache["hobbyDt"] as DataTable;
        return hobbyDt;
    }

    private void AddCache(string key, object data)
    {
        System.Web.Caching.Cache dc = HttpRuntime.Cache;
        if (dc[mainKey[0]] == null)
            dc.Insert(mainKey[0], DateTime.Now);

        System.Web.Caching.CacheDependency cd = new System.Web.Caching.CacheDependency(null, mainKey);
        dc.Insert(GetCacheKey(key), data, cd, System.Web.Caching.Cache.NoAbsoluteExpiration, System.Web.Caching.Cache.NoSlidingExpiration);
    }

    private void RemoveCache()
    {
        System.Web.Caching.Cache dc = HttpRuntime.Cache;
        if (dc[mainKey[0]] != null)
            dc[mainKey[0]] = DateTime.Now;
    }

    private string GetCacheKey(string key)
    {
        return mainKey[0] + "-" + key;
    }
}

实现预加载(proactive loading)
Global.asax

void Application_Start(object sender, EventArgs e)
    {
        // 在应用程序启动时运行的代码
        OdsDataManager om = new OdsDataManager();
        HttpRuntime.Cache.Insert("countryDt", om.GetCountry(), null,
            System.Web.Caching.Cache.NoAbsoluteExpiration,
            System.Web.Caching.Cache.NoSlidingExpiration, CacheItemPriority.NotRemovable, null);
        HttpRuntime.Cache.Insert("hobbyDt", om.GetHobby(), null,
            System.Web.Caching.Cache.NoAbsoluteExpiration,
            System.Web.Caching.Cache.NoSlidingExpiration, CacheItemPriority.NotRemovable, null);
        om = null;
    }