how to Store Datagridview in cache and retrieve?

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C#

C#4.0

Hi,
How to store a datagridview in cache and how to retrieve that datagridview and asign?

public void StoreGridInCache(String CacheKey, DataGridView _dataGrid)
        {
            //DataTable dtInCache = new DataTable();

            HttpRuntime.Cache.Add(CacheKey, _dataGrid, null, DateTime.Now.AddHours(1), TimeSpan.Zero, CacheItemPriority.High, null);

            return;
        }

this.dataGridViewPopupDetails.DataSource = (DataGridView)HttpRuntime.Cache.Get(CacheKey);

In this code the datagridview not displaying...how to rectify this?