C# 从会话存储和检索数据表

如何在会话中存储数据表并在c#net中从会话中检索值？

将数据表添加到会话中：

DataTable Tissues = new DataTable();

Tissues = dal.returnTissues("TestID", "TestValue");// returnTissues("","") sample     function for adding values


Session.Add("Tissues", Tissues);

从会话中检索该数据表：

DataTable Tissues = Session["Tissues"] as DataTable

或

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您可以这样做，但在会话中存储DataSet对象不是很有效。如果你有一个有很多用户的web应用程序，它会很快阻塞你的服务器内存

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如果您真的必须这样做，我建议您在不需要数据集时尽快将其从会话中删除。

这只是一个旁注，但通常您要做的是保持会话和ViewState的大小较小。我通常只在Session和ViewState中存储id和少量数据包

例如，如果要将大块数据从一个页面传递到另一个页面，可以在querystring中存储一个ID，并使用该ID从数据库或文件中获取数据

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PS：但正如我所说，这可能与您的查询完全无关：）

在会话中存储

DataTable

：

DataTable dtTest = new DataTable();
Session["dtTest"] = dtTest; 

要从会话中检索数据表，请执行以下操作：

DataTable dt = (DataTable) Session["dtTest"];

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一个非常常见问题的简单解决方案

                 // DECLARATION
                HttpContext context = HttpContext.Current;
                DataTable dt_ShoppingBasket = context.Session["Shopping_Basket"] as DataTable;

                // TRY TO ADD rows with the info into the DataTable
                try
                {
                    // Add new Serial Code into DataTable dt_ShoppingBasket
                    dt_ShoppingBasket.Rows.Add(new_SerialCode.ToString());

                    // Assigns new DataTable to Session["Shopping_Basket"]
                    context.Session["Shopping_Basket"] = dt_ShoppingBasket;
                }
                catch (Exception)
                {
                    // IF FAIL (EMPTY OR DOESN'T EXIST) - 
                    // Create new Instance, 
                    DataTable dt_ShoppingBasket= new DataTable();

                    // Add column and Row with the info
                    dt_ShoppingBasket.Columns.Add("Serial");
                    dt_ShoppingBasket.Rows.Add(new_SerialCode.ToString());

                    // Assigns new DataTable to Session["Shopping_Basket"]
                    context.Session["Shopping_Basket"] = dt_PanierCommande;
                }



                // PRINT TESTS
                DataTable dt_To_Print = context.Session["Shopping_Basket"] as DataTable;

                foreach (DataRow row in dt_To_Print.Rows)
                {
                    foreach (var item in row.ItemArray)
                    {
                        Debug.WriteLine("DATATABLE IN SESSION: " + item);
                    }
                }

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会话[“BufferDatatable”]=dt；（（DataTable）会话[“BufferDatatable”]）.Rows.Add（titlelbl.Text，txtEnable.Text，txtValue.Text，txtValue.Text）；解决了问题。在这种情况下，您可以提供指南吗？我认为这会影响应用程序/页面的性能，例如，如果datatable包含10000条记录。@Musikero31根据您使用它的方式，它可以提高网页的性能。

                 // DECLARATION
                HttpContext context = HttpContext.Current;
                DataTable dt_ShoppingBasket = context.Session["Shopping_Basket"] as DataTable;

                // TRY TO ADD rows with the info into the DataTable
                try
                {
                    // Add new Serial Code into DataTable dt_ShoppingBasket
                    dt_ShoppingBasket.Rows.Add(new_SerialCode.ToString());

                    // Assigns new DataTable to Session["Shopping_Basket"]
                    context.Session["Shopping_Basket"] = dt_ShoppingBasket;
                }
                catch (Exception)
                {
                    // IF FAIL (EMPTY OR DOESN'T EXIST) - 
                    // Create new Instance, 
                    DataTable dt_ShoppingBasket= new DataTable();

                    // Add column and Row with the info
                    dt_ShoppingBasket.Columns.Add("Serial");
                    dt_ShoppingBasket.Rows.Add(new_SerialCode.ToString());

                    // Assigns new DataTable to Session["Shopping_Basket"]
                    context.Session["Shopping_Basket"] = dt_PanierCommande;
                }



                // PRINT TESTS
                DataTable dt_To_Print = context.Session["Shopping_Basket"] as DataTable;

                foreach (DataRow row in dt_To_Print.Rows)
                {
                    foreach (var item in row.ItemArray)
                    {
                        Debug.WriteLine("DATATABLE IN SESSION: " + item);
                    }
                }