does gridview save data in viewstate?

问题

hi i bind a DataTable to a gridview. i want to use the DataTable in some postback event, and ii want to use viewstate. does gridview save data in viewstate? if no what is the best way to do this.

(full story : i have a custom gridview derived from standard asp.net gridview, and i put a button in header to export data to excel, i want to use data saved in viewstate to export to excel)

thanks

回答1:

The short answer is yes, information shown in the GridView, much like the current state of any control, is stored in ViewState. However, I do not think it is easy, if even possible, to get to this data yourself out of the ViewState collection that is available to WebControls. Instead, ASP.NET populates values from ViewState before running event handlers in the lifecycle, so if you interrogate your GridView object server-side in a handler, you should see the current values of the cells.

回答2:

There are other ways like:

1: Storing your DataTable in Session

2: Depending on how often that export button is going to be used and the amount of data fetched, you can make a DB call.

回答3:

Below Statement would make the idea clear:

It Clearly shows that gridview data is stored in viewstate:

//Binding GridView
gv_Settlements.DataSource = dt_settlements;
gv_Settlements.DataBind();

//Retrieving Data
DataTable dt = (DataTable)gv_Settlements.DataSource;

来源：https://stackoverflow.com/questions/5503525/does-gridview-save-data-in-viewstate