How can I store a GridView cell value to a session variable?

Question

How would I store the value of a GridView's selected rows to a session variable?

Answer 1

From the codebehind file you will want to use something like this to access the underlying data item (MyDataItem) from the selected row.

MyDataItem item = (MyDataItem)GridView1.Rows[GridView1.SelectedIndex].DataItem;
Session["myItem"] = item;

Remember though, the gridview is already storing this data for you, so you may just want to access it from the GridView directly whenever you need it.

Answer 2

On a side note: can I stronly advise you NOT to use the session state.

Unless you are using it as a store where data is cached for the current user, which you can retrieve back at any time from e.g. a database.

If not, the "session" will come back and bite you. At some point there will be a user that leaves the browser open for longer time than your session lives (e.g. they get a telephone call, go out to lunch in a hurry, rush of to a meeting...). And when they return, they wish to complete what they are doing. And if you cannot restore all of your session data back at that point, you will either have to redirect your user to start over again (very annoying for your users), or you will have lost some information (very embarrasing), or the worst case, and most common case: your application will no longer work and crash (just plain: very bad).

It is a better approach to define small serializable objects that store your state (query parameters, selected items, etc) and use ASP.NET Viewstate to store that state across page requests. Note that most ASP.NET controls already use the viewstate to store their data. Then disable the Viewstate of your grids in the page, to vastly reduce the amount of data in your viewstate, and request the data upon each request (here it is safe to use the session or ASP.NET cache to improve performance of your application). You will have a much more robust and much more scalable application.

It is more work, but it will pay back very fast, and many times over.

Answer 3

ViewState only scope within one page. It's useful for postback problem, but not for cross-page problems. Session can handle both, but it has some limitations of security, lifetime, transmittion time... Depend on particular sittuation you can pick your right choice.