e mërkurë, 19 shtator 2007

Add rows to asp table web control dynamically

Came across this 'constraint' recently and was amazed to find not much solution exist in .net world for this.

Requirement: Add rows dynamically to an asp table, web control(or say dynamically you want to keep on adding controls on click / some event)

Issue: I was able to add row but previously added row 'vanishes' from UI

Reason: Viewstate of dynamically created control is lost on next post back


Added a session to store state of table and to render/recreate the control on post back

code as below in page_load event

if (Session["rowList"] == null)
//No row list, Create it.
rowList = new List();
rowList = (List)Session["rowList"];
//Recreate the table. (Prevents loosing data already entered into textboxes.)

There is an addrow method called on click (/ any event you like )
You have to add our newly formed row to our row List as below.

Then save our Row List on to the session
Session.Add("rowList", rowList);
Call the DisplayTable();

Finally recreating table as below in DisplayTable function

protected void DisplayTable()
//Run through the row list, and add each one to the Table's Row Collection.
foreach (TableRow tr in rowList)

Any other suggestion / idea you have please post it here....coz i am still not convinced by this idea :(

5 komente:

Anonymous tha...

Funcionou legal. Por enquanto essa foi a melhor solução que encontrei.

borocin tha...

You really should post the whole code, not just glimpse of it. This wasn't any help at all partly because code and explanations like:

Then save our Row List on to the session
Session.Add("rowList", rowList);
Call the DisplayTable();

First of all the rowList is only locally created in the PageLoad-part as you explain in the first part. So how are you going to add anything to it from a e.g. OnButtonClick-event?

Anyways, I am sure this will be helpful with more of your code, and not just some notes...

Alex tha...

A better way is to keep track of how many of the dynamic controls you have in a Session variable. And then override OnInit() and recreate the objects within.

The page will keep track of the session state automatically.

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santhosh tha...

Perfectly useful for me , I appreciate the way it is described. Thanks so much..Santhosh