Add a Column to a DataGrid

infernokodiak · January 5th, 2006, 05:52 PM

Is it possible to add a column to a DataGrid. Say for instance I have two columns Quantity and Cost that I would like to multiply the two to get total and display within the DataGrid.

In the actual data I'm using (its for a budget preparation project), I would like to generate 3 columns in addition to the ones already sent back from the database, each with several calculations on the data within each row.

I know I can create a stored procedure that will run the calculations but I would like to know if anyone knows if its possible within ASP.NET's DataGrid or 2.0's server controls.

John

planoie · January 6th, 2006, 10:08 AM

You have a couple options:

Use a data structure that you can easily modify such as a DataTable. After loading the data, you could add columns, spin thru the data, do the calculations and put the results into the new columns. Then bind the whole lot to the datagrid.

Alternatively, you could just add some extra template columns to the datagrid, and write databinding syntax that does the calculations right in the control markup.

-Peter

infernokodiak · January 6th, 2006, 01:50 PM

Thanks planoie!

Ok so I'll explore use of the DataTable.

On the possible 2nd option, would you have any samples or can you write a simple example of databinding syntax that does calculations in the control markup? Is this solely a 2.0 option?

John

planoie · January 13th, 2006, 05:25 PM

<%# 1 + 1 %>

Seriously though, you can put pratically anything inside data binding syntax. If your data item were numeric:

<%# Container.DataItem * 12 %>

If it is a string:

<%# Container.DataItem + "Hello World" %>

and so on. To calculate a result of some fields as another example then this might work:

<#% DataBinder.Eval(Container.DataItem, "Qty") * DataBinder.Eval(Container.DataItem, "PricePerItem") %>

-Peter

Imar · January 13th, 2006, 05:58 PM

Just don't forget that DataBinder.Eval uses reflection so it's always slower than strongly typed access. Where appropriate, cast your objects to proper types before you access its properties.

Check out this link for some details:

http://www.dotnetslackers.com/_NET/r...n_ASP_NET.aspx

Imar
---------------------------------------
Imar Spaanjaars
Everyone is unique, except for me.

mehdi62b · January 15th, 2006, 01:06 AM

Quote:

quote:Originally posted by infernokodiak
Is it possible to add a column to a DataGrid. Say for instance I have two columns Quantity and Cost that I would like to multiply the two to get total and display within the DataGrid.

its possible to de them in code-behind...

Code:

DataColumn dtc=new DataColumn("Sum",typeof(int));

Code:

   dtc2.Expression="Quantity * Cost";
   dataTable.Columns.Add(dtc);

_____________
Mehdi.
software student.

mehdi62b · January 15th, 2006, 01:11 AM

Quote:

quote:Originally posted by infernokodiak
Is it possible to add a column to a DataGrid. Say for instance I have two columns Quantity and Cost that I would like to multiply the two to get total and display within the DataGrid.

you can do it in code-behind

Code:

DataColumn dtc=new DataColumn("Sum",typeof(int));

Code:

   dtc.Expression="Quantity * Cost";
   dataTable.Columns.Add(dtc);

_____________
Mehdi.
software student.

infernokodiak · January 18th, 2006, 04:06 PM

Appreciate all the input. Learning to work with the DataGrid has been a fun experience! though frustrating at times. :)