I'll answer my own question.  FINAL ANSWER!

 You need to set the rowindex on the rowdatabound event.

Protected Sub gvResults_RowDataBound(ByVal sender As Object, ByVal e As GridViewRowEventArgs) Handles gvResults.RowDataBound

End Sub

 Then you can access the CommandArgument in the RowCommand

Protected Sub gvResults_RowCommand(ByVal sender As Object, ByVal e As System.Web.UI.WebControls.GridViewCommandEventArgs) Handles gvResults.RowCommand

' Retrieve the row that contains the button clicked

' by the user from the Rows collection.

Dim row As GridViewRow = gvResults.Rows(index)

End Sub 

Hi i am doing the exact same thing. I retrieve a non primary key from the datakeys. I works great

 but

when i implement an update method to the gridview i have an issue.

Well the column i have put in the datakeys collection is added to the parameters  passed to the object_datasource update function as "original_NAME OF THE COLUMN"

 and when i click on the updated button, i get an error

 
Object of type 'System.DBNull' cannot be converted to type 'System.Int32'.

it looks like thoses original_... values are not set properly.

can someone help me please  ?

thanks

Dan

 

THanks.

 Check this article, it resumes this post quite well. http://msdn2.microsoft.com/en-us/library/system.web.ui.webcontrols.buttonfield.aspx

Is the above code to be put in the GridView1_RowCommand method or in someother method? Also, would the same code apply when we have paging and the the row selected happens to be, say, row 4 on page 3? If, possible could you please illustrate the code? I hope you will not mind my asking so many questions as I am a newbie. Thanks.

Thanks, I just need this procedure.  One point to note is that I need to add the non-primarykey field in datakeynames. 

Dim MyKey as integer = CType(grd.SelectedDataKey(0), Integer)
Dim index As Integer = grd.SelectedIndex
Dim AnotherField as string = grd.DataKeys(index).Item("AnotherFieldName").ToString()
 

Also, in your aspx file, remember to add this:
DataKeyNames="PrimaryKeyField,AnotherFieldName"

See this post http://forums.asp.net/p/1168036/2214253.aspx#2214253

 or if you cant be bothered to click, read this:

---- 

CommandArgument='<%# GridView1.Rows.Count.ToString() %>' 

 I like MSchumacher´s solution for this and I have used the same method, previously I achieved it using the RowDataBound event

protected void _grid_RowDataBound(object sender, GridViewRowEventsArgs e) {

        if (e.Row.RowType == DataControlRowType.DataRow) {

              //Button button = e.Row.Cells[0].FindControls("btnEdit") as ImageButton;

             button.CommandArgument = e.Row.RowIndex.ToString()

      }

}

And how is the selectParameter for the SQLdatasource will be?

 For the single data key is like this :

How is the the 2 data keys will be?

DataKeyNames can be anything it doesn't have to be a primary key. The fact that it is most of the time is a convention. You can put any amount of fields in DataKeyNames and access the values using:

GridView.DataKeys[rowIndex].Values[fieldName]

OR

GridView.DataKeys[rowIndex].Values[fieldIndex]

Checkout my blog post on extracting values from data controls.

Its just simple

just use this 

GridView.DataKeys[Rowindex].Values[coloumn index]

here the row index and coloumn index are jus two names. you have to give the value of row index and colomn index

this works in C#

 You can retrive non key value from e.Row.DataItem in/after grid databound event.