Is there an easy way to get a GridView row given a DataKey?  Right now, I'm
looping through each row of the GridView and checking its DataKey, but it
seems that there must be a better way.

Thanks!
Greg

Greg,

I have found that I cannot often rely on the DataKey.  Instead when I
do have a button in a GridView I set the CommandArgument for the button
to the identifier for the data in that row.  Hopefully that will be a
primary key which you can use for the actions you plan to take.

I set the CommandArgument (and CommandName to provide some context) in
the RowCreated event which is called for each row.  You can access the
data for that row with e.Item.DataItem which will not be null when the
GridView is first bound.  But on PostBacks you will find null
references since only the bound values in the related controls are
persisted through ViewState.

Brennan Stehling
http://brennan.offwhite.net/blog/

Greg wrote:
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Brennan,

Thanks, that's an interesting idea.  I've had problems with the DataKey
before myself.  Another page I worked on recently had an empty DataKeys
collection after posting back.  I ended up having to rebind the grid after
the postback in order to get the DataKey, but I think your solution would
have been better.

In this case though, I don't think it will work for me.  What I'm working on
now is a wizard, where one of the steps has a gridview where each row has a
text column filled from the database, plus a couple of check boxes.  The
check boxes are being checked/unchecked from an object in the viewstate when
the user gets to that step, so if the user returns to the step, the changes
are still there, but they aren't saved to the database until the end of the
wizard.  (There may be a better way to do this, but I don't want to make this
post even longer with too many details.)  So basically, I know the DataKey of
the rows where I need to check boxes, and was hoping there's an easy way to
get the row without looping through each row to see if the DataKey matches.

But I like your suggestion.  That answers the question I had earlier, and
will ultimately be more useful than saving 10 lines of code looping through
rows in a GridView.

Thank you,
Greg


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hay, im having the same problem

im trying to retrive the primary key of the record in the grid view. i've set the datakeynames="id" and the OnRowCommand to refer to my vb procedure.


        Dim index As Integer = Convert.ToInt32(e.CommandArgument)

        Dim id As Integer = CType(GridView1.DataKeys(index).Values("Id"), Integer)

i just seem to be getting a null value.

im trying to populate the record data into freetextbox.

thankz

Ko$tA,

That appears to be working code, but I have had trouble making the
DataKey work reliably.  Instead of placing the index in the
CommandArgument, use the value of the primary key.  That is what I use.

In ASP.NET 1.1 it was common to place a column in the DataGrid for the
primary key, but the Visible property on the column is set to false.
But when I try that in ASP.NET 2.0 it does not bind the column.  That
is why I am now using the CommandArgument on a button.

What may fix this situation is using a typed DataSet.  I often bind a
collection of business objects instead of typed DataSets as is highly
suggested by MSDN documentation.  Using a typed DataSet should identify
the primary key which is used for the DataKey.

Brennan Stehling
http://brennan.offwhite.net/blog/

Ko$tA wrote:
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