GridView sort by a column whose header is dynamically created

[gnewsgroup]

I have a GridView, in which the header of one column changes depending
on the selected value of a DropDownList outside of this GridView.

I did this dynamic header through

protected void GridView1_RowCreated(object sender,
GridViewRowEventArgs e)
{
if (e.Row.RowType == DataControlRowType.Header)
{
e.Row.Cells[5].Text =
myDropDownList.SelectedValue;
}
}

In the declaration of this GridView, I have

AllowSorting="true"

and of course I have a Sorting event handler.

Every column is sortable except this column with the dynamic header.
If assign a static value to this header and remove this RowCreated
event handler, this column becomes sortable, too.

So, the question is: How can I make the column with a dynamic header
sortable?

 

[Cowboy \(Gregory A. Beamer\)]

It is essentially the same as sorting with a non-dynamically created header,
except you have to control the sort. For a simple sort, you can use a
DataView to bind and set up the sort there. With this form of sort, you can
cache the data, most likely in ViewState, although there are applications
where this is not acceptable.

If you also need paging, you will have to write custom software to do this
and will probably have to retrieve the data each time there is a sort so you
can get a pointer to figure out start and end of the page.

If you want to see how Microsoft does it, you can use Reflector on the .NET
assemblies or, in VS 2008, step into the code. Both can give you a clue of
how MS accomplishes sorting.

Here's a couple of articles:
http://lakshmik.blogspot.com/2006/06/aspnet-20-custom-paging-and-custom.html
http://imar.spaanjaars.com/QuickDocId.aspx?quickdoc=428

I am kind of fond of the idea in the second one, although I have not tried
it. Binding with generics would take a bit of work to massage the data
intitially, but the benefits outweigh the extra work.

 

[gnewsgroup]

It is essentially the same as sorting with a non-dynamically createdheader,
except you have to control the sort. For a simple sort, you can use a
DataView to bind and set up the sort there. With this form of sort, you can
cache the data, most likely in ViewState, although there are applications
where this is not acceptable.

If you also need paging, you will have to write custom software to do this
and will probably have to retrieve the data each time there is a sort so you
can get a pointer to figure out start and end of the page.

If you want to see how Microsoft does it, you can use Reflector on the .NET
assemblies or, in VS 2008, step into the code. Both can give you a clue of
how MS accomplishes sorting.

Here's a couple of articles:http://lakshmik.blogspot.com/2006/0...r.spaanjaars.com/QuickDocId.aspx?quickdoc=428

I am kind of fond of the idea in the second one, although I have not tried
it. Binding with generics would take a bit of work to massage the data
intitially, but the benefits outweigh the extra work.

"

Thank you very much for the references. The problem for me right now
is that the dynamically created header isn't even clickable, unlike
other static header, which you can click and sort.

 

[AlphaQuam]

I ran into this same problem. Originally, I was using the Row.Cells collection as well. I would suggest trying the following...

GridView1.Columns[5].HeaderText = myDropDownList.SelectedValue;

Be careful of when you make this assignment. I'm not sure what you're binding your GridView to, but changing the header text when using a LinqDataSource after its OnSelecting event (such as in the GridView's OnDataBinding event) will cause that event to fire again after the headers have been updated. Obviously, this could cause some serious performance issues, as well as other potential problems.

 

[bigal]

It appears somebody fixed your problem AlphaQuam - of not being able to post. Please enable your private messages so people may contact you and welcome to the Velocity Reviews forums. :driver: