Could you please post the code on how to call it on the aspx as well as code behind. What the events and how do we should the Expand + sign and place a FormView in the child.

Thanks

You might want to consider using the InitializeRow event, since it will fire for each row as it is bound, rather then the DataBound().

Awesome, thank you for posting this, it helped solved a problem I was not able to solve.

Thank you all people, i found a solution, a event of the grid, named DataBound. This is the sample code:

        protected void UltraWebGrid1_DataBound(object sender, EventArgs e)
        {
            UltraWebGrid1.Bands.Add(new UltraGridBand());

            foreach (UltraGridRow row in UltraWebGrid1.Rows)
                row.ShowExpand = true;

        }

And that's all, finally my grid show the plus image to open sub levels....

'UltraWebGrid1_InitializeDataSource' is not supposed to be used under the binding mode. it's an improved and integrated Ajax-Engine. if you really need to use it,just to find some stuff about the page lifecycle of UltraWebGrid and  'invokeXmlHttpRequest'.for example:

on client side:
function remote_request(gn) {
    var g = igtbl_getGridById(gn);
    var param=[;
            for (int i = 0; i < 21; i++){
                param[param.length]=i + 1;
            }
    g.invokeXmlHttpRequest(g.eReqType.Custom, null, param.join(','))
}

on server side:
         ...UltraWebGrid1_XmlHTTPRequest...
                If(e.Type==XmlHTTPRequestType.Custom )
                {
                        //do sth to read the submited param and and add the datarow one by one
                }

IMO,it's easier to use some standard ajax  gallery to instead of 'UltraWebGrid1_XmlHTTPRequest',such as mootool,pototype...etc.

good luck.