You could modify the snippet so instead of iterating e.Rows you will iterate the WebGrid datasource or you will need to requery the data if the WebGrid do not cache the data.

Here is the updated snippet that will iterate the WebGrid datasource, in my scenario the DataSource is a DataTable:

protected void wgTest_CustomAggregate(object sender, ISNet.WebUI.WebGrid.CustomAggregateArgs e)
{
    if (e.Column.DataMember == "Date")
    {
        DataTable dtSource = (DataTable)wgTest.GetCachedDataSource();
        Double sumVal = 0;
        Double sumValX = 0;
        for (int i = 0; i < dtSource.Rows.Count; i++)
        {
            sumVal += (Double)dtSource.Rows[i]["Value"];

            sumValX += (Double)dtSource.Rows[i]["ValueX"];
        }

        e.AggregateResult = sumValX + " / " + sumVal + " : " + ((Double)(sumValX / sumVal)).ToString("#.#0");
    }
}

The text dump is the ophuscated javascript that used by our component. Based on the generated date of the javascript, 8/7/2009, it indicate that you are still older version of our resources.

If you are using WebGrid 7 build 400 please use WebUI Framewok 3 build 750 and make sure you already update your WebGrid resources. In order to update the WebUI Framework please copy these files to your project bin folder:
- ISNet.dll
- ISNet.WebUI.dll
- ISNet.WebUI.Resources.dll (If you are using SmartWebResources)

If you are not using SmartWebResources you will need to copy the latest WebUI Framework & WebGrid javascript to your CommonLibrary virtual directory folder.

I have created a simple sample using the scenario you described. After selecting a row in the WebGrid #1, WebGrid #2 will load a new data source.

I have done some small modification in the technique you used in the attached sample. However, I think you could still achieve the desired result.

In order to preserve the column structure and order in RefreshAll using your approach, you will need to add the column as the order in the previous WebGrid not by setting the position property. Here is the modified snippet of the PrepareDataBinding event handler:

protected void WebGrid1_PrepareDataBinding1(object sender, ISNet.WebUI.WebGrid.DataSourceEventArgs e)
{
    if (!IsPostBack || WebGrid1.FlyPostBackAction == PostBackAction.RefreshAll)
    {
        System.Collections.Generic.Dictionary<string, Unit> columnSize = new System.Collections.Generic.Dictionary<string, Unit>();
        System.Collections.Generic.Dictionary<string, int> columnPosition = new System.Collections.Generic.Dictionary<string, int>();

        for (int i = 0; i < WebGrid1.RootTable.Columns.Count; i++)
        {
            columnSize.Add(WebGrid1.RootTable.Columns[i].Name, WebGrid1.RootTable.Columns[i].Width);
            columnPosition.Add(WebGrid1.RootTable.Columns[i].Name, WebGrid1.RootTable.Columns[i].Position);
        }

        if (!(columnPosition.Count > 0))
        {
            columnPosition.Add("Application",0);
            columnPosition.Add("Workflow", 1);
            columnPosition.Add("ActivityDisplayName", 2);
        }

        WebGrid1.RootTable.Columns.Clear();

        foreach (string key in columnPosition.Keys)
        {
            WebGridColumn Col2 = new WebGridColumn();
            Col2.Name = key;
            Col2.Bound = true;
            Col2.DataMember = key;

            WebGrid1.RootTable.Columns.Add(Col2);
            
            if (columnSize.Count > 0)
                Col2.Width = columnSize[Col2.Name];
        }
    }
    
    WebGrid1.RootTable.DataMember = "skworkitem";
}

Since the original question of this thread has been solved, next time please create a new thread if you have a new question.

WebScheduler have a method to refresh the data programatically using the RefreshAll client side function. Here is the snippet:

function RefreshScheduler() {
    var sched = ISGetObject("WebScheduler1");

    sched.RefreshAll();
}