<CategoryAttribute("Behavior")>
<DescriptionAttribute()>
Public Event ButtonClick As ButtonClickEventHandler

Dim instance As WebGrid
Dim handler As ButtonClickEventHandler
 
AddHandler instance.ButtonClick, handler

[CategoryAttribute("Behavior")]
[DescriptionAttribute()]
public event ButtonClickEventHandler ButtonClick

public event ButtonClick: ButtonClickEventHandler; 

In JScript, you can handle the events defined by another class, but you cannot define your own.

[CategoryAttribute("Behavior")]
[DescriptionAttribute()]
public: __event ButtonClickEventHandler* ButtonClick

[CategoryAttribute("Behavior")]
[DescriptionAttribute()]
public:
event ButtonClickEventHandler^ ButtonClick

private void WebGrid1_InitializeDataSource(object sender, ISNet.WebUI.WebGrid.DataSourceEventArgs e)
{
    oleDbDataAdapter1.Fill(dsNorthWindEnt1.Customers);
    e.DataSource = dsNorthWindEnt1;
}

private void WebGrid1_ButtonClick(object sender, ISNet.WebUI.WebGrid.ButtonEventArgs e)
{
    if (e.Column.Name == "btnCol1") 
    {
       oleDbConnection1.Open();
       OleDbCommand cmd = new OleDbCommand("select count(*) from [orders] where customerid='" + e.CellValue + "'", oleDbConnection1);
       int total = int.Parse( cmd.ExecuteScalar().ToString() );
       oleDbConnection1.Close();

       WebGrid1.ClientAction.Alert("Total order for '" + e.CellValue + "' is : " + total.ToString());
    }
}

<script language="javascript">
function Grid1_ButtonClick(gridId, tblName, colName, cellValue) 
{
   alert("Clicked button is : " + colName + "\nThe value is : " + cellValue);
   
   // set return false to cancel postback
   return true;
}
</script>