BootstrapGridViewContextMenuInitializeEventArgs Class

<dx:BootstrapGridView runat="server" 
    OnContextMenuInitialize="GridViewContextMenu_ContextMenuInitialize">
    <SettingsContextMenu Enabled="true" />
    //...
</dx:BootstrapGridView>

protected void GridViewContextMenu_ContextMenuInitialize(object sender, BootstrapGridViewContextMenuInitializeEventArgs e) {
    if(e.MenuType == GridViewContextMenuType.Rows) {
        var item = e.CreateItem("Export", "Export");
        item.BeginGroup = true;

        e.ContextMenu.Items.Insert(e.ContextMenu.Items.IndexOfCommand(GridViewContextMenuCommand.Refresh), item);
        item.Items.Add(e.CreateItem(GridViewContextMenuCommand.ExportToPdf));
        //...
    }
}