The OnLoadReportParameters event passes a list of Parameter elements that can be reordered or modified before they are sent to the client for display. Called when report parameters are loaded, but before any processing has occurred. By default, parameters are sorted alphabetically by name.
For custom code the args array is structured as follows:
args is contains one object, a list of Parameter elements.
For .NET Assemblies the method signature is as follows:
void EventHandlerName(SessionInfo sessionInfo, List<Parameter> parameters)
The event has a void return value.