public delegate void ProgressEventHandler(
	Object sender,
	OngoingOperation ongoingOperation,
	double progress,
	ref bool cancel
)

Public Delegate Sub ProgressEventHandler ( 
	sender As Object,
	ongoingOperation As OngoingOperation,
	progress As Double,
	ByRef cancel As Boolean
)

public delegate void ProgressEventHandler(
	Object^ sender, 
	OngoingOperation ongoingOperation, 
	double progress, 
	bool% cancel
)

type ProgressEventHandler = 
    delegate of 
        sender : Object * 
        ongoingOperation : OngoingOperation * 
        progress : float * 
        cancel : bool byref -> unit