init(totalUnitCount:parent:pendingUnitCount:)
Creates a progress instance for the specified progress object with a unit count that’s a portion of the containing object’s total unit count.
Declaration
init(totalUnitCount unitCount: Int64, parent: Progress, pendingUnitCount portionOfParentTotalUnitCount: Int64)Parameters
- unitCount:
The total number of units of work to assign to the progress instance.
- parent:
The containing progress object for the created Progress object.
- portionOfParentTotalUnitCount:
The unit count for the progress object.
Discussion
Use this method to initialize a progress object with a specified containing progress object and unit count.
In many cases, you can precede code that does a substantial amount of work with an invocation of this method, then repeatedly set the completedUnitCount or isCancelled property in the loop that does the work.
You can invoke this method on one thread and then message the returned Progress on another thread. For example, you can capture the created progress instance in a block that you pass to dispatch_async. In that block, you can invoke methods like becomeCurrent(withPendingUnitCount:) or resignCurrent(), and set the completedUnitCount or isCancelled properties as your app finishes its work.