Discussion
議論
By default, Progress
objects aren’t pausable.
You typically use this property to communicate whether controls for pausing appear in a progress-reporting user interface. Progress
itself doesn’t do anything with this property other than help pass the value from progress reporters to progress observers.
If an NSProgress
is pausable, implement the ability to pause either by setting a block for the pausingHandler
property, or by polling the isPaused
property periodically while performing the relevant work.
It’s valid for the value of this property to change during the lifetime of an NSProgress
object. By default, NSProgress
is KVO-compliant for this property. It sends notifications on the same thread that updates the property.