- iOS 7.0+
- macOS 10.9+
- Mac Catalyst 13.0+Beta
- tvOS 9.0+
- watchOS 2.0+
The total number of units of work to be carried out.
The initializer is passed the current progress object, if there is one, and the value of the
total property is set.
In many cases you can simply precede code that does a substantial amount of work with an invocation of this method, then repeatedly set the
cancelled property in the loop that does the work.
You can invoke this method on one thread and then message the returned
NSProgress on another thread. For example, you can capture the created progress instance in a block that you pass to
dispatch. In that block you can invoke methods like
resign, and set the
cancelled properties as work is carried out.