A task, like downloading a specific resource, performed in a URL session.
- iOS 7.0+
- macOS 10.9+
- tvOS 9.0+
- watchOS 2.0+
NSURLSession class is the base class for tasks in a URL session. Tasks are always part of a session; you create a task by calling one of the task creation methods on a
NSURLSession instance. The method you call determines the type of task.
dataand related methods to create
Task With URL:
NSURLSessioninstances. Data tasks request a resource, returning the server’s response as one or more
NSDataobjects in memory. They are supported in default, ephemeral, and shared sessions, but are not supported in background sessions.
uploadand related methods to create
Task With Request: from Data:
NSURLSessioninstances. Upload tasks are like data tasks, except that they make it easier to provide a request body so you can upload data before retrieving the server’s response. Additionally, upload tasks are supported in background sessions.
downloadand related methods to create
Task With URL:
NSURLSessioninstances. Download tasks download a resource directly to a file on disk. Download tasks are supported in any type of session.
Task With Host Name: port:
Task With Net Service:
NSURLSessioninstances. Stream tasks establish a TCP/IP connection from a host name and port or a net service object.
After you create a task, you start it by calling its
resume method. The session then maintains a strong reference to the task until the request finishes or fails; you don’t need to maintain a reference to the task unless it’s useful for your app’s internal bookkeeping.