Instance Method

downloadTask(withResumeData:)

Creates a download task to resume a previously canceled or failed download.

Declaration

func downloadTask(withResumeData resumeData: Data) -> URLSessionDownloadTask

Parameters

resumeData

A data object that provides the data necessary to resume a download.

Return Value

The new session download task.

Discussion

After you create the task, you must start it by calling its resume() method.

This method is equivalent to the downloadTask(withResumeData:completionHandler:) with a nil completion handler. For detailed usage information, including ways to obtain a resume data object, see that method.

See Also

Adding Download Tasks to a Session

func downloadTask(with: URL)

Creates a download task that retrieves the contents of the specified URL and saves the results to a file.

func downloadTask(with: URL, completionHandler: (URL?, URLResponse?, Error?) -> Void)

Creates a download task that retrieves the contents of the specified URL, saves the results to a file, and calls a handler upon completion. The task bypasses calls to delegate methods for response and data delivery, and instead provides any resulting NSData, URLResponse, and NSError objects inside the completion handler. Delegate methods for handling authentication challenges, however, are still called.

func downloadTask(with: URLRequest)

Creates a download task that retrieves the contents of a URL based on the specified URL request object and saves the results to a file.

func downloadTask(with: URLRequest, completionHandler: (URL?, URLResponse?, Error?) -> Void)

Creates a download task that retrieves the contents of a URL based on the specified URL request object, saves the results to a file, and calls a handler upon completion. The task bypasses calls to delegate methods for response and data delivery, and instead provides any resulting NSURL, URLResponse, and NSError objects inside the completion handler. Delegate methods for handling authentication challenges, however, are still called.

func downloadTask(withResumeData: Data, completionHandler: (URL?, URLResponse?, Error?) -> Void)

Creates a download task to resume a previously canceled or failed download and calls a handler upon completion. The task bypasses calls to delegate methods for response and data delivery, and instead provides any resulting NSURL, URLResponse, and NSError objects inside the completion handler. Delegate methods for handling authentication challenges, however, are still called.

class URLSessionDownloadTask

A URL session task that stores downloaded data to file.

protocol URLSessionDownloadDelegate

The NSURLSessionDownloadDelegate protocol defines delegate methods that you should implement when using URLSession download tasks. In addition to these methods, be sure to implement the methods in the URLSessionTaskDelegate and URLSessionDelegate protocols to handle events common to all task types and session-level events, respectively.