1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54
| NSURL *url = [NSURL URLWithString:@"https://developer.apple.com/library/ios/documentation/Cocoa/Reference/Foundation/ObjC_classic/FoundationObjC.pdf"];
// 1.创建 NSURLSessionConfiguration NSURLSessionConfiguration *backgroundConfiguration = [NSURLSessionConfiguration backgroundSessionConfigurationWithIdentifier: @"com.myapp.networking.background"];
// 2.创建 NSURLSession NSOperationQueue *operationQueue = [NSOperationQueue mainQueue];
NSURLSession *backgroundSession = [NSURLSession sessionWithConfiguration:backgroundConfiguration delegate:self delegateQueue:operationQueue];
// 3.创建 NSURLSessionDownloadTask NSURLSessionDownloadTask *downloadTask = [backgroundSession downloadTaskWithURL:url]; [downloadTask resume];
# prama mark - Delegate - (void)URLSession:(NSURLSession *)session downloadTask:(NSURLSessionDownloadTask *)downloadTask didWriteData:(int64_t)bytesWritten totalBytesWritten:(int64_t)totalBytesWritten totalBytesExpectedToWrite:(int64_t)totalBytesExpectedToWrite { NSLog(@"Session %@ download task %@ wrote an additional %lld bytes (total %lld bytes) out of an expected %lld bytes.n", session, downloadTask, bytesWritten, totalBytesWritten, totalBytesExpectedToWrite); } - (void)URLSession:(NSURLSession *)session downloadTask:(NSURLSessionDownloadTask *)downloadTask didResumeAtOffset:(int64_t)fileOffset expectedTotalBytes:(int64_t)expectedTotalBytes { NSLog(@"Session %@ download task %@ resumed at offset %lld bytes out of an expected %lld bytes.n", session, downloadTask, fileOffset, expectedTotalBytes); } - (void)URLSession:(NSURLSession *)session downloadTask:(NSURLSessionDownloadTask *)downloadTask didFinishDownloadingToURL:(NSURL *)location { NSLog(@"Session %@ download task %@ finished downloading to URL %@n", session, downloadTask, location); // Perform the completion handler for the current session self.completionHandlers[session.configuration.identifier](); // Open the downloaded file for reading NSError *readError = nil; NSFileHandle *fileHandle = [NSFileHandle fileHandleForReadingFromURL:location error:readError]; // ... // Move the file to a new URL NSFileManager *fileManager = [NSFileManager defaultManager]; NSURL *cacheDirectory = [[fileManager URLsForDirectory:NSCachesDirectory inDomains:NSUserDomainMask] firstObject]; NSError *moveError = nil; if ([fileManager moveItemAtURL:location toURL:cacheDirectory error:moveError]) { // ... } }
|