// // ViewController.m // NSURLSession代理简介 #import "ViewController.h" @interface ViewController ()<NSURLSessionDataDelegate> @end @implementation ViewController - (void)viewDidLoad { [super viewDidLoad]; } //这是为了测试而建立的点击屏幕事件。 -(void)touchesBegan:(NSSet<UITouch *> *)touches withEvent:(UIEvent *)event{ //代理 测试 NSURL * url = [NSURL URLWithString:@"http://localhost/login.php?username=haha&password=123"]; //创建自定义Session NSURLSession * session = [NSURLSession sessionWithConfiguration:[NSURLSessionConfiguration defaultSessionConfiguration] delegate:self delegateQueue:[[NSOperationQueue alloc]init]]; NSURLSessionTask * task = [session dataTaskWithURL:url]; //开启任务 [task resume]; } #pragma mark - deleDate //接受到服务器响应 -(void)URLSession:(NSURLSession *)session dataTask:(NSURLSessionDataTask *)dataTask didReceiveResponse:(NSURLResponse *)response completionHandler:(void (^)(NSURLSessionResponseDisposition))completionHandler { //__FUNCTION__ c语言字符串用s NSLog(@"%s",__FUNCTION__); //允许服务器回传数据 completionHandler(NSURLSessionResponseAllow); } //接受服务器回传的数据可能执行多次 -(void)URLSession:(NSURLSession *)session dataTask:(NSURLSessionDataTask *)dataTask didReceiveData:(NSData *)data{ NSLog(@"%@",[[NSString alloc]initWithData:data encoding:NSUTF8StringEncoding]); } //请求成功或者失败 -(void)URLSession:(NSURLSession *)session didBecomeInvalidWithError:(NSError *)error{ NSLog(@"%@",error); } @end
上面简单介绍了一下
然后我们来看一个demo
其中下载文件的地址，读者可以自己配置
1 // 2 // ViewController.m 3 // NSURLSession大文件下载 4 // 5 // 6 7 #import "ViewController.h" 8 9 @interface ViewController ()<NSURLSessionDownloadDelegate> 10 11 @property (nonatomic, strong) NSURLSessionDownloadTask * task; 12 13 @property (nonatomic, strong) NSData * resumeData; 14 15 @property (nonatomic, strong) NSURLSession * session; 16 17 @end 18 19 @implementation ViewController 20 21 22 - (IBAction)start:(id)sender { 23 24 NSURLSession * session = [NSURLSession sessionWithConfiguration:[NSURLSessionConfiguration defaultSessionConfiguration] delegate:self delegateQueue:[[NSOperationQueue alloc] init]]; 25 26 self.session = session; 27 28 self.task = [session downloadTaskWithURL:[NSURL URLWithString:[@"http://192.168.1.200/DOM解析.mp4"stringByAddingPercentEscapesUsingEncoding:NSUTF8StringEncoding]]]; 29 30 [self.task resume]; 31 } 32 33 34 - (IBAction)pause:(id)sender { 35 36 //暂停就是将任务挂起 37 38 [self.task cancelByProducingResumeData:^(NSData * _Nullable resumeData) { 39 40 //保存已下载的数据 41 self.resumeData = resumeData; 42 }]; 43 } 44 45 - (IBAction)resume:(id)sender { 46 47 //可以使用ResumeData创建任务 48 49 self.task = [self.session downloadTaskWithResumeData:self.resumeData]; 50 51 //开启继续下载 52 [self.task resume]; 53 54 } 55 56 - (void)viewDidLoad { 57 [super viewDidLoad]; 58 // Do any additional setup after loading the view, typically from a nib. 59 60 NSLog(@"%@",NSSearchPathForDirectoriesInDomains(9, 1, 1)); 61 } 62 63 64 /* 65 66 监测临时文件下载的数据大小，当每次写入临时文件时，就会调用一次 67 68 bytesWritten 单次写入多少 69 totalBytesWritten 已经写入了多少 70 totalBytesExpectedToWrite 文件总大小 71 72 */ 73 74 - (void)URLSession:(NSURLSession *)session downloadTask:(NSURLSessionDownloadTask *)downloadTask 75 didWriteData:(int64_t)bytesWritten 76 totalBytesWritten:(int64_t)totalBytesWritten 77 totalBytesExpectedToWrite:(int64_t)totalBytesExpectedToWrite { 78 79 //打印下载百分比 80 NSLog(@"%f",totalBytesWritten * 1.0 / totalBytesExpectedToWrite); 81 82 } 83 84 //下载完成 85 86 - (void)URLSession:(NSURLSession *)session downloadTask:(NSURLSessionDownloadTask *)downloadTask 87 didFinishDownloadingToURL:(NSURL *)location { 88 89 90 NSString * cachesPath = [[NSSearchPathForDirectoriesInDomains(NSCachesDirectory, NSUserDomainMask, YES) lastObject] stringByAppendingPathComponent:downloadTask.response.suggestedFilename]; 91 92 NSFileManager * mgr = [NSFileManager defaultManager]; 93 94 [mgr moveItemAtURL:location toURL:[NSURL fileURLWithPath:cachesPath] error:NULL]; 95 96 } 97 98 - (void)URLSession:(NSURLSession *)session task:(NSURLSessionTask *)task didCompleteWithError:(NSError *)error { 99 100 NSLog(@"%@",error); 101 } 102 103 - (void)didReceiveMemoryWarning { 104 [super didReceiveMemoryWarning]; 105 // Dispose of any resources that can be recreated. 106 } 107 108 @end