网络NSURLSession

简单下载图片

dispatch_queue_t queue =dispatch_queue_create(NULL, DISPATCH_QUEUE_CONCURRENT);

dispatch_async(queue, ^{

//1.获取网址字符串

NSString * urlString = @"http://www.bz55.com/uploads/allimg/121230/1-121230094954.jpg";

//2.NSString->NSURL

NSURL * url = [NSURL URLWithString:urlString];

//3.同步下载

NSData * data = [NSData dataWithContentsOfURL:url];

UIImage * image = [UIImage imageWithData:data];

dispatch_sync(dispatch_get_main_queue(), ^{

self.view.backgroundColor = [UIColor colorWithPatternImage:image];

});

});

NSURL

NSString * urlString = @"http://www.bz55.com/uploads/allimg/121230/1-121230094954.jpg";

NSURL * url = [NSURL URLWithString:urlString];

NSLog(@"Scheme: %@", [url scheme]);

NSLog(@"Host: %@", [url host]);

NSLog(@"Port: %@", [url port]);

NSLog(@"Path: %@", [url path]);

NSLog(@"Relative path: %@", [url relativePath]);

NSLog(@"Path components as array: %@", [url pathComponents]);

NSURLSession

NSString * urlString = @"http://www.bz55.com/uploads/allimg/121230/1-121230094954.jpg";

NSURL * url = [NSURL URLWithString:urlString];

NSURLSessionConfiguration * defaultConfig = [NSURLSessionConfiguration defaultSessionConfiguration];

defaultConfig.timeoutIntervalForRequest = 20;

defaultConfig.timeoutIntervalForResource = 60;

defaultConfig.allowsCellularAccess = NO;//只能用wifi

NSURLSession * session = [NSURLSession sessionWithConfiguration:defaultConfig];

NSURLSessionDataTask * datatask =[session dataTaskWithURL:url completionHandler:^(NSData * _Nullable data, NSURLResponse * _Nullable response, NSError * _Nullable error) {

NSLog(@"%@",[NSThread currentThread]);

}];

[datatask resume];