1.NSURLSessionDataTask
1 // 确定URL 2 NSString *urlStr = @"http://localhost/试试看"; 3 urlStr = [urlStr stringByAddingPercentEscapesUsingEncoding:NSUTF8StringEncoding]; 4 NSURL *url = [NSURL URLWithString:urlStr]; 5 6 // 确定request 7 NSMutableURLRequest *request = [NSMutableURLRequest requestWithURL:url cachePolicy:0 timeoutInterval:2.0f]; 8 9 // 确定会话 10 NSURLSession *session = [NSURLSession sharedSession]; 11 12 // 由会话生成任务 13 NSURLSessionDataTask *dataTask = [session dataTaskWithRequest:request completionHandler:^(NSData *data, NSURLResponse *response, NSError *error) { 14 NSLog(@"response-- %@",response); 15 NSLog(@"data--%@",data); 16 17 // 刷新UI,一定要返回主线程去刷新 18 dispatch_async(dispatch_get_main_queue(), ^{ 19 [self.imageView setImage:[UIImage imageWithData:data]]; 20 }); 21 22 }]; 23 24 [dataTask resume];
2.NSURLSessionDownloadTask实现简单的下载功能
1 // 确定URL 2 NSString *urlStr = @"http://localhost/试试看"; 3 urlStr = [urlStr stringByAddingPercentEscapesUsingEncoding:NSUTF8StringEncoding]; 4 NSURL *url = [NSURL URLWithString:urlStr]; 5 6 // 确定request 7 NSMutableURLRequest *request = [NSMutableURLRequest requestWithURL:url cachePolicy:0 timeoutInterval:2.0f]; 8 9 // 确定会话 10 NSURLSession *session = [NSURLSession sharedSession]; 11 12 // 由会话生成任务 13 NSURLSessionDownloadTask *downloadTask = [session downloadTaskWithRequest:request completionHandler:^(NSURL *location, NSURLResponse *response, NSError *error) { 14 // 从tmp中拷贝文件到cache 15 NSString *cachePath = [NSSearchPathForDirectoriesInDomains(NSCachesDirectory, NSUserDomainMask, YES) lastObject]; 16 NSURL *cachePathURL = [NSURL fileURLWithPath:cachePath]; 17 NSString *fileNameByMD5 = [[[response URL] absoluteString] MD5]; 18 NSURL *fileURL = [cachePathURL URLByAppendingPathComponent: fileNameByMD5]; 19 20 NSFileManager *mgr = [NSFileManager defaultManager]; 21 [mgr moveItemAtURL:location toURL:fileURL error:NULL]; 22 23 }]; 24 25 [downloadTask resume];
1 - (NSString *)MD5 2 { 3 const char *cStr = [self UTF8String]; 4 unsigned char digest[CC_MD5_DIGEST_LENGTH]; 5 6 CC_MD5(cStr, strlen(cStr), digest); 7 8 NSMutableString *result = [NSMutableString stringWithCapacity:CC_MD5_DIGEST_LENGTH * 2]; 9 10 for(int i = 0; i < CC_MD5_DIGEST_LENGTH; i++) { 11 [result appendFormat:@"%02x", digest[i]]; 12 } 13 14 return result; 15 }
3.NSURLSessionDownloadTask实现复杂的下载功能:断点续传\后台下载
http://blog.csdn.net/majiakun1/article/details/38133789