NSString* url = @"http://www.sinaimg.cn/dy/slidenews/1_img/2014_21/2841_421528_847373.jpg";
NSData* data = [NSData dataWithContentsOfURL:[NSURL URLWithString:url]];
UIImage* jpg = [UIImage imageWithData:data];
NSString* url = @"http://www.sinaimg.cn/dy/slidenews/1_img/2014_21/2841_421528_847373.jpg";
NSData* data = [NSData dataWithContentsOfURL:[NSURL URLWithString:url]];
UIImage* jpg = [UIImage imageWithData:data];