NSData转化为图片   

NSString *string = @"http://img0.bdstatic.com/img/image/shouye/mxfbb-9427886853.jpg";

NSURL *url = [NSURL URLWithString:[string stringByAddingPercentEscapesUsingEncoding:NSUTF8StringEncoding]];

NSData *data = [NSData dataWithContentsOfURL:url];

UIImage *Image1 = [UIImage imageWithData:data];