根据二进制流转成图片 几种方式

1： 

   NSData *imageData = [[NSData alloc] initWithBase64EncodedString:dict1[@"msg"] options:NSDataBase64DecodingIgnoreUnknownCharacters];

        _fenxiangtupianimageview = [UIImage imageWithData:imageData];

2：       

  NSData * yanzhengmadata = [NSData dataWithContentsOfURL:[NSURL URLWithString:pinjieyanzhengmatupianlianjie]];

  self.yanzhengmatupianimage.image = [[UIImage alloc]initWithData:yanzhengmadata];