小编use*_*228的帖子

我想获得UIImage Object真正的内存大小.有3种方法

NSUInteger s1 = UIImagePNGRepresentation(thumbImage).length;
NSUInteger s2 = UIImageJPEGRepresentation(thumbImage, 1).length;
NSUInteger s3  = CGImageGetHeight(thumbImage.CGImage) * CGImageGetBytesPerRow(thumbImage.CGImage);
NSLog(@"s1:%u",s1);
NSLog(@"s2:%u",s2);
NSLog(@"s3:%u",s3);

和结果

S1:62734

S2:175939

S3:578816

哪一个是对的？