ios - 在 iPad 中获得 0.2GB 额外可用空间

Question

当我尝试在 iPad 中获取可用空间时，我通过以下代码获得了 0.2 GB 的额外空间。

- (uint64_t)freeDiskspace {
uint64_t totalSpace = 0;
uint64_t totalFreeSpace = 0;

__autoreleasing NSError *error = nil;
NSArray *paths = NSSearchPathForDirectoriesInDomains(NSDocumentDirectory, NSUserDomainMask, YES);
NSDictionary *dictionary = [[NSFileManager defaultManager] attributesOfFileSystemForPath:[paths lastObject] error: &error];

if (dictionary)
{
    NSNumber *fileSystemSizeInBytes = [dictionary objectForKey: NSFileSystemSize];
    NSNumber *freeFileSystemSizeInBytes = [dictionary objectForKey:NSFileSystemFreeSize];
    totalSpace = [fileSystemSizeInBytes unsignedLongLongValue];
    totalFreeSpace = [freeFileSystemSizeInBytes unsignedLongLongValue];
    NSLog(@"Memory Capacity of %llu MiB with %llu MiB Free memory available.", ((totalSpace/1024ll)/1024ll), ((totalFreeSpace/1024ll)/1024ll));
} else {
    NSLog(@"Error Obtaining System Memory Info: Domain = %@, Code = %d", [error domain], [error code]);
}

return totalFreeSpace;