ios设备如何获取存储空间，

-(void)usedSpaceAndfreeSpace{
NSString* path = [NSSearchPathForDirectoriesInDomains(NSDocumentDirectory, NSUserDomainMask, YES) objectAtIndex:0] ;
NSFileManager* fileManager = [[NSFileManager alloc ]init];
NSDictionary *fileSysAttributes = [fileManager attributesOfFileSystemForPath:path error:nil];
NSNumber *freeSpace = [fileSysAttributes objectForKey:NSFileSystemFreeSize];
NSNumber *totalSpace = [fileSysAttributes objectForKey:NSFileSystemSize];
spaceLabel.text = [NSString stringWithFormat:@"已占用%0.1fG/剩余%0.1fG",([totalSpace longLongValue] - [freeSpace longLongValue])/1024.0/1024.0/1024.0,[freeSpace longLongValue]/1024.0/1024.0/1024.0];
}