有关在文件夹中保存数组

在你的应用里创建directory：

NSArray *paths = NSSearchPathForDirectoriesInDomains(NSLibraryDirectory, NSUserDomainMask, YES); 
NSString *documentsDirectory = [paths objectAtIndex:0];
NSString *folderPath = [documentsDirectory stringByAppendingPathComponent:@"UniqueUserAccount"];

if (![[NSFileManager defaultManager] fileExistsAtPath:folderPath])
   [[NSFileManager defaultManager] createDirectoryAtPath:folderPath withIntermediateDirectories:NO attributes:nil error:&error]; 

保存NSMutableArray，如果不明白可以百度相关说明

folderPath = [folderPath stringByAppendingPathComponent:@"array.out"]; 
[yourArray writeToFile:folderPath atomically:YES];

读取数组：

NSArray *arrayFromFile = [NSArray arrayWithContentsOfFile:folderPath];
NSLog(@"%@",arrayFromFile);

如果要保存图片的话：

for(int i = 0;i < [arrImages count];i++)
{
  folderPath = [folderPath stringByAppendingPathComponent:[NSString stringWithFormat:@"Images%d",i]];
  NSMutableString *imgPath;
  imgPath=[[NSMutableString  alloc] initWithString: [[NSBundle mainBundle] resourcePath]]; 
 [imgPath stringByAppendingPathComponent:[arrImages objectAtIndex:i]];
 NSData *imageData = [NSData dataWithContentsOfFile:imgPath]; 

 NSData *imageData = UIImagePNGRepresentation([arrImages objectAtIndex:i]) 

 [imageData writeToFile:folderPath atomically:YES]; 
}