将Array、Dictionary等集合类的序列化和反序列化

Objective-C的集合类序列化到文件中或者从文件中反序列化其实很简单，请看下面的示例代码：

NSArray *array = [NSArray arrayWithObjects:
@"Hefeweizen", @"IPA", @"Pilsner", @"Stout", nil];
NSDictionary *dictionary = [NSDictionary dictionaryWithObjectsAndKeys:
array, @"array", @"Stout", @"dark", @"Hefeweizen", @"wheat", @"IPA",
@"hoppy", nil];
// 得到documents directory的路径
NSArray *paths = NSSearchPathForDirectoriesInDomains(NSDocumentDirectory,
NSUserDomainMask, YES);
if ([paths count] > 0)
{
// Array的保存路径
NSString *arrayPath = [[paths objectAtIndex:0]
stringByAppendingPathComponent:@"array.out"];
// dictionary的保存路径
NSString *dictPath = [[paths objectAtIndex:0]
stringByAppendingPathComponent:@"dict.out"];
// 保存array
[array writeToFile:arrayPath atomically:YES];
// 保存dictionary
[dictionary writeToFile:dictPath atomically:YES];
// 从文件中读取回来
NSArray *arrayFromFile = [NSArray arrayWithContentsOfFile:arrayPath];
NSDictionary *dictFromFile = [NSDictionary dictionaryWithContentsOfFile:dictPath];
for (NSString *element in arrayFromFile)
NSLog(@"Beer: %@", element);
for (NSString *key in dictFromFile)
NSLog(@"%@ Style: %@", key, [dictionary valueForKey:key]);
}