将 NSMutableArray 保存到 NSUserDefaults 的最佳方法是什么？

我有一个名为 Occasion 的自定义对象，定义如下：

#import <Foundation/Foundation.h>


@interface Occasion : NSObject {

NSString *_title;
NSDate *_date;
NSString *_imagePath;    

}

@property (nonatomic, retain) NSString *title;
@property (nonatomic, retain) NSDate *date;
@property (nonatomic, retain) NSString *imagePath;

现在我有一个 NSMutableArray of Occasions，我想将其保存到 NSUserDefaults 中。我知道这是不可能的，所以我想知道哪种方法最简单？如果序列化是答案，那么如何实现呢？因为我阅读了文档但无法完全理解它的工作方式。

你应该使用类似的东西NSKeyedArchiver将数组序列化为NSData，将其保存到NSUserDefaults然后使用NSKeyedUnarchiver稍后反序列化它：

NSData *serialized = [NSKeyedArchiver archivedDataWithRootObject:myArray];
[[NSUserDefaults standardUserDefaults] setObject:serialized forKey:@"myKey"];

//...

NSData *serialized = [[NSUserDefaults standardUserDefaults] objectForKey:@"myKey"];
NSArray *myArray = [NSKeyedUnarchiver unarchiveObjectWithData:serialized];

您将需要实施NSCoding协议在你的Occasion类并正确保存各种属性以使其正常工作。欲了解更多信息，请参阅档案和序列化编程指南 http://developer.apple.com/library/ios/#DOCUMENTATION/Cocoa/Conceptual/Archiving/Archiving.html。执行此操作不应超过几行代码。就像是：

- (void)encodeWithCoder:(NSCoder *)coder {
    [super encodeWithCoder:coder];

    [coder encodeObject:_title forKey:@"_title"];
    [coder encodeObject:_date forKey:@"_date"];
    [coder encodeObject:_imagePath forKey:@"_imagePath"];
}

- (id)initWithCoder:(NSCoder *)coder {
    self = [super initWithCoder:coder];

    _title = [[coder decodeObjectForKey:@"_title"] retain];
    _date = [[coder decodeObjectForKey:@"_date"] retain];
    _imagePath = [[coder decodeObjectForKey:@"_imagePath"] retain];

    return self;
}