iphone - 为自定义类保存到 nsuserdefaults 的最佳方法？

Question

如果我有一个自定义类 Person，它具有三个变量(已属性化和合成):

NSString* theName;
float* theHeight;
int theAge;

Person 实例存储在 NSArray 'Group' 中。只有一个组。在 NSUserDefaults 中存储和加载组的最佳方式是什么？ (记住 float 和 int 对于 NSUserDefaults 是不合法的)

Answer 1

@Brad Smith 的回答并不完整，甚至在某种意义上是不正确的。我们必须使用 NSKeyedArchiver 和 NSKeyedUnarchiver 如下:

使您的类(例如在本例中为 Person)符合协议(protocol) NSCoding 并将这两种方法实现为:

- (id)initWithCoder:(NSCoder *)decoder {
    self = [super init];
    if(self) {
        self.name = [decoder decodeObjectForKey:<key_for_property_name>];
        // as height is a pointer
        *self.height = [decoder decodeFloatForKey:<key_for_property_height>];
        self.age = [decoder decodeIntForKey:<key_for_property_age>];
    }
    return self;
}

- (void)encodeWithCoder:(NSCoder *)encoder {
    [encoder encodeObject:self.name forKey:<key_for_property_name>];
    //as height is a pointer
    [encoder encodeFloat:*self.height forKey:<key_for_property_height>]
    [encoder encodeInt:self.age forKey:<key_for_property_age>];
}

使用 NSUserDefaults

// Write to NSUserDefaults
NSData *archivedObject = [NSKeyedArchiver archivedDataWithRootObject:<your_class_object>];
NSUserDefaults *defaults = [NSUserDefaults standardUserDefaults];
[defaults setObject:archivedObject forKey:<key_for_archived_object>];
[defaults synchronize];

// Read from NSUserDefaults
NSUserDefaults *defaults = [NSUserDefaults standardUserDefaults];
NSData *archivedObject = [defaults objectForKey:<key_for_archived_object>];
<your_class> *obj = (<your_class> *)[NSKeyedUnarchiver unarchiveObjectWithData:archivedObject];