Question

我正在做一个应用程序作为初学者获得一些经验，我正在制作一个简单的应用程序，在表视图中存储分配。所以我有一个表视图作为主视图和一个加号按钮，它提取一个模态视图控制器，允许用户输入有关 - 类名称，作业标题，作业说明，截止日期和开关打开/的信息关闭通知。这些值存储在AssignmentInfo模型中。我需要能够存档（NSCoding）这些值，并在输入新数据时添加它们。以下是一些可能有助于提供更好想法的示例代码：

AssignmentInfo.h -

@property (nonatomic,strong)NSString *className;
@property (nonatomic,strong)NSString *assignmentDescription;
@property (nonatomic,strong)NSString *assignmentTitle;
@property (nonatomic,strong)NSString *dateTimeString;
@property (nonatomic)bool notifcationStatus;

AddEditViewController.m -

{
    IBOutlet UIDatePicker *dateTimePicker;
}

@property (nonatomic, strong) IBOutlet UITextField *className;
@property (nonatomic, strong) IBOutlet UITextField *assignmentTitle;
@property (nonatomic, strong) IBOutlet UITextField *assignmentDescription;
@property (nonatomic, strong) IBOutlet UISwitch *procrastinationNotificationSwitch;
@property (nonatomic,strong)AssignmentInfo *assignmentInfo;

AddEditViewController.m -

- (IBAction)addTheInfo:(id)sender {

    NSDateFormatter *dateFormatter = [[NSDateFormatter alloc]init];
    dateFormatter.timeZone = [NSTimeZone defaultTimeZone];
    dateFormatter.timeStyle = NSDateFormatterShortStyle;
    dateFormatter.dateStyle = NSDateFormatterShortStyle;
    NSString *dateTimeString = [dateFormatter stringFromDate: dateTimePicker.date];
    self.assignmentInfo.className = self.className.text;
    self.assignmentInfo.assignmentTitle = self.assignmentTitle.text;
    self.assignmentInfo.assignmentDescription = self.assignmentDescription.text;
    self.assignmentInfo.dateTimeString = dateTimeString;
    NSLog(@"%@",self.assignmentInfo.className);    

    [self dismissViewControllerAnimated:YES completion:nil];

}

Answer 1

我将链接来自无与伦比的NSHipster的帖子。 http://nshipster.com/nscoding/

NSCoding是一个简单的协议，有两种方法：-initWithCoder：和 encodeWithCoder：。符合NSCoding的类可以序列化并反序列化为可以存档到磁盘或数据的数据分布在网络上。

@interface Book : NSObject <NSCoding>
@property NSString *title;
@property NSString *author;
@property NSUInteger pageCount;
@property NSSet *categories;
@property (getter = isAvailable) BOOL available;
@end

@implementation Book

#pragma mark - NSCoding

- (id)initWithCoder:(NSCoder *)decoder {
    self = [super init];
    if (!self) {
        return nil;
    }

    self.title = [decoder decodeObjectForKey:@"title"];
    self.author = [decoder decodeObjectForKey:@"author"];
    self.pageCount = [decoder decodeIntegerForKey:@"pageCount"];
    self.categories = [decoder decodeObjectForKey:@"categories"];
    self.available = [decoder decodeBoolForKey:@"available"];

    return self;
}

- (void)encodeWithCoder:(NSCoder *)encoder {
    [encoder encodeObject:self.title forKey:@"title"];
    [encoder encodeObject:self.author forKey:@"author"];
    [encoder encodeInteger:self.pageCount forKey:@"pageCount"];
    [encoder encodeObject:self.categories forKey:@"categories"];
    [encoder encodeBool:[self isAvailable] forKey:@"available"];
}

@end

设置好类后，您可以轻松地从磁盘保存/恢复：

// Archive
[NSKeyedArchiver archiveRootObject:books toFile:@"/path/to/archive"];

// Unarchive
[NSKeyedUnarchiver unarchiveObjectWithFile:@"/path/to/archive"];

所以在你的情况下你有一个这样的课：

@property (nonatomic, strong) NSString *className;
@property (nonatomic, strong) NSString *assignmentDescription;
@property (nonatomic, strong) NSString *assignmentTitle;
@property (nonatomic, strong) NSString *dateTimeString;
@property (nonatomic, assign) BOOL notifcationStatus;

所以你最终得到了一个initWithCoder方法，如：

#pragma mark - NSCoding

- (id)initWithCoder:(NSCoder *)decoder {
    self = [super init];
    if (!self) {
        return nil;
    }

    self.className = [decoder decodeObjectForKey:@"className"];
    self.assignmentDescription = [decoder decodeObjectForKey:@"assignmentDescription"];
    self.assignmentTitle = [decoder decodeIntegerForKey:@"assignmentTitle"];
    self.dateTimeString = [decoder decodeObjectForKey:@"dateTimeString"];
    self.notifcationStatus = [decoder decodeBoolForKey:@"notifcationStatus"];

    return self;
}

和encodeWithCoder类似：

- (void)encodeWithCoder:(NSCoder *)encoder {
    [encoder encodeObject:self.className forKey:@"className"];
    [encoder encodeObject:self.assignmentDescription forKey:@"assignmentDescription"];
    [encoder encodeInteger:self.assignmentTitle forKey:@"assignmentTitle"];
    [encoder encodeObject:self.dateTimeString forKey:@"dateTimeString"];
    [encoder encodeBool:self.notifcationStatus forKey:@"notifcationStatus"];
}

现在您应该能够将新创建的对象添加到NSMutableArray中，并在必要时将该阵列保存到磁盘/从磁盘加载。

我需要一些帮助归档NSArray以保存一些值并在以后添加/删除它们

1 个答案: