自定义对象数据持久化

//
//  Person.h
//  自定义对象数据持久化
//
//  Created by shimei on 7/29/16.
//  Copyright © 2016 Shimei. All rights reserved.
//

#import <Foundation/Foundation.h>

@interface Person : NSObject <NSCoding>
@property (assign, nonatomic) NSInteger  pid;
@property (copy,   nonatomic) NSString  *name;
@property (assign, nonatomic) NSInteger  age;
@property (copy,   nonatomic) NSString  *gender;

- (instancetype)initWithPid:(NSInteger)pid
                      name:(NSString *)name
                        age:(NSInteger)age
                     gender:(NSString *)gender;

- (instancetype)initWithDictionary:(NSDictionary *)dict;

@end

//
//  Person.m
//  自定义对象数据持久化
//
//  Created by shimei on 7/29/16.
//  Copyright © 2016 Shimei. All rights reserved.
//

#import "Person.h"

@implementation Person
- (instancetype)initWithPid:(NSInteger)pid name:(NSString *)name age:(NSInteger)age gender:(NSString *)gender {
    if (self = [super init]) {
        _pid = pid;
        _name = name;
        _age = age;
        _gender = gender;
    }
    return self;
}

- (instancetype)initWithDictionary:(NSDictionary *)dict {
    if (self = [super init]) {
        [self setValuesForKeysWithDictionary:dict];
    }
    return self;
}

#pragma mark - NSCoding 编码和解码（归档和反归档，压缩和解压缩）
// 归档 编码
- (void)encodeWithCoder:(NSCoder *)aCoder {
    [aCoder encodeInteger:_pid forKey:@"pid"];
    [aCoder encodeObject:_name forKey:@"name"];
    [aCoder encodeInteger:_age forKey:@"age"];
    [aCoder encodeObject:_gender forKey:@"gender"];
}

// 反归档 解码
- (instancetype)initWithCoder:(NSCoder *)aDecoder {
    if (self = [super init]) {
        _pid = [aDecoder decodeIntegerForKey:@"pid"];
        _name = [aDecoder decodeObjectForKey:@"name"];
        _age = [aDecoder decodeIntegerForKey:@"age"];
        _gender = [aDecoder decodeObjectForKey:@"gender"];
    }
    return self;
}
@end

//
//  ViewController.h
//  自定义对象数据持久化
//
//  Created by shimei on 7/29/16.
//  Copyright © 2016 Shimei. All rights reserved.
//

#import <UIKit/UIKit.h>

@interface ViewController : UIViewController

@end

//
//  ViewController.m
//  自定义对象数据持久化
//
//  Created by shimei on 7/29/16.
//  Copyright © 2016 Shimei. All rights reserved.
//

#import "ViewController.h"
#import "Person.h"

@interface ViewController ()
@property (copy,   nonatomic) NSString *filePath;
@end

@implementation ViewController
- (NSString *)filePath {
    if (!_filePath) {
        NSString *docPath = NSSearchPathForDirectoriesInDomains(NSDocumentDirectory, NSUserDomainMask, YES).firstObject;
        _filePath = [docPath stringByAppendingPathComponent:@"person.plist"];
    }
    return _filePath;
}

- (void)viewDidLoad {
    [super viewDidLoad];
    NSLog(@"file path:%@",self.filePath);
    
    NSFileManager *fileManager = [NSFileManager defaultManager];
    if ([fileManager fileExistsAtPath:self.filePath]) { // 文件已经存在，进行读取文件（反归档）
        NSLog(@"反归档");
        NSData *data = [NSData dataWithContentsOfFile:self.filePath];
        NSKeyedUnarchiver *unarchiver = [[NSKeyedUnarchiver alloc] initForReadingWithData:data];
        Person *aPerson = [unarchiver decodeObjectForKey:@"person"];
        [unarchiver finishDecoding];
        
        NSLog(@"pid:%ld, name:%@, age:%ld, gender:%@",aPerson.pid, aPerson.name, aPerson.age, aPerson.gender);
        
    } else { // 文件不存在，进行写入文件（归档）
        NSLog(@"归档");
        // 创建并实例化一个Person对象
        Person *person = [[Person alloc] initWithPid:1001 name:@"LSM" age:18 gender:@"m"];
        NSMutableData *mdata = [NSMutableData data];
        NSKeyedArchiver *archiver = [[NSKeyedArchiver alloc] initForWritingWithMutableData:mdata];
        [archiver encodeObject:person forKey:@"person"];
        [archiver finishEncoding];
        
        // 把数据写入到disk
        [mdata writeToFile:self.filePath atomically:YES];
    }
}

- (void)didReceiveMemoryWarning {
    [super didReceiveMemoryWarning];
    // Dispose of any resources that can be recreated.
}

@end