IOS数据持久化之归档NSKeyedArchiver, NSUserDefaults,writeToFile

 
    //2.文件读写
    //支持:NSString, NSArray , NSDictionay, NSData
     //注:集合(NSArray, NSDictionay)中得元素也必须是这四种类型, 才能够进行文件读写
     
     //string文件读写
    NSString *string = @"假如给我有索纳塔";
   
    //Document
    NSString *docPath = [NSSearchPathForDirectoriesInDomains(NSDocumentDirectory, NSUserDomainMask, YES) firstObject];
    //指定文件路径 aaa.txt
    NSString *filePath = [docPath stringByAppendingPathComponent:@"aaa.txt"];
    NSLog(@"**%@", filePath);
    //写入文件
    //参数1:文件路径, 如果文件路径下没有此文件, 系统会自动创建一个文件.
    //参数2:是否使用辅助文件
    //参数3:编码格式
    //参数4:错误
    NSError *error = nil;
    BOOL result = [string writeToFile:filePath atomically:YES encoding:NSUTF8StringEncoding error:&error];
    if (result) {
        NSLog(@"写入成功");
    } else {
    
        NSLog(@"写入错误");
    }
    if (error) {
        NSLog(@"出现错误");
    }
    
    //取值操作,
    NSError  *error1 = nil;
    NSString *contenSring = [[NSString alloc] initWithContentsOfFile:filePath encoding:NSUTF8StringEncoding error:&error1];
    if (error1) {
        NSLog(@"error:%@", error1);
    } else {
        NSLog(@"文件内容%@", contenSring);
    }
    [contenSring release];
    
    
    
    
    //NSArray的文件读写
    
    NSArray *array = @[@"123", @"abc", @"apm"];
    //写入操作, 格式XML
    //Library, test.txt
    //library路径
    NSString *libraryPath1 = [NSSearchPathForDirectoriesInDomains(NSLibraryDirectory, NSUserDomainMask, YES) firstObject];
    //文件路径
    NSString *textPath = [libraryPath1 stringByAppendingPathComponent:@"text.txt"];
    NSLog(@"%@", textPath);
    //写入
    BOOL result4 = [array writeToFile:textPath atomically:YES];
    //判断是否写入成功
    if (result4) {
        NSLog(@"写入成功");
    } else {
        NSLog(@"写入失败");
    }
    
    //取值操作
   
    NSArray *bbb = [[NSArray alloc] initWithContentsOfFile:textPath];
    NSLog(@"%@", bbb);
    [bbb release];
    
    
    
    
    
    //NSDictionary, 格式:XMl
    NSDictionary *dic = @{@"a": @"aaa", @"1": @"111", @"*" :@"**"};
    //Caches, dic.txt
    //Caches文件路径
    NSString *cachesPath1 = [NSSearchPathForDirectoriesInDomains(NSCachesDirectory, NSUserDomainMask, YES)firstObject];
    //dic.txt路径
    NSString *dicPath = [cachesPath1 stringByAppendingPathComponent:@"dic.txt"];
    NSLog(@"%@", dicPath);
    //写入
    BOOL result3 = [dic writeToFile:dicPath atomically:YES];
    //判断写入是否成功
    if (result3) {
        NSLog(@"写入成功");
    } else {
        NSLog(@"写入shib");
    }
    //取值操作
    NSDictionary *dict = [[NSDictionary alloc] initWithContentsOfFile:dicPath];
    NSLog(@"%@", dict);
    [dict release];
    
    
    
    //NSData NSString *tmpPath = NSTemporaryDirectory();
    NSString *string2 = @"132456789";
    //字符串转data
     NSData *data = [string2 dataUsingEncoding:NSUTF8StringEncoding];
    //tmp路径
    //tmp data.txt
    NSString *tmpPath1 = NSTemporaryDirectory();
    //data.txt路径
     NSString *dataPath = [tmpPath1 stringByAppendingPathComponent:@"data.txt"];
    //写入
    BOOL result1 = [data writeToFile:dataPath atomically:YES];
    //判断是否写入成功
    if (result1) {
        NSLog(@"写入成功");
    } else {
        NSLog(@"写入失败");
    }
    
    //取值
    NSData *datat = [[NSData alloc] initWithContentsOfFile:dataPath];
    NSString *dataSting = [[NSString alloc] initWithData:datat encoding:NSUTF8StringEncoding];
     [datat release];
    NSLog(@"%@", dataSting);
    [dataSting release];
    

    //3.归档 / 反归档
    //归档的实质:把其他类型数据(比如:Person),先转化成NSData, 再写入文件
    //能进行归档的对象, 必须遵守<NSCoding>
    
    //归档
    Person *person = [[[Person alloc] init] autorelease];
    person.name = @"辉哥";
    person.age = @"18";
    person.gender = @"男";
    //NSLog(@"%@", person);
    
    
    //可变data
    NSMutableData *mData = [[NSMutableData alloc] initWithCapacity:0];
    
    //NSKeyedArchiver, 压缩工具, 继承于NSCoder,主要用于编码
    NSKeyedArchiver *archiver= [[NSKeyedArchiver alloc] initForWritingWithMutableData:mData];
    //把Person对象压到Data中
    [archiver encodeObject:person forKey:@"girlFriend"];
    //完成压缩
    [archiver finishEncoding];
    [archiver release];
    NSLog(@"%@", mData);
    
    //主目录中, person.txt
      NSString *homePatha = NSHomeDirectory();
      NSString *mDataPath = [homePatha stringByAppendingPathComponent:@"person.txt"];
    NSLog(@"%@", mDataPath);
    BOOL result = [mData writeToFile:mDataPath atomically:YES];
    if (result) {
        NSLog(@"写入成功");
    } else {
        NSLog(@"写入失败");
    }
    [mData release];

    //反归档
    NSData *contentData = [[NSData alloc] initWithContentsOfFile:mDataPath];
    //NSKeyedUnarchiver解压工具, 继承于NSCoder
    NSKeyedUnarchiver *unarchiver = [[NSKeyedUnarchiver alloc] initForReadingWithData:contentData];
    [contentData release];
    //通过key找到person
   Person *contentPerson = [unarchiver decodeObjectForKey:@"girlFriend"];
    NSLog(@"gd%@", contentPerson);
    [unarchiver release];
    

  
    //数据持久化:数据永久的保存
    //数据持久化的实质:把数据写入文件, 再把文件存到硬盘
    //IOS沙盒机制:IOS系统为每个app生成一个文件夹(沙盒), 这个文件夹只允许当前的APP访问
    //沙盒的主目录
    //沙盒主目录的文件夹名字由 十六进制数 和 - 组成, 保证沙盒安全性
    //NSHomeDirectory()
    NSString *homePath = NSHomeDirectory();
    NSLog(@"%@", homePath);
    
    //Documents文件
    //存放着一些比较重要的用户信息, 比如游戏的存档
    //Documents中得文件会被备份 或者 存入iCloud 中, 所以存到documents中得文件不能过大, 如果过大, 会在应用审核过程中遭到拒审
    //参数1:文件夹名称
    //参数2:搜素域 优先级user>local>network>system
    //参数3:相对路径或者绝对路径, yes 是绝对, no是相对
    //因为相同文件名的文件可能有多个, 所以返回的是一个数组
    NSArray *paths = NSSearchPathForDirectoriesInDomains(NSDocumentDirectory, NSUserDomainMask, YES);
    //NSLog(@"%@", paths);
    
    NSString *docmentsPath = [paths firstObject];
    //NSLog(@"%@", docmentsPath);
    
    //Library,资源库 存放一些不太重要, 相对比较大得文件
    NSString *libraryPath = [NSSearchPathForDirectoriesInDomains(NSLibraryDirectory, NSUserDomainMask, YES) firstObject];
    //NSLog(@"libraryPath:%@", libraryPath);
    //Library/Caches, 缓存, 网页缓存, 图片缓存, 应用中得"清理缓存"功能, 就是清理这个文件夹下得内容
    NSString *cachesPath = [NSSearchPathForDirectoriesInDomains(NSCachesDirectory, NSUserDomainMask, YES) firstObject];
    //NSLog(@"%@", cachesPath);
    //LanunchImages, 由LaunchScreen.xib生成的启动图片
    
    
    //Library/Preferences, 偏好设置, 存放用户对这个应用的设置或配置
    //注:路径找不到,通过NSUserDefaults访问
    
    
    //tmp, 临时文件, 存放下载的压缩包, 解压过后删除
    NSString *tmpPath = NSTemporaryDirectory();
    NSLog(@"%@", tmpPath);
    
    //  *.app, 包,用右键,显示包内容, 查看里面存放的文件
    //IOS8.0以后, *.app单独存放到一个文件内
    //  *.app中这个文件,只能够访问,不能够修改(写入)
    NSString *bundlePath = [[NSBundle mainBundle] bundlePath];
    NSLog(@"***%@", bundlePath);
    
    
    //NSFileManager文件管理工具, 主要用于添加, 移动, 修改, 拷贝文件, 继承于NSObject
    //文件管理工具是个单例
    NSFileManager *fm = [NSFileManager defaultManager];
    //文件路径
    NSString *hPath = [[fm URLsForDirectory:NSDocumentDirectory inDomains:NSUserDomainMask] firstObject];
    NSLog(@"hPath:%@", hPath);
    
    //创建文件夹,
    //在主目录中创建images文件夹
    NSString *mainPath = NSHomeDirectory();
    NSString *directoryPath = [mainPath stringByAppendingPathComponent:@"images"];
    NSLog(@"%@", directoryPath);
    
    NSError *error = nil;
    //attributes设置文件夹的属性,读写,隐藏等等
    //NSDictionary *attributes = @{NSFileAppendOnly: @YES};
    BOOL result = [fm createDirectoryAtPath:directoryPath withIntermediateDirectories:YES attributes:nil error:&error];
    if (result) {
        NSLog(@"创建成功");
    } else {
    
        NSLog(@"创建失败");
    }
    
    //创建文件
    //在Images文件夹中创建image.png
    NSString *imagePath = [directoryPath stringByAppendingPathComponent:@"image.png"];
    NSLog(@"%@", imagePath);
    
    //找图片
    NSString *meinvPath = [[NSBundle mainBundle] pathForResource:@"美女7" ofType:@"png"];
    NSData *imageData = [NSData dataWithContentsOfFile:meinvPath];
    
    //创建图片
    BOOL result2 = [fm createFileAtPath:imagePath contents:imageData attributes:nil];
    if (result2) {
        NSLog(@"创建成功");
    } else {
        NSLog(@"创建失败");
    }
    
    //判断文件是否存在
    if ([fm fileExistsAtPath:imagePath]) {
        NSLog(@"存在");
        //删除
        NSError *error = nil;
       BOOL result = [fm removeItemAtPath:imagePath error:&error];
        if (result) {
            NSLog(@"删除成功");
        } else {
            NSLog(@"删除失败%@", error);
        }
    }
    
    NSString *path = NSHomeDirectory();
    NSString *filePath = [path stringByAppendingPathComponent:@"aaa.txt"];
    NSLog(@"1*%@", filePath);
    NSString *filePath1 =[path stringByAppendingString:@".aaa.txt"];
    NSLog(@"2*%@", filePath1);
    NSString *filePath2 = [path stringByAppendingFormat:@"/baa.txt"];
    NSLog(@"3*%@", filePath2);
    NSString *filePath3 = [path stringByAppendingPathExtension:@"caaa.txt"];
    NSLog(@"4*%@", filePath3);
    
    
    
    
    

    //数据持久化的方式
   //1. NSUserDefaults, 继承于NSObject, 单例设计模式, 内部存值用的KVC
    NSInteger money = 100000;
    money -= 99999;
    
    //存数据, 存放到PreFerences文件夹内的*.plist文件中, 以字典的形式存储
    NSUserDefaults *userDefaults = [NSUserDefaults standardUserDefaults];
    
    [userDefaults setInteger:1 forKey:@"myMoney"];
    //同步操作, 让存入的数据写入文件
    [userDefaults synchronize];
    
    
    //取数据, key和存数据的key保持一致
    NSUserDefaults *user = [NSUserDefaults standardUserDefaults];
    NSInteger myMoney = [user integerForKey:@"myMoney"];
    NSLog(@"%ld", myMoney);
    
    
    NSUserDefaults *defaults = [NSUserDefaults standardUserDefaults];
    NSInteger mmoney = [defaults integerForKey:@"myLifeMoney"];
    if (mmoney <= 10) {
        NSLog(@"不能花了");
    } else {
        NSLog(@"花了10, 吃了俩");
        mmoney -= 10;
        [defaults setInteger:mmoney forKey:@"myLifeMoney"];
        [defaults synchronize];
    }
 
    
    //NSUserDefaults, 支持的数据类型:array, dictionary, string, data, date, number, bool
    //NSUserDefaults, 一般存一些数值, 不存大量的数据
    //是不是第一次启动
    NSUserDefaults *userDefault1 = [NSUserDefaults standardUserDefaults];
    BOOL isFirst = [userDefault1 boolForKey:@"isFirst"];
    if (isFirst == NO) {
        NSLog(@"第一次启动");
        [userDefault1 setBool:YES forKey:@"isFirst"];
    } else {
        NSLog(@"不是第一次启动");
    }

Person.h 中实现NSCoding协议   

#import <Foundation/Foundation.h>

@interface Person : NSObject<NSCoding>

@property (nonatomic , retain) NSString *name, *age, *gender;

@end

Person.m 中实现的方法

#import "Person.h"

@implementation Person
- (void)dealloc
{
    [_age release];
    [_name release];
    [_gender release];
    [super dealloc];
    
}

- (NSString *)description
{
    return [NSString stringWithFormat:@"name:%@, age:%@, gender:%@", _name, _age, _gender];
}

#pragma mark - NSCoding
- (void)encodeWithCoder:(NSCoder *)aCoder {
    //编码
    [aCoder encodeObject:self.name forKey:@"NAME"];
    [aCoder encodeObject:self.age forKey:@"AGE"];
    [aCoder encodeObject:self.gender forKey:@"GENDER"];
}
- (id)initWithCoder:(NSCoder *)aDecoder {
    self = [super init];
    if (self) {
        //解码
        self.name = [aDecoder decodeObjectForKey:@"NAME"];
        self.age = [aDecoder decodeObjectForKey:@"AGE"];
        self.gender = [aDecoder decodeObjectForKey:@"GENDER"];
    }
    return self;
}


@end

@interface Person : NSObject<NSCoding>