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 = @[@"", @"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", @"": @"", @"*" :@"**"};
    //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 = @"";
    //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 = @"";
     person.gender = @"男";
     //NSLog(@"%@", person);

     //可变data
     NSMutableData *mData = [[NSMutableData alloc] initWithCapacity:];

     //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 = ;
     money -= ;

     //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: 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 <= ) {
         NSLog(@"不能花了");
     } else {
         NSLog(@"花了10, 吃了俩");
         mmoney -= ;
         [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>