//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");

     }

#import <Foundation/Foundation.h>

@interface Person : NSObject<NSCoding>

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

@end

 #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