iOS数据持久化（一）

    //获取沙盒主目录
    NSString *path = NSHomeDirectory();
    NSLog(@"%@",path);

//Documents  存放的一些比较重要的文件，但是存入Documents中的文件不能过大
    //如何获取Documents文件目录
    NSString *documentsPath = [NSSearchPathForDirectoriesInDomains(NSDocumentDirectory, NSUserDomainMask, YES) firstObject];
    NSLog(@"%@",documentsPath);
    //用firstobject取值是因为该方法一开始使用mac端OS X开发，对于PC端用户可以有多个用户，所以可以取到很多user的路径，但是该方法现在用于手机开发，手机端只有一个用户，所以获得的用户只有一个，lastobject也是可以的。
    
    //Library:是一个资源库，存储一些不太重要的数据，相对比较大一些，里边有两个子文件夹；
    NSString *libraryPath = [NSSearchPathForDirectoriesInDomains(NSLibraryDirectory, NSUserDomainMask, YES)firstObject];
    //Caches:缓存文件，图片缓存，音频，视频。网页资源。应用程序清除缓存，就是清除该文件夹
    NSString *cachesPath  = [NSSearchPathForDirectoriesInDomains(NSCachesDirectory, NSUserDomainMask, YES)firstObject];
    //Preferences:系统偏好设置，用户对应程序的设置，比如用户名和用户密码，preference路径无法找到，通过NSUserDefaults
    
    //temp:存放临时文件，比如下载的压缩包zip，解压后理解把压缩包删除
    NSString *tempPath = NSTemporaryDirectory();
    NSLog(@"%@",tempPath);
    //bundle:ios8之前，包和沙河在同一个目录下，之后.app单独存储到一个独立的文件目录下。 .app 文件 readOnly。从appStore下载下来的是这个包，程序上传的时候也是这个包
    NSString *bundlepath = [[NSBundle mainBundle] bundlePath];
    NSLog(@"%@",bundlepath);

    // NSSearchPathDirectory 这个类是用来查找文件目录的
    //第一个参数：文件名称
    //第二个参数，确定搜索域
    //第三个参数：确定相对路径还是绝对路径。YES绝对，NO相对

/**
 *  文件删除
 */
- (void)deleteFile {
    NSString *cachesPath = [NSSearchPathForDirectoriesInDomains(NSCachesDirectory, NSUserDomainMask, YES) firstObject];

     NSString *imagePath = [cachesPath stringByAppendingPathComponent:@"iamge"];
    NSLog(@"%@",imagePath);
    //创建文件管理者
    NSFileManager *fileManager =  [NSFileManager defaultManager];
    //判断文件是否存在
    BOOL isExist = [fileManager fileExistsAtPath:imagePath];
    if (!isExist) {
        BOOL isSuccess = [fileManager createDirectoryAtPath:imagePath withIntermediateDirectories:YES attributes:nil error:nil];
        NSLog(@"%@",isSuccess ? @"创建成功" : @"创建失败");
    }
    //删除文件
    if ([fileManager fileExistsAtPath:imagePath]) {
        BOOL isSucess = [fileManager removeItemAtPath:imagePath error:nil];
        NSLog(@"%@",isSucess ? @"删除成功" : @"删除失败");
    }
}

/**
 *  移动
 */
- (void)moveFile {
    NSString *cachesPath = [NSSearchPathForDirectoriesInDomains(NSCachesDirectory, NSUserDomainMask, YES) firstObject];
    
    NSString *imagePath = [cachesPath stringByAppendingPathComponent:@"iamge"];
    NSLog(@"%@",imagePath);
    //创建文件管理者
    NSFileManager *fileManager =  [NSFileManager defaultManager];
    //判断文件是否存在
    BOOL isExist = [fileManager fileExistsAtPath:imagePath];
    if (!isExist) {
        BOOL isSuccess = [fileManager createDirectoryAtPath:imagePath withIntermediateDirectories:YES attributes:nil error:nil];
        NSLog(@"%@",isSuccess ? @"创建成功" : @"创建失败");
    }
    //删除文件
    //    if ([fileManager fileExistsAtPath:imagePath]) {
    //        BOOL isSucess = [fileManager removeItemAtPath:imagePath error:nil];
    //        NSLog(@"%@",isSucess ? @"删除成功" : @"删除失败");
    //    }
    //拷贝文件
    //    把包中的plist文件拷贝到image文件夹下
    NSString *plistInBundlePath = [[NSBundle mainBundle] pathForResource:@"NB.plist" ofType:nil];
    
    NSString *nBPath = [imagePath stringByAppendingPathComponent:@"NB.plist"];
    // 拷贝，
    if (![fileManager fileExistsAtPath:nBPath]) {
        BOOL isSuccess = [fileManager copyItemAtPath:plistInBundlePath toPath:nBPath error:nil];
        NSLog(@"%@",isSuccess ? @"拷贝成功" : @"拷贝失败");
    }
    
    NSString *toPath = [NSSearchPathForDirectoriesInDomains(NSDocumentDirectory, NSUserDomainMask, YES)firstObject];
    BOOL isSuccess = [fileManager moveItemAtPath:nBPath toPath:[toPath stringByAppendingPathComponent:@"NB.plist"] error:nil];
    NSLog(@"%@",isSuccess ? @"移动成功" : @"移动失败");
    
}

//字符串写入文件
- (void)writeToFile {
    //简单对象写入文件：字符串，数组，字典，二进制流 只有这些简单对象支持文件的写入
    //如果要写入的文件数据时数组，字典，必须要保证数组，字典中的数据 也是简单对象（如果是复杂对象，请参照后边的归档，反归档）
    //将字符串写入Documents文件夹下
    NSString *documentsPath = [NSSearchPathForDirectoriesInDomains(NSDocumentDirectory, NSUserDomainMask, YES)firstObject];
    NSString *toPath = [documentsPath stringByAppendingPathComponent:@"string.txt"];
    NSString *string = @"string-string-string-";
    //第一个参数，要写入的文件路径，如果不存在文件，会自动创建    第二个参数，原子性，判断是否需要生成辅助文件，保护在多线程下安全    第三个参数，编码格式    第四个参数，错误信息
    NSError *error = nil;
    BOOL isSuccess = [string writeToFile:toPath atomically:YES encoding:NSUTF8StringEncoding error:&error];
    NSLog(@"%@",isSuccess ? @"写入成功" : @"写入失败");
    
    NSString *str = [NSString stringWithContentsOfFile:toPath encoding:NSUTF8StringEncoding error:nil];
    NSLog(@"%@",str);
}

//数组写入文件
- (void)writeArray {
    
    NSString *str = [NSSearchPathForDirectoriesInDomains(NSLibraryDirectory, NSUserDomainMask, YES)firstObject];
    NSString *toPath = [str stringByAppendingPathComponent:@"array.txt"];
    NSArray *array = @[@"123",@"123"];
    BOOL isSuccess = [array writeToFile:toPath atomically:YES];
    NSLog(@"%@",isSuccess ? @"写入成功" : @"写入失败");
    
    NSArray *arr = [NSArray arrayWithContentsOfFile:toPath];
    NSLog(@"%@",arr);

}

//字典写入文件
- (void)writeDic {
    NSDictionary *dic = @{@"key":@"value"};
    NSString *str = [NSSearchPathForDirectoriesInDomains(NSCachesDirectory, NSUserDomainMask, YES)firstObject];
    NSString *toPath = [str stringByAppendingPathComponent:@"dictonry.txt"];
    BOOL isSuccess = [dic writeToFile:toPath atomically:YES];
    NSLog(@"%@",isSuccess ? @"成功" : @"失败");
    NSDictionary *dict = [NSDictionary dictionaryWithContentsOfFile:toPath];
    NSLog(@"%@",dict);
}

//NSData写入文件
- (void)writeData {
    NSString *tempPath = NSTemporaryDirectory();
    NSString *toPath = [tempPath stringByAppendingPathComponent:@"data.txt"];
    NSString *string = @"datadata";
    NSData *data = [string dataUsingEncoding:NSUTF8StringEncoding];
    BOOL isSuccess = [data writeToFile:toPath atomically:YES];
    NSLog(@"%@",isSuccess ? @"成功" : @"失败");
    NSData *getData = [NSData dataWithContentsOfFile:toPath];
    NSString *str = [[NSString alloc] initWithData:getData encoding:NSUTF8StringEncoding];
    NSLog(@"%@",str);
}

//Preference
- (void)writeToPreference {
    // NSUserDefaults 继承自NSObject ,单例     通过kvc模式赋值
    NSLog(@"%@",NSHomeDirectory());
    //创建用户索引对象
    NSUserDefaults *defaults = [NSUserDefaults standardUserDefaults];
    [defaults setInteger:100 forKey:@"money"];
    //立即同步操作      对preference中的文件进行修改后，立即同步
    [defaults synchronize];
    NSInteger money = [defaults integerForKey:@"money"];
    NSLog(@"%ld",money);
    [defaults setInteger:10000 forKey:@"MyMoney"];
    [defaults synchronize];
    
    NSInteger you = [defaults integerForKey:@"you"];
    NSLog(@"%ld",(long)you);
    if (money < 10) {
        NSLog(@"there is no money");
    } else {
        NSLog(@"-100");
        money -= 100;
        [defaults setInteger:40 forKey:@"money"];
        [defaults setInteger:1000 forKey:@"YourMoney"];
    }
    // NSUserDefaults 一般存储一些比较小的数据，大部分用来存数值
    
    //例子：判断用户是否第一次登陆
    NSUserDefaults *userDefault = [NSUserDefaults standardUserDefaults];
    BOOL isFirst = [userDefault boolForKey:@"isFirst"];
    [userDefault setBool:YES forKey:@"isFirst"];
    [userDefault synchronize];
    if (!isFirst) {
        NSLog(@"第一次登陆");
    } else {
        NSLog(@"不是第一次登陆");
    }
}

//
//  Person.h
//  07.24-DataPersistiser
//
//  Created by lanouhn on 14/7/24.
//  Copyright (c) 2014年 LCD. All rights reserved.
//

#import <Foundation/Foundation.h>

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

//
//  Person.m
//  07.24-DataPersistiser
//
//  Created by lanouhn on 14/7/24.
//  Copyright (c) 2014年 LCD. All rights reserved.
//

#import "Person.h"

@implementation Person

//当要归档时，对象会自动触发这个方法
- (void)encodeWithCoder:(NSCoder *)aCoder {
    [aCoder encodeObject:self.name forKey:@"name"];
    [aCoder encodeObject:self.gender forKey:@"gender"];
    [aCoder encodeObject:@(self.age) forKey:@"age"];
}
- (id)initWithCoder:(NSCoder *)aDecoder {
    self = [super init];
    if (self) {
        self.name = [aDecoder decodeObjectForKey:@"name"];
        self.gender = [aDecoder decodeObjectForKey:@"gender"];
        self.age = [[aDecoder decodeObjectForKey:@"age"] integerValue];
    }
    return self;
}
@end

- (void)archiver {
    
    //把复杂文件写入文件，先转化为nsdata对象
    //归档：归档的实质就是把其他类型的数据（person），先转化为NSData,再写入文件。
    Person *person = [[Person alloc] initWithName:@"rose" gender:@"girl" age:25];
    //    NSKeyedArchiver  压缩工具类，继承自NSCoder，主要用于编码
    NSMutableData *data = [NSMutableData data] ;
    NSKeyedArchiver *achiver = [[NSKeyedArchiver alloc] initForWritingWithMutableData:data];
    //使用压缩工具讲Person压到data中
    [achiver encodeObject:person forKey:@"person"];
    //完成压缩，停掉压缩工具
    [achiver finishEncoding];

    
    NSString *homePath = NSHomeDirectory();
    NSString *toPath = [homePath stringByAppendingPathComponent:@"person.txt"];
    BOOL isSuccess = [data writeToFile:toPath atomically:YES];
    NSLog(@"%@",isSuccess ? @"成功" : @"失败");
    
    //复杂对象的读取，反归档
    //    NSKeyedUnarchiver
    NSData *getData = [NSData dataWithContentsOfFile:toPath];
    NSKeyedUnarchiver *unArchiver = [[NSKeyedUnarchiver alloc] initForReadingWithData:getData];
    //解压
    Person *p1 = [unArchiver decodeObjectForKey:@"person"];
    [unArchiver finishDecoding];
}

 //集合NSArray NSDictionary 如果想进行归档和反归档，那么它里边存储的元素也要遵循NSCoding协议
    Person *person1 = [[Person alloc] initWithName:@"jack" gender:@"男" age:20];
    Person *person2 = [[Person alloc] initWithName:@"rose" gender:@"女" age:20];
    NSArray *array = @[person1,person2];

    
    NSMutableData *data = [NSMutableData data];
    
    NSKeyedArchiver *archiver = [[NSKeyedArchiver alloc] initForWritingWithMutableData:data];
    [archiver encodeObject:array forKey:@"array"];
    [archiver finishEncoding];

    
    NSString *tmpPath = NSTemporaryDirectory();
    NSString *toPath = [tmpPath stringByAppendingString:@"array.txt"];
    
    BOOL isSuccess = [data writeToFile:toPath atomically:YES];
    NSLog(@"%@",isSuccess ? @"成功" : @"失败");
    //反归档
    NSKeyedUnarchiver *unArchiver = [[NSKeyedUnarchiver alloc] initForReadingWithData:data];
    NSArray *unArchiverArray = [unArchiver decodeObjectForKey:@"array"];