UIday1801:沙盒三个文件的路径的获取、简单与复杂对象的读写、NSUserDefaults、NSFileManager

初级数据持久化(沙盒三个文件的路径的获取、简单与复杂对象的读写、NSUserDefaults、NSFileManager  )

NSDocumentDirectory 是指程序中对应的Documents路径，而NSDocumentionDirectory对应于程序中的Library/Documentation路径，这个路径是没有读写权限的，所以看不到文件生成。

IOS开发是在沙盒中开发的，对一些部分的文件的读写进行了限制，只能在几个目录下读写文件：
 （1）Documents：应用中用户数据可以放在这里，iTunes备份和恢复的时候会包括此目录
 （2）tmp：存放临时文件，iTunes不会备份和恢复此目录，此目录下文件可能会在应用退出后删除
 （3）Library/Caches：存放缓存文件，iTunes不会备份此目录，此目录下文件不会在应用退出删除
 对于文件操作，NSSearchPathForDirectoriesInDomains是核心函数。

ViewController.m

#import "ViewController.h"#import "Person.h"@interface ViewController ()@property(nonatomic,strong)UIImageView * imV;@end@implementation ViewController- (void)viewDidLoad {    [super viewDidLoad];    // Do any additional setup after loading the view, typically from a nib.        // 沙盒 就是一个文件夹    // *********获取沙盒路径************/*    // 获取用户名    NSString * s = NSUserName();        // 获取主路径    NSString * rootPath = NSHomeDirectoryForUser(s);        NSLog(@"%@",rootPath);   */        // ************获取沙盒三个文件夹的路径***********    /*    // other    NSString * rootPath1 = NSHomeDirectory();    NSLog(@"rootPath1 = %@",rootPath1);        // 获取doucments路径    // 作用 数据运行程序后产生，主要存储数据库等不常改变的数据文件。存在这里的文件会被备份。（下载的文件不能放在这里，如果放在这上传APPStore的时候会被拒掉）    NSString * documentsPath = NSSearchPathForDirectoriesInDomains(NSDocumentDirectory, NSUserDomainMask, YES)[0];    NSLog(@"documentsPath = %@",documentsPath);        // 获取Caches路径    // 作用存放缓存文件，例如：音频、视频、图片（不会被自动备份）    NSString * cachesPath = NSSearchPathForDirectoriesInDomains(NSCachesDirectory, NSUserDomainMask, YES)[0];    NSLog(@"cachesPath = %@",cachesPath);        // 获取tmp路径    // 作用：存放临时文件，程序下次启动不需要，退出清空。    NSString * tmpPath = NSTemporaryDirectory();    NSLog(@"tmpPath = %@",tmpPath);      */        //***********简单文件的写入*****************/*    //准备路径    NSString * documentsPath = NSSearchPathForDirectoriesInDomains(NSDocumentDirectory, NSUserDomainMask, YES)[0];    NSLog(@"%@",documentsPath);        //----------------NSString的写和读---------------    //NSString  NSArray  NSDictionary  NSData    NSString * str1 = @"hello world";        NSString * filePath = [documentsPath stringByAppendingString:@"/hello.txt"];        //写入//    [str1 writeToFile:filePath atomically:YES encoding:NSUTF8StringEncoding error:nil];        //读出    NSString *s1 = [NSString stringWithContentsOfFile:filePath encoding:NSUTF8StringEncoding error:nil];    NSLog(@"s1 = %@" ,s1);        //------------- NSArray 的写和读 --------------    //stringByAppendingPathComponent: 路径不需要写斜线，不需要写后缀    NSString * filePath2 = [documentsPath stringByAppendingPathComponent:@"array"];    NSArray *array1 = @[@"1",@"2",@"3"];        //写入//    [array1 writeToFile:filePath2 atomically:YES];        //读    NSArray * array2 = [NSArray arrayWithContentsOfFile:filePath2];    //    NSLog(@"array2 = %@",array2);        //------------- NSDictionary 的写和读------------    NSString * filePath3 = [documentsPath stringByAppendingPathComponent:@"Dictionary"];        //写入    NSDictionary * dict = @{@"山西":@"太原",@"河北":@"石家庄"};    [dict writeToFile:filePath3 atomically:YES];        //读    NSDictionary * dict2 = [NSDictionary dictionaryWithContentsOfFile:filePath3];    NSLog(@"dict2  %@",dict2);        //遍历字典    for (id obj in dict2) {        NSLog(@"dict2 %@ = %@",obj,[dict2 valueForKey:obj]);    } */        //*************** 复杂对象写入1 *****************/*    //创建对象    Person * p1 = [[Person alloc]init];    p1.name = @"贝爷";    p1.age = 20;        //准备NSMutableData 存数据    NSMutableData * data = [NSMutableData data];        创建归档工具    NSKeyedArchiver * archiver = [[NSKeyedArchiver alloc]initForWritingWithMutableData:data];        //开始归档    [archiver encodeObject:p1 forKey:@"p1"];        //完成归档    [archiver finishEncoding];        //准备路径    NSString * documentsPath = NSSearchPathForDirectoriesInDomains(NSDocumentDirectory, NSUserDomainMask, YES)[0];    NSString * filePath4 = [documentsPath stringByAppendingPathComponent:@"贝爷.m"];    NSLog(@"%@",documentsPath);        //data写入//    [data writeToFile:filePath4 atomically:YES];        //读    NSData * data1 = [NSData dataWithContentsOfFile:filePath4];    NSLog(@"data1 = %@",data1);        //反归档    NSKeyedUnarchiver * unarchiver = [[NSKeyedUnarchiver alloc]initForReadingWithData:data1];        //转换成对象    Person * p2 = [unarchiver decodeObjectForKey:@"p1"];        //反归档完成    [unarchiver finishDecoding];        NSLog(@"%@ == %ld",p2.name,p2.age);  */        //*************** 复杂对象写入2 *****************/*    //准备路径    NSString * documentsPath = NSSearchPathForDirectoriesInDomains(NSDocumentDirectory, NSUserDomainMask, YES)[0];    //拼接路径    NSString * filePath5 = [documentsPath stringByAppendingPathComponent:@"person.mp4"];        //创建person对象    Person *p3 = [[Person alloc]init];    p3.name = @"六娃";    p3.age = 18;        //存//    [NSKeyedArchiver archiveRootObject:p3 toFile:filePath5];        //取 (这种归档方式，只能针对一个对象)    Person * p4 = [NSKeyedUnarchiver unarchiveObjectWithFile:filePath5];    NSLog(@"%@ == %ld",p4.name,p4.age);  */        //************* NSUserDefaults 通常用来写引导页 ********/*    // 创建对象    NSUserDefaults * ud = [NSUserDefaults standardUserDefaults];        // 存    [ud setObject:@"yan3" forKey:@"lanou"];    // 同步数据    [ud synchronize];        // 取    NSLog(@"%@",[ud objectForKey:@"lanou"]); */        //************** 导航页测试 ****************/*    // 创建对象    // NSUserDefaults 存一些简单的数据    NSUserDefaults * ud = [NSUserDefaults standardUserDefaults];        NSString *s = [ud objectForKey:@"first"];        if (s == nil) {        self.imV = [[UIImageView alloc]initWithImage:[UIImage imageNamed:@"000.png"]];        self.imV.frame = self.view.bounds;        [self.view addSubview:_imV];                [ud setObject:@"NO" forKey:@"first"];    }  */        //*********** NSFileManager 文件管理对象 ************    //路径    NSString * cachesPath = NSSearchPathForDirectoriesInDomains(NSCachesDirectory, NSUserDomainMask, YES)[0];    NSLog(@"%@",cachesPath);        //创建文件管理对象    NSFileManager * fm = [NSFileManager defaultManager];        //创建文件夹    [fm createDirectoryAtPath:[cachesPath stringByAppendingPathComponent:@"00/test"] withIntermediateDirectories:YES attributes:nil error:nil];        //更改文件名    [fm moveItemAtPath:[cachesPath stringByAppendingPathComponent:@"00/test"] toPath:[cachesPath stringByAppendingPathComponent:@"Demo"] error:nil];        //移动文件位置    [fm moveItemAtPath:[cachesPath stringByAppendingPathComponent:@"00/test"] toPath:[cachesPath stringByAppendingPathComponent:@"Demo/test"] error:nil];    //删除文件    [fm removeItemAtPath:[cachesPath stringByAppendingPathComponent:@"Demo/test"] error:nil];        //判断一个文件是否存在    BOOL i = [fm fileExistsAtPath:@"Demo"];    NSLog(@"%d",i);        }- (void)didReceiveMemoryWarning {    [super didReceiveMemoryWarning];    // Dispose of any resources that can be recreated.}@end

Person.h

#import <Foundation/Foundation.h>//一个类是否可以被归档反归档，要看是否遵循NSCoding协议。@interface Person : NSObject<NSCoding>@property(nonatomic,copy)NSString * name;@property(nonatomic,assign)NSInteger age;@end

Person.m

#import "Person.h"@implementation Person// 编码- (void)encodeWithCoder:(NSCoder *)aCoder{        [aCoder encodeObject:self.name forKey:@"p_name"];        [aCoder encodeInteger:self.age forKey:@"p_age"];}// 反编码- (id)initWithCoder:(NSCoder *)aDecoder{            if (self = [super init]) {                self.name = [aDecoder decodeObjectForKey:@"p_name"];                self.age = [aDecoder decodeIntegerForKey:@"p_age"];            }        return self;    }@end