我们想要长久保存自定义对象数据，那么就少不了对沙盒的操作。
屏幕快照 2017-11-14 下午10.14.03.png
屏幕快照 2017-11-14 下午10.20.12.png
获得路径的方式 Documents , Library , tmp
Documents ： iTunes 会备份，苹果也不允许保存东西在这里面。会被拒
tmp ： 临时保存,随时可能被删除
Library : ----> 下面2个子目录
Caches ：缓存文件
Preferences：偏好设置 保存账号等信息 --> 经过我测试 [NSUserDefaults standardUserDefaults] 就是保存在这里的
//获取Caches路径
NSArray *path1 = NSSearchPathForDirectoriesInDomains(NSCachesDirectory, NSUserDomainMask, YES);
//获取Library路径
NSArray *path2 = NSSearchPathForDirectoriesInDomains(NSLibraryDirectory, NSUserDomainMask, YES);
//获取Documents路径
NSArray *path3 = NSSearchPathForDirectoriesInDomains(NSDocumentDirectory, NSUserDomainMask, YES);
关于归档具体实现1，自定义对象 2， 数组，字典的归档
例子1：字典数组的归档
/**
字典的存取 沙盒路径
*/
-(void)dicArchivie
{
NSString *chahe = [NSSearchPathForDirectoriesInDomains(NSCachesDirectory, NSUserDomainMask, YES) lastObject];
NSString *path = [chahe stringByAppendingString:@"accont.plist"];
NSDictionary *dic = @{@"name":@"xiaoming",@"age":@"18"};
//存
[dic writeToFile:path atomically:YES];
NSLog(@"paths = %@",path);
//取
NSDictionary *dicM = [NSDictionary dictionaryWithContentsOfFile:path];
NSLog(@"dicM = %@",dicM);
}
/*
@interface NSDictionary<__covariant KeyType, __covariant ObjectType> : NSObject <NSCopying, NSMutableCopying, NSSecureCoding, NSFastEnumeration>
这是字典的归档，直接归档到沙盒 cache路径文件下面
从这里可以看出 ，要遵循 NSCoding,NSCopying
*/
例子2：自定义对象的归档解档，我们归档一个person类。
//这是person.h
#import <Foundation/Foundation.h>
@interface Person : NSObject<NSCoding,NSCopying>
@property (nonatomic,copy)NSString *name ;
@property (nonatomic,copy)NSString *age;
@property (nonatomic,assign)CGFloat weight;
@end
//这是person.m 实现
#import "Person.h"
#import <objc/runtime.h>
@interface Person ()
@end
@implementation Person
//方式 1 ，runtime 快速归档
#if 0
//这是runtime 的方法 NSCoding 实现归档的协议
-(void)encodeWithCoder:(NSCoder *)aCoder
{
unsigned int count = 0;
Ivar *ivars = class_copyIvarList([self class], &count); //获取所有的属性
for (int i = 0; i<count; i++) {
//取出变量
Ivar ivar = ivars[i];
//查看变量的名字
NSString *name = [NSString stringWithUTF8String:ivar_getName(ivar)];
//查看变量的类型
//NSString *type = [NSString stringWithUTF8String:ivar_getTypeEncoding(ivar)];
// 利用KVC取出属性对应的值
id value = [self valueForKey:name];
//实现归档
[aCoder encodeObject:value forKey:name];
}
// 记住C语言中copy出来的要进行释放
free(ivars);
}
//解档
-(instancetype)initWithCoder:(NSCoder *)aDecoder
{
if (self =[super init]) {
unsigned int count = 0;
Ivar *ivars = class_copyIvarList([self class], &count);
for (int i = 0; i<count; i++) {
//取出变量
Ivar ivar = ivars[i];
//查看变量的名字
NSString *name = [NSString stringWithUTF8String:ivar_getName(ivar)];
//取出变量的值
id value = [aDecoder decodeObjectForKey:name];
//KVC 赋值
[self setValue:value forKeyPath:name];
}
free(ivars);
}
return self;
}
#endif
//---------------------------------------------------------------------------
//方式2
-(void)encodeWithCoder:(NSCoder *)aCoder
{
[aCoder encodeObject:self.name forKey:@"name"];
[aCoder encodeObject:self.age forKey:@"age"];
[aCoder encodeObject:@(self.weight) forKey:@"weight"];
}
//解档
-(instancetype)initWithCoder:(NSCoder *)aDecoder
{
if (self =[super init]) {
self.name = [aDecoder decodeObjectForKey:@"name"];
self.age = [aDecoder decodeObjectForKey:@"age"];
self.weight = [[aDecoder decodeObjectForKey:@"weight"] doubleValue];
}
return self;
}
//这是ViewController 调用方法
/**
自定义对象的沙盒存取 NSKeyedArchiver 必须用这个
*/
-(void)customObject
{
Person *p = [Person new];
p.name = @"小明";
p.age = @"14";
p.weight = 55;
NSString *chahe = [NSSearchPathForDirectoriesInDomains(NSCachesDirectory, NSUserDomainMask, YES) lastObject];
NSString *path = [chahe stringByAppendingString:@"accton.archive"];
NSLog(@"path = %@",path) ;
//自定义对象的存储必须用 NSKeyedArchiver 不能用 writeToFile
//writeToFile适用 NSArray 和 NSDictionary
[NSKeyedArchiver archiveRootObject:p toFile:path]; //自定义对象 沙盒 存
Person *person = [NSKeyedUnarchiver unarchiveObjectWithFile:path];// 自定义对象 沙盒 取
NSLog(@"%@ %@ %f" ,person.name,person.age,person.weight);
//这里copy Person 必须实现NSCoying
// Person *p1 = [Person mutableCopy];
// NSLog(@"p1.name = %@" ,p1.name);
}
