对象归档

NSString、NSArray、NSData、NSDictionary都实现了NSCoding协议，可直接通过调用writeToFile归档，那么OBJC自定义对象类型呢？首先实现NSCoding协议，重写encodeWithCode方法和initWithCode方法，然后通过NSKeyedArchiver转换为NSData，然后通过NSData的writeToFile方法写入到文件，或者将转换后的NSData放入到NSArray或NSDictionary中调用writeToFile写入到文件便可实现包装了自定义类型的数据和字典的归档；通过NSKeyedUnarchiver读取归档文件到对象，或者通过NSArray的arrrayWithContentsOfFile或NSDictionary的dictionaryWithContentsOfFile到数组对象或字典，然后取出序列化过的自定义对象（即自定义对象的NSData形式），然后通过NSKeyedUnarchiver反归档到对象。

 ------------------------------------------------测试代码------------------------------------------------

 NSString *str = @"hello";
     [str writeToFile:@"/Users/lili/Desktop/str.txt" atomically:YES encoding:NSUTF8StringEncoding error:nil];

     NSArray *arr = [[NSArray alloc]initWithObjects:@"lili",@"tata", nil];
     [arr writeToFile:@"/Users/lili/Desktop/arr.txt" atomically:YES];

     NSDictionary *dict = [NSDictionary dictionaryWithObjects:@[@"lili",@"男"] forKeys:@[@"name",@"sex"]];
     [dict writeToFile:@"/Users/lili/Desktop/dict.txt" atomically:YES];


     Person *parent = [[Person alloc]init];
     parent.age = 40;
     parent.name = @"lili";

     Person *child = [[Person alloc]init];
     child.age = 22;
     child.name = @"linian";

     parent.child = child;

     NSData *data = [NSKeyedArchiver archivedDataWithRootObject:parent];
     [data writeToFile:@"/Users/lili/Desktop/data.txt" atomically:YES];

     Person *people = [NSKeyedUnarchiver unarchiveObjectWithFile:@"/Users/lili/Desktop/data.txt"];
     NSLog(@"%@",people);

     NSDictionary *dictPerson = [NSDictionary dictionaryWithObjects:@[[NSKeyedArchiver archivedDataWithRootObject:parent],[NSKeyedArchiver archivedDataWithRootObject:child]] forKeys:@[@"parent",@"child"]];
     [dictPerson writeToFile:@"/Users/lili/Desktop/dictPerson.txt" atomically:YES];

     NSDictionary *pdict = [NSDictionary dictionaryWithContentsOfFile:@"/Users/lili/Desktop/dictPerson.txt"];
     Person *tPerson = [NSKeyedUnarchiver unarchiveObjectWithData:[pdict objectForKey:@"parent"]];
     NSLog(@"%@",tPerson);



     NSArray *arrPerson = [[NSArray alloc]initWithObjects:[NSKeyedArchiver archivedDataWithRootObject:parent],[NSKeyedArchiver archivedDataWithRootObject:parent], nil];
     [arrPerson writeToFile:@"/Users/lili/Desktop/arrPerson.txt" atomically:YES];

     NSArray *pArr = [NSArray arrayWithContentsOfFile:@"/Users/lili/Desktop/arrPerson.txt"];
     Person *aPerson = [NSKeyedUnarchiver unarchiveObjectWithData:[pArr objectAtIndex:0]];
     NSLog(@"%@",aPerson);


 ------------------------------------------------Person类------------------------------------------------

 #import <Foundation/Foundation.h>
 @interface Person : NSObject<NSCoding>
 @property(strong,nonatomic)Person *child;
 @property(assign,nonatomic)int age;
 @property(copy,nonatomic)NSString *name;
 @end


 #import "Person.h"
 @implementation Person
 -(NSString *)description
 {
     return [NSString stringWithFormat:@"{age:%d,name:%@,child:%@}",self.age,self.name,self.child];
 }

 -(void)encodeWithCoder:(NSCoder *)aCoder
 {
     [aCoder encodeInt:self.age forKey:@"age"];
     [aCoder encodeObject:self.name forKey:@"name"];
     [aCoder encodeObject:self.child forKey:@"child"];
 }

 -(id)initWithCoder:(NSCoder *)aDecoder
 {
     if(self = [super init]){
         self.age = [aDecoder decodeIntForKey:@"age"];
         self.name = [aDecoder decodeObjectForKey:@"name"];
         self.child = [aDecoder decodeObjectForKey:@"child"];
     }
     return self;
 }
 @end