[Objective-C]OC中自定義對象的歸檔基本概念和使用方法(實現NSCoding協議)

平時使用中，我們通常需要通過對自定義對象進行歸檔處理，自定義對象要進行歸檔,需要去實現NSCoding協議.

NSCoding協議有兩個方法，encodeWithCoder方法對對象的屬性數據做編碼處理。

initWithCoder方法解碼歸檔數據來進行初始化對象。

實現NSCoding協議後，就能通過NSKeyedArchiver進行歸檔

下面來看下例子代碼:

Person.h頭文件代碼:

#import 

@interface Person : NSObject 
@property(nonatomic,copy)NSString *name;
@property(nonatomic,copy)NSString *email;
@property(nonatomic,copy)NSString *password;
@property(nonatomic,assign)int age;
@end

#import "Person.h"
#define AGE @"age"
#define NAME @"name"
#define EMAIL @"email"
#define PASSWORD @"password"
@implementation Person
//對對象屬性進行編碼方法
- (void)encodeWithCoder:(NSCoder *)aCoder{
    [aCoder encodeInt:_age forKey:AGE];
    [aCoder encodeObject:_name forKey:NAME];
    [aCoder encodeObject:_email forKey:EMAIL];
    [aCoder encodeObject:_password forKey:PASSWORD];
}
//對對象屬性進行解碼方法
- (id)initWithCoder:(NSCoder *)aDecoder{
    self=[super init];
    if (self!=nil) {
        _age=[aDecoder decodeIntForKey:AGE];
        _name=[[aDecoder decodeObjectForKey:NAME]copy];
        _email=[[aDecoder decodeObjectForKey:EMAIL]copy];
        _password=[[aDecoder decodeObjectForKey:PASSWORD]copy];
        
    }
    return self;
}
-(void)dealloc{
    [_name release];
    [_email release];
    [_password release];
    [super dealloc];
}

#import 
#import "Person.h"
int main(int argc, const char * argv[])
{

    @autoreleasepool {
        Person *person=[[Person alloc]init];
        person.name=@"jack";
        person.age=20;
        person.email=@"[email protected]";
        person.password=@"12345";
        NSString *homePath=NSHomeDirectory();
        NSString *srcPath=[homePath stringByAppendingPathComponent:@"Desktop/person.archiver"];
        BOOL success=[NSKeyedArchiver archiveRootObject:person toFile:srcPath];
        if (success) {
            NSLog(@"歸檔自定義對象成功.");
        }
        
        //還原數據
        Person *result= [NSKeyedUnarchiver unarchiveObjectWithFile:srcPath];
        NSLog(@"name=%@",result.name);
        NSLog(@"age=%d",result.age);
        NSLog(@"email=%@",result.email);
        NSLog(@"password=%@",result.password);
    }
    return 0;
}