• 所謂歸檔:將複雜物件轉化為NSData型別資料(複雜-->歸檔-->NSData--->WriteToFile)
  注意:歸檔是將物件轉化為資料位元組,以檔案的形式儲存在磁碟上,

• 所謂反歸檔:將NSData型別資料轉化為複雜物件(讀取檔案-->NSData-->反歸檔--->複雜物件)

  再說歸檔之前,先說下iOS的資料持久化方式:
  那麼問題來了,什麼是資料持久化?

  資料持久化(俠義的理解):僅僅指把域物件永久儲存到資料庫中,(廣義的理解):包括和資料庫相關的各種操作
  優點:
  1:資料持久化可以減少訪問資料庫資料的次數,增加應用程式執行的速度;
  2:程式碼重用性高,能夠完成大部分資料庫操作;
  3:低耦合,使持久化不依賴於底層資料庫和上層業務邏輯實現,更換資料庫時只需要修改配置檔案而不用修改程式碼

那麼iOS的資料化持久方式有哪些呢?

1:屬性列表(Plist檔案),NSUserDefault
2:歸檔(NSKeyedArchiver)
3:資料庫(SQlite,CoreData,FMDB(第三方))

今天重點說下歸檔和結檔的問題
歸檔的三種方式:

1:對foundation框架的物件進行歸檔
2:對自定義的物件進行歸檔
3:對自定義內容進行歸檔
注意:歸檔生成的檔案是加密的

下邊舉簡單的例子分別說下歸檔的三種方式

#pragma mark---對自定義物件進行歸檔反歸檔----
- (void)archive{
//先建立一個Person類
/*
 第一:複雜物件所屬的類一定要遵循NSCoding協議
 第二:實現協議中的方法
 - (void)encodeWithCoder:(NSCoder *)aCoder;
 - (instancetype)initWithCoder:(NSCoder *)aDecoder;
//歸檔(由叫序列化)的步驟
//對Person類物件進行歸檔時執行此方法.並對Person類中想要進行歸檔的所有屬性,進行序列化操作

- (void)encodeWithCoder:(NSCoder *)aCoder{
    [aCoder encodeObject:_name forKey:@"name"];
    [aCoder encodeObject:_gender forKey:@"gender"];
    [aCoder encodeObject:_age forKey:@"age"];
}

//反歸檔(由叫反序列化)的步驟
//對Person類物件進行反歸檔時執行此方法.並對Person類中想要進行反歸檔的所有屬性,進行反序列化操作
- (instancetype)initWithCoder:(NSCoder *)aDecoder{
    if (self = [super init]) {
        _name = [aDecoder decodeObjectForKey:@"name"];
        _gender = [aDecoder decodeObjectForKey:@"gender"];
        _age = [aDecoder decodeObjectForKey:@"age"];
    }
        return self;

}

 */
 


    person *per = [person new];
    per.name = @"甲甲";
    per.age = @"20";
    per.gender = @"女";

    //歸檔
    //1:準備路徑
    NSString *path = NSHomeDirectory();
    path = [path stringByAppendingString:@"Singel.plist"];
    //2:準備儲存資料物件(用可變陣列進行接收)
    NSMutableData *data = [NSMutableData new];
    //3:建立歸檔物件
 

    NSKeyedArchiver *archiver = [[NSKeyedArchiver alloc]initForWritingWithMutableData:data];
    //4:開始歸檔
    [archiver encodeObject:per forKey:@"person"];
    //5:完成歸檔
    [archiver finishEncoding];
    //6:寫入檔案
    BOOL result = [data writeToFile:path atomically:YES];
    if (result) {
        NSLog(@"歸檔成功:%@",path);
    }

    //反歸檔
    //1:獲取解檔路徑
    NSData *MyData = [NSData dataWithContentsOfFile:path];
    //2:建立反歸檔物件
    NSKeyedUnarchiver  *unarchiver= [[NSKeyedUnarchiver alloc]initForReadingWithData:MyData];
    //3:反歸檔
    person *aper = [person new];
    aper = [unarchiver decodeObjectForKey:@"person"];
    //4:結束歸檔
    [unarchiver finishDecoding];
    NSLog(@"%@",aper.name);
}

#pragma mark----對foundation框架中的物件進行歸檔和反歸檔
- (void)fundationClass{
//歸檔
    //1:建立路徑
    NSString *Doucuments = [NSSearchPathForDirectoriesInDomains(NSDocumentDirectory, NSUserDomainMask, YES)firstObject];
    NSString *path = [Doucuments stringByAppendingString:@"file.plist"];
    //2:歸檔(不需要結束方法)
    NSArray *array = @[@"jiajia",@"jiejie",@"pangpang"];
    BOOL result = [NSKeyedArchiver archiveRootObject:array toFile:path];
    if (result) {
        NSLog(@"框架中的歸檔%@",path);
    }
    //反歸檔
    NSArray *newArray = [NSKeyedUnarchiver unarchiveObjectWithFile:path];
    NSLog(@"框架的結檔%@",newArray);
}

#pragma mark----對自定義的內容進行歸檔和反歸檔
- (void)customContent{
//歸檔
    //1:獲取路徑

    NSString *path = [NSSearchPathForDirectoriesInDomains(NSDocumentDirectory, NSUserDomainMask, YES)firstObject];

   path = [path stringByAppendingString:@"custom.plist"];

    NSMutableData *data = [NSMutableData data];

    NSKeyedArchiver *archiver = [[NSKeyedArchiver alloc]initForWritingWithMutableData:data];

    [archiver encodeObject:@"111" forKey:@"name"];
    [archiver encodeObject:@"2" forKey:@"gender"];
    [archiver encodeObject:@"100" forKey:@"age"];

    [archiver finishEncoding];

    BOOL result = [data writeToFile:path atomically:YES];
    if (result) {
        NSLog(@"歸檔%@",path);
    }
    NSData *newdata = [NSData dataWithContentsOfFile:path];
    NSKeyedUnarchiver *unkeyed =  [[NSKeyedUnarchiver alloc]initForReadingWithData:newdata];
//    NSString *str1 = [unkeyed decodeObjectForKey:@"name"];
//    NSString *str2 = [unkeyed decodeObjectForKey:@"gender"];
//    NSString *str3 = [unkeyed decodeObjectForKey:@"age"];

    person *pp = [person new];
    pp.name = [unkeyed decodeObjectForKey:@"name"];
    pp.gender = [unkeyed decodeObjectForKey:@"gender"];
    pp.age = [unkeyed decodeObjectForKey:@"age"];
    [unkeyed finishDecoding];
    NSLog(@"name:%@ gender:%@ age:%@",pp.name,pp.gender,pp.age);
//    NSLog(@"name:%@ gender:%@ age:%@",str1,str2,str3);

}