【非凡程序员】 OC第十七节课 文件操作二 （归档和解档)

//-----------------------------归档和解档-----（重点）-------、-----------//
        //可变的文件流
        NSMutableData *nutabdata=[[NSMutableData alloc]init];
        //把用归档格式的数据值给可变的文件流
        NSKeyedArchiver *keyde=[[NSKeyedArchiver alloc]initForWritingWithMutableData:nutabdata];
        //把集合形式以归档对形式编码
        [keyde encodeObject:dict forKey:@"suisui"];
        //完成归档
        [keyde finishEncoding];
       
        //把归档过来的可变大小的数据流 写入文件中，永久存储
        [nutabdata writeToFile:@"/Users/feifanchengxuyuan/Desktop/Friday3.plist" atomically:YES];
       
        // 实例化一个解档对象  注意：初始化为解档格式并要放入药解档的数据流
        NSKeyedUnarchiver *unkeyed=[[NSKeyedUnarchiver alloc]initForReadingWithData:nutabdata];
        NSArray *nasrr=[unkeyed decodeObjectForKey:@"suisui"];
        NSLog(@"%@",nasrr);
        [nasrr writeToFile:@"/Users/feifanchengxuyuan/Desktop/Friday3.plist"  atomically:YES];

//第二次打开时－－解档
        [[unkeyed decodeObjectForKey:@"suisui"]writeToFile:@"/Users/feifanchengxuyuan/Desktop/Friday3.plist" atomically:YES];
        NSString *yy=[NSString stringWithContentsOfFile:@"/Users/feifanchengxuyuan/Desktop/Friday3.plist" encoding:NSUTF8StringEncoding error:nil];
        NSLog(@"----%@",yy);
    
        
    }