Object-C-系统类型对象归档

系统类型主要是指NSString NSDictionary,NSArray,NSData，NSNumber 类型数据（包括对应可变类型);

这些类型已经实现了NSCoding协议，支持归档,

写入方法:

writeToFile:atomically:

读取方法：

-dictionaryWithContentsOfFile:

-arrayWithContentsOFFile:

-dataWithContentsOfFile:

-stringWithContentsOfFile:

//字符串对象归档以及解归档 atomically 缓冲池
    NSString *str=@"hello oc!";
    
    
     //写入
    BOOL falg=[str writeToFile:@"str.txt" atomically:YES encoding:NSUTF8StringEncoding error:nil];
    if(falg){
        NSLog(@"str 保存成功！");
    }
    
    //读取
    NSString *readStr=[NSString stringWithContentsOfFile:@"str.txt" encoding:NSUTF8StringEncoding error:nil];
    
    //数组对象归档以及解归档
    //写入
    NSArray *arr=@[@"one",@"two",@"three"];
    BOOL flag=[arr writeToFile:@"arr.plist" atomically:YES];
    if(flag){
        NSLog(@"YES");
    }

   //读出
    NSArray *readArr =[NSArray arrayWithContentsOfFile:@"arr.plist"];
   
    //字典对象归档以及解归档
    NSDictionary *dic=@{@"1":@"one",
                        @"2":@"two",
                        @"3":@"three"};
    //写入
    BOOL flag = [dic writeToFile:@"dic.plist" atomically:YES];
    if(flag){
        NSLog(@"YES");
    }
     
    NSDictionary *readDic = [NSDictionary dictionaryWithContentsOfFile:@"dic.plist"];
    NSLog(@"readDic = %@",readDic);