正在NSMutableData中加载层次结构

Question

NSMutableData中是否存在层次结构系统？如果是，我如何以层次结构的方式加载信息？示例

//Create path to saving location
NSArray *paths = NSSearchPathForDirectoriesInDomains(NSDocumentDirectory, NSUserDomainMask, YES);
NSString *documentsDirectory = [paths objectAtIndex:0];
NSMutableData *gameData;
NSKeyedUnarchiver *decoder;
NSString *documentPath = [documentsDirectory stringByAppendingPathComponent:@"tierSave.dat"];
gameData = [NSData dataWithContentsOfFile:documentPath];
//end
//start loading
    for(NSArray* firstData in gameData){
    decoder = [[NSKeyedUnarchiver alloc] initForReadingWithData:gameData];
    int level1 = [decoder decodeIntegerForKey:level1];
    }
//end

然而，对于（在gameData中的NSArray*firstData），编译器告诉我gameData不会响应计数，因为它是NSMutableData而不是NSMutabbleArray等，我如何准确地重新实现上面的代码？

Answer 1

保存：

• 使用多个NSData创建NSArray
• 使用NSKeyedArchiver从NSArray生成NSData

装载：

• 从文件加载NSData
• 使用NSKeyedUnarchiver提取NSArray
• 循环你的NSArray

代码中：NSData*data0=[NSData数据]；//数据1NSData*data1=[NSData数据]；//数据2

/////////// SAVE
// now make a array
NSArray *array = [NSArray arrayWithObjects:data0, data1, nil];
// now archive the data
NSData *archivedData = [NSKeyedArchiver archivedDataWithRootObject:array];
// archivedData contains now a binary plist with your archived array including your NSData objects
[archivedData writeToFile:path atomically:YES];

/////// LOAD
NSData *archivedDataFromFile = [NSData dataWithContentsOfFile:path];
NSArray *newArray = [NSKeyedUnarchiver unarchiveObjectWithData:archivedDataFromFile];
NSData *dataLoaded0 = [newArray objectAtIndex:0];