我在哪里可以找到 Objective C 的通用游戏状态单例？

Question

我想在 NSCoder 中使用和存储一个游戏状态单例，但我发现很难找到一个通用的状态管理，它使用 NSKeyedArchiver/NSCoder 例程保存和加载其数据。

我想知道是否有人可以指导我找到一个好的教程，或用作游戏状态单例的通用代码，并在 NSCoder 中保存/加载？

谢谢

Answer 1

通过观看 71squared.com 的教程，我已经能够获得一个基本的游戏状态管理器

我使用来自 CocoaWithLove 的 SynthesizeSingleton.h，并且能够使用 NSCoder / 归档保存和加载状态。

由于它使用单格，我可以通过写作来引用它：

GameStateManager *gsm = [GameStateManager sharedGameStateManager];

如下：

// GameStateManager.h file
@interface GameStateManager : NSObject
{
    NSMutableArray *listOfPlayers;
}

@property (nonatomic, retain) NSMutableArray *listOfPlayers;

+ (GameStateManager *)sharedGameStateManager;

-(void)loadGameState;
-(void)saveGameState;

// GameStateManager.m
#import "GameStateManager.h"
#import "SynthesizeSingleton.h"

#import "Player.h"

@implementation GameStateManager
SYNTHESIZE_SINGLETON_FOR_CLASS(GameStateManager)
@synthesize listOfPlayers;

#pragma mark - Init
- (id)init
{
    self = [super init];
    if (self) {
        // Initialization code here.
        self.listOfPlayers = [NSMutableArray array];
    }

    return self;
}

#pragma mark - Memory management

-(void) dealloc
{
    [super dealloc];
}

#pragma mark - Save/Load

-(void)saveGameState
{
    NSLog(@"saveGameState");
    // Set up the game state path to the data file that the game state will be save to
    NSArray *paths = NSSearchPathForDirectoriesInDomains(NSDocumentDirectory, NSUserDomainMask, YES);
    NSString *documentsDirectory = [paths objectAtIndex:0];
    NSString *gameStatePath = [documentsDirectory stringByAppendingPathComponent:@"gameState.dat"];

    // Set up the encoder and storage for the game state data
    NSMutableData *gameData;
    NSKeyedArchiver *encoder;
    gameData = [NSMutableData data];
    encoder = [[NSKeyedArchiver alloc] initForWritingWithMutableData:gameData];

    // Archive the object
    [encoder encodeObject:self.listOfPlayers forKey:@"playerObjects"];

    // Finish encoding and write to disk
    [encoder finishEncoding];
    [gameData writeToFile:gameStatePath atomically:YES];
    [encoder release];
}

-(void)loadGameState
{
    NSLog(@"loadGameState");

    // Set up the game state path to the data file that the game state will be save to
    NSArray *paths = NSSearchPathForDirectoriesInDomains(NSDocumentDirectory, NSUserDomainMask, YES);
    NSString *documentsDirectory = [paths objectAtIndex:0];
    NSString *gameStatePath = [documentsDirectory stringByAppendingPathComponent:@"gameState.dat"];

    NSMutableData *gameData;
    NSKeyedArchiver *decoder;    
    gameData = [NSData dataWithContentsOfFile:gameStatePath];

    // Check to see if the .dat file exists, and load contents
    if (gameData)
    {
        decoder = [[[NSKeyedUnarchiver alloc] initForReadingWithData:gameData] retain];

        self.listOfPlayers = [[[decoder decodeObjectForKey:@"playerObjects"] retain] autorelease];
        NSLog(@"Returned %d players", [self.listOfPlayers count]);

        for (Player *p in self.listOfPlayers) 
        {
            NSLog(@"p.name = %@", p.fname);
        }


        // Finished decoding, release
        [decoder release];
        [decoder autorelease];
    } else {


    }

}

在我的 Player.h/.m 文件中，我这样做：

@interface Player : NSObject
<NSCoding>
{
    NSString *fname;
}
@property(nonatomic,retain) NSString *fname;


// Player.m file
#pragma mark - Encoding

-(id)initWithCoder:(NSCoder *)aDecoder
{
    //[self initWithObject:[aDecoder decodeObject];
    self = [super init];

    if (self) {
        // Initialization code here.
        self.fname = [aDecoder decodeObjectForKey:@"fname"];
    }


    return self;
}

-(void)encodeWithCoder:(NSCoder *)aCoder
{
    [aCoder encodeObject:self.fname forKey:@"fname"];
}

// ---

我的后续问题是：

1) 我是否打算在 GameStateManager 中添加 listOfPlayers？ --> 转到一个新问题

2) 在我的编码器中，我必须单独存储每个字段，不能只存储实际对象本身吗？

3) 对象的编码是否也编码其所有子对象？

假设我有一个父类（玩家）和一个子类（武器）。如果我只对 Player 对象进行编码，它是否会自动对所有武器进行编码，因为它们是链接的？

谢谢。