游戏状态单例 cocos2d,initWithEncoder 总是返回 null [英] game state singleton cocos2d, initWithEncoder always returns null
问题描述
我正在尝试在 cocos2d 中编写一个基本的测试游戏状态"单例,但由于某种原因,在加载应用程序时,从未调用过 initWithCoder.任何帮助将不胜感激,谢谢.
I'm trying to write a basic test "game state" singleton in cocos2d, but for some reason upon loading the app, initWithCoder is never called. Any help would be much appreciated, thanks.
这是我的单例 GameState.h:
Here's my singleton GameState.h:
#import "cocos2d.h"
@interface GameState : NSObject <NSCoding>
{
NSInteger level, score;
Boolean seenInstructions;
}
@property (readwrite) NSInteger level;
@property (readwrite) NSInteger score;
@property (readwrite) Boolean seenInstructions;
+(GameState *) sharedState;
+(void) loadState;
+(void) saveState;
@end
... 和 GameState.m:
... and GameState.m:
#import "GameState.h"
#import "Constants.h"
@implementation GameState
static GameState *sharedState = nil;
@synthesize level, score, seenInstructions;
-(void)dealloc {
[super dealloc];
}
-(id)init {
if(!(self = [super init]))
return nil;
level = 1;
score = 0;
seenInstructions = NO;
return self;
}
+(void)loadState {
@synchronized([GameState class]) {
NSArray *paths = NSSearchPathForDirectoriesInDomains(NSDocumentDirectory, NSUserDomainMask, YES);
NSString *documentsDirectory = [paths objectAtIndex:0];
NSString *saveFile = [documentsDirectory stringByAppendingPathComponent:kSaveFileName];
Boolean saveFileExists = [[NSFileManager defaultManager] fileExistsAtPath:saveFile];
if(!sharedState) {
sharedState = [GameState sharedState];
}
if(saveFileExists == YES) {
[sharedState release];
sharedState = [[NSKeyedUnarchiver unarchiveObjectWithFile:saveFile] retain];
}
// at this point, sharedState is null, saveFileExists is 1
if(sharedState == nil) {
// this always occurs
CCLOG(@"Couldn't load game state, so initialized with defaults");
sharedState = [self sharedState];
}
}
}
+(void)saveState {
NSArray *paths = NSSearchPathForDirectoriesInDomains(NSDocumentDirectory, NSUserDomainMask, YES);
NSString *documentsDirectory = [paths objectAtIndex:0];
NSString *saveFile = [documentsDirectory stringByAppendingPathComponent:kSaveFileName];
[NSKeyedArchiver archiveRootObject:[GameState sharedState] toFile:saveFile];
}
+(GameState *)sharedState {
@synchronized([GameState class]) {
if(!sharedState) {
[[GameState alloc] init];
}
return sharedState;
}
return nil;
}
+(id)alloc {
@synchronized([GameState class]) {
NSAssert(sharedState == nil, @"Attempted to allocate a second instance of a singleton.");
sharedState = [super alloc];
return sharedState;
}
return nil;
}
+(id)allocWithZone:(NSZone *)zone
{
@synchronized([GameState class]) {
if(!sharedState) {
sharedState = [super allocWithZone:zone];
return sharedState;
}
}
return nil;
}
...
-(void)encodeWithCoder:(NSCoder *)coder {
[coder encodeInt:level forKey:@"level"];
[coder encodeInt:score forKey:@"score"];
[coder encodeBool:seenInstructions forKey:@"seenInstructions"];
}
-(id)initWithCoder:(NSCoder *)coder {
CCLOG(@"initWithCoder called");
self = [super init];
if(self != nil) {
CCLOG(@"initWithCoder self exists");
level = [coder decodeIntForKey:@"level"];
score = [coder decodeIntForKey:@"score"];
seenInstructions = [coder decodeBoolForKey:@"seenInstructions"];
}
return self;
}
@end
...我正在保存应用退出时的状态,如下所示:
... I'm saving the state on app exit, like this:
- (void)applicationWillTerminate:(UIApplication *)application {
[GameState saveState];
[[CCDirector sharedDirector] end];
}
...并在应用完成加载时加载状态,如下所示:
... and loading the state when the app finishes loading, like this:
- (BOOL) application:(UIApplication *)application didFinishLaunchingWithOptions:(NSDictionary *)launchOptions
{
...
[GameState loadState];
...
}
我也尝试过在我调用 loadState 的地方移动,例如在我的主 CCScene 中,但这似乎也不起作用.
I've tried moving around where I call loadState too, for example in my main CCScene, but that didn't seem to work either.
再次提前致谢.
推荐答案
义不容辞!我想我想通了.另外,我还发现了一个不错的启动宏:http://cocoawithlove.com/2008/11/singletons-appdelegates-and-top-level.html
Righteous! I think I figured it out. Plus I found a nice time-saving macro to boot: http://cocoawithlove.com/2008/11/singletons-appdelegates-and-top-level.html
我正在使用修改后的宏:http://github.com/taberrr/Objective-C-Optimized-Singleton.git(我喜欢sharedGameState"而不是sharedInstance")
And the modified macro I'm using: http://github.com/taberrr/Objective-C-Optimized-Singleton.git (I like "sharedGameState" over "sharedInstance")
希望这会帮助其他人尝试做同样的事情......这是我工作的 NSCoder GameState 单例:
Hopefully this will help someone else trying to do the same thing... here's my working NSCoder GameState singleton:
GameState.h:
#import "SynthesizeSingleton.h"
#import "cocos2d.h"
@interface GameState : NSObject <NSCoding>
{
NSInteger level, score;
Boolean seenInstructions;
}
@property (readwrite) NSInteger level;
@property (readwrite) NSInteger score;
@property (readwrite) Boolean seenInstructions;
SYNTHESIZE_SINGLETON_FOR_CLASS_HEADER(GameState);
+(void)loadState;
+(void)saveState;
@end
GameState.m:
#import "SynthesizeSingleton.h"
#import "GameState.h"
#import "Constants.h"
@implementation GameState
@synthesize level, score, seenInstructions;
SYNTHESIZE_SINGLETON_FOR_CLASS(GameState);
- (id)init {
if((self = [super init])) {
self.level = 1;
self.score = 0;
self.seenInstructions = NO;
}
return self;
}
+(void)loadState
{
@synchronized([GameState class]) {
// just in case loadState is called before GameState inits
if(!sharedGameState)
[GameState sharedGameState];
NSArray *paths = NSSearchPathForDirectoriesInDomains(NSDocumentDirectory, NSUserDomainMask, YES);
NSString *documentsDirectory = [paths objectAtIndex:0];
NSString *file = [documentsDirectory stringByAppendingPathComponent:kSaveFileName];
Boolean saveFileExists = [[NSFileManager defaultManager] fileExistsAtPath:file];
if(saveFileExists) {
// don't need to set the result to anything here since we're just getting initwithCoder to be called.
// if you try to overwrite sharedGameState here, an assert will be thrown.
[NSKeyedUnarchiver unarchiveObjectWithFile:file];
}
}
}
+(void)saveState
{
@synchronized([GameState class]) {
GameState *state = [GameState sharedGameState];
NSArray *paths = NSSearchPathForDirectoriesInDomains(NSDocumentDirectory, NSUserDomainMask, YES);
NSString *documentsDirectory = [paths objectAtIndex:0];
NSString *saveFile = [documentsDirectory stringByAppendingPathComponent:kSaveFileName];
[NSKeyedArchiver archiveRootObject:state toFile:saveFile];
}
}
#pragma mark -
#pragma mark NSCoding Protocol Methods
-(void)encodeWithCoder:(NSCoder *)coder
{
[coder encodeInt:self.level forKey:@"level"];
[coder encodeInt:self.score forKey:@"score"];
[coder encodeBool:self.seenInstructions forKey:@"seenInstructions"];
}
-(id)initWithCoder:(NSCoder *)coder
{
self = [super init];
if(self != nil) {
self.level = [coder decodeIntForKey:@"level"];
self.score = [coder decodeIntForKey:@"score"];
self.seenInstructions = [coder decodeBoolForKey:@"seenInstructions"];
}
return self;
}
@end
保存:
- (void)applicationWillTerminate:(UIApplication *)application {
...
[GameState saveState];
...
}
加载中:
// somewhere in your app, maybe in applicationDidFinishLaunching
GameState *state = [GameState sharedGameState];
NSLog(@"sharedGameState: %@", state);
[GameState loadState];
如果有人对此有任何疑问,请说出来.:)
If someone sees any issues with this, PLEASE speak up. :)
不过,它似乎工作正常.
It appears to work fine, though.
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