首页 > 代码库 > iOS - 集成game center (leader board)

iOS - 集成game center (leader board)

最近又一次用到game center里面的leader board。其实这个事情很简单,只是很容易忘记。所以就打算写下来。


iTunes Connect上创建app,然后启用game center

创建app就省略了,等创建成功后,不需要提交。我们就可以设置game center了。

首先点击新建的app,找到Game Center,如图

技术分享


点击进入具体的game center设置,可以添加一些项目。很是简单,基本上都有提示,需要注意的是排行榜id,得搞个独立的,不要重复。这个id在代码里面需要使用。

就这么简单的搞几下,game center就启用了。

技术分享


在代码中引入game center

在xcode的工程里面打开game center,

技术分享



直接打开就行,感觉ios开发越来越傻瓜了,呵呵。

接下来就是具体的代码实现了。


代码实现

首先在合适的地方添加如下代码:通常是

- (BOOL)application:(UIApplication *)application didFinishLaunchingWithOptions:(NSDictionary *)launchOptions

double ver = [[UIDevice currentDevice].systemVersion doubleValue];
    if (ver < 6.0) {
        [[GKLocalPlayer localPlayer] authenticateWithCompletionHandler:^(NSError *error) {
            
        }];
    }
    else
    {
        [[GKLocalPlayer localPlayer] setAuthenticateHandler:(^(UIViewController* viewcontroller, NSError *error) {
            
        })];
    }
    
    NSNotificationCenter* ns = [NSNotificationCenter defaultCenter];
    
    [ns addObserver:self selector:@selector(authenticationChanged) name:GKPlayerAuthenticationDidChangeNotificationName object:nil];

    
我们给game center增加了一个观察者,所以就需要在self里面提供一个函数。这是一个回调函数,如果用户没有登录game center,那么就会跑到下面,如果登陆了就会跑到上面。
- (void) authenticationChanged
{
    if ([GKLocalPlayer localPlayer].isAuthenticated) {
        NSLog(@"authenticationChanged, authenticated");
        
        
        
    }
    else
    {
        
        NSLog(@"authenticationChanged, Not authenticated");
    }
}

接下来就是提交和显示leader board了。具体的说明苹果的官网上说的很清楚。我这里在网上找到一个封装的源代码,自己稍微修改了一下。具体代码看最后面(附)。这里主要介绍使用流程。先增加一个属性。

@property (readwrite, retain) PlayerModel * player;
再增加一个函数,如:

- (void) updatePlayer
{
    
    if (!self.player || ![self.player.currentPlayerID isEqualToString:[GKLocalPlayer localPlayer].playerID]) {
        
        [self.player release];
        
        self.player = [[PlayerModel alloc] init];
    }
    [[self player] loadStoredScores];
}
这个函数会在authenticationChanged里面被调到。

- (void) authenticationChanged
{
    if ([GKLocalPlayer localPlayer].isAuthenticated) {
        NSLog(@"authenticationChanged, authenticated");
        
        [self updatePlayer];
    }
    else
    {
        NSLog(@"authenticationChanged, Not authenticated");
    }
}
updatePlayer这个函数比较关键。

它支持多用户,如果是第一次登陆game center,那么就创建一个对象,如果是换了个用户登录,那么就把之前的释放,然后创建一个新的对象。然后调用loadStoredScore.

loadStoredScore会从本地文件里面读取需要传送的分数,并且往game center服务器传。

上面这段代码的意思就是app起来后,authenticationChanged被调用了,如果是登录的状态,那么就会创建一个PlayerModel对象。如果有需要上传的数据,那么就读取并且尝试上传。

其实这是个保护措施,后面会讲到为什么需要这么做。


接下来就看看如果在游戏中即时上传数据。

首先增加一个函数,这个函数就是往服务器发送数据。self.player submitScore,这个函数会在后面看到。有了这个函数,我们在游戏或者应用的某个地方可以调用往服务器发送数据了。LEADERBOARD_DISTANCE的值就是上面connect里面创建的那个排行榜id。

- (void) storeScore:(NSNumber *)distance
{
    if (!self.player)
        return;
    
    int64_t score64 =  [distance longLongValue];
    GKScore * submitScore = [[GKScore alloc] initWithCategory:LEADERBOARD_DISTANCE];
    [submitScore setValue:score64];
    [self.player submitScore:submitScore];
    [submitScore release];
}

ok,就这么简单。现在就大概讲讲PlayerModel的原理。因为我们在提交的时候往往会因为网络原因而失败,特别在中国。所以,PlayerModel里面就提交了一个机制,如果提交失败,就把要提交的数据保存到本地文件,在合适的时候再尝试提交。

- (void)submitScore:(GKScore *)score 
{
    if ([GKLocalPlayer localPlayer].authenticated) {
        if (!score.value) {
            // Unable to validate data. 
            return;
        }
        
        // Store the scores if there is an error. 
        [score reportScoreWithCompletionHandler:^(NSError *error){
            if (!error || (![error code] && ![error domain])) {
                // Score submitted correctly. Resubmit others
                [self resubmitStoredScores];
            } else {
                // Store score for next authentication. 
                [self storeScore:score];
            }
        }];
    } 
}
这个函数的主要意思就是,先尝试提交数据,如果成功,那么随便提交一下其他的数据(可能之前提交失败了)。如果失败,那么就把数据保存下来[self storeScore: score],保存到一个array,并且写入本地文件。这样就有机会在其他地方再提交一次。完整代码看后面。

现在就看看如果在app里面显示leader board。看下面的代码gameCenterAuthenticationComplete是我内部使用的一个bool,用来标记用户是否登录了game center。调用一下这个代码,就会显示iOS的game center。

- (void) showGameCenter
{
    if (gameCenterAuthenticationComplete) {
        GKLeaderboardViewController * leaderboardViewController = [[GKLeaderboardViewController alloc] init];
        [leaderboardViewController setCategory:LEADERBOARD_DISTANCE];
        [leaderboardViewController setLeaderboardDelegate:_viewController];
        [self.viewController presentModalViewController:leaderboardViewController  animated:YES];
        [leaderboardViewController release];
    }
}


附,完整PlayerModle代码:

header file:

#import <Foundation/Foundation.h>
#import <GameKit/GameKit.h>

@interface PlayerModel : NSObject {
	NSLock *writeLock;
}

@property (readonly, nonatomic) NSString* currentPlayerID;
@property (readonly, nonatomic) NSString *storedScoresFilename;
@property (readonly, nonatomic) NSMutableArray * storedScores;

// Store score for submission at a later time.
- (void)storeScore:(GKScore *)score ;

// Submit stored scores and remove from stored scores array.
- (void)resubmitStoredScores;

// Save store on disk. 
- (void)writeStoredScore;

// Load stored scores from disk.
- (void)loadStoredScores;

// Try to submit score, store on failure.
- (void)submitScore:(GKScore *)score ;

@end


m file:

#import "PlayerModel.h"

@implementation PlayerModel

@synthesize storedScores,
            currentPlayerID,
            storedScoresFilename;

- (id)init
{
    self = [super init];
    if (self) {
        currentPlayerID = [[NSString stringWithFormat:@"%@", [GKLocalPlayer localPlayer].playerID] retain];
        NSString* path = [NSSearchPathForDirectoriesInDomains(NSDocumentDirectory, NSUserDomainMask, YES) objectAtIndex:0];
        storedScoresFilename = [[NSString alloc] initWithFormat:@"%@/%@.storedScores.plist",path, currentPlayerID];
        writeLock = [[NSLock alloc] init];
    }
    return self;
}

- (void)dealloc
{
    [storedScores release];
    [writeLock release];
    [storedScoresFilename release];
    [currentPlayerID release];
    
    [super dealloc];
}

// Attempt to resubmit the scores.
- (void)resubmitStoredScores
{
    if (storedScores) {
        // Keeping an index prevents new entries to be added when the network is down 
        int index = (int)[storedScores count] - 1;
        while( index >= 0 ) {
            GKScore * score = [storedScores objectAtIndex:index];
            [self submitScore:score];
            [storedScores removeObjectAtIndex:index];
            index--;
        }
        [self writeStoredScore];
    }
}

// Load stored scores from disk.
- (void)loadStoredScores
{
    NSArray *  unarchivedObj = [NSKeyedUnarchiver unarchiveObjectWithFile:storedScoresFilename];
    
    if (unarchivedObj) {
        storedScores = [[NSMutableArray alloc] initWithArray:unarchivedObj];
        [self resubmitStoredScores];
    } else {
        storedScores = [[NSMutableArray alloc] init];
    }
}


// Save stored scores to file. 
- (void)writeStoredScore
{
    [writeLock lock];
    NSData * archivedScore = [NSKeyedArchiver archivedDataWithRootObject:storedScores];
    NSError * error;
    [archivedScore writeToFile:storedScoresFilename options:NSDataWritingFileProtectionNone error:&error];
    if (error) {
        //  Error saving file, handle accordingly 
    }
    [writeLock unlock];
}

// Store score for submission at a later time.
- (void)storeScore:(GKScore *)score 
{
    [storedScores addObject:score];
    [self writeStoredScore];
}

// Attempt to submit a score. On an error store it for a later time.
- (void)submitScore:(GKScore *)score 
{
    if ([GKLocalPlayer localPlayer].authenticated) {
        if (!score.value) {
            // Unable to validate data. 
            return;
        }
        
        // Store the scores if there is an error. 
        [score reportScoreWithCompletionHandler:^(NSError *error){
            if (!error || (![error code] && ![error domain])) {
                // Score submitted correctly. Resubmit others
                [self resubmitStoredScores];
            } else {
                // Store score for next authentication. 
                [self storeScore:score];
            }
        }];
    } 
}

@end













iOS - 集成game center (leader board)