GameCenter 为单机游戏为主的 iPhone 游戏平台引入了社会化特性，更为将来的网游、多人竞技等游戏打下了基础。下面是 CocoaChina 会员 “ljg420811” 总结的 GameCenter 使用指南，包括 GameCenter 的设置和代码实现。
1. iTunes Connect 设置
首先,申请一个应用程序,不必提交.目地是为了得到Bundle ID.
然后设置一下工程中Info.plist的Bundle identifier使之与iTunes Connect中的Bundle ID相同,否则当你尝试登录GameCenter的时候,会提示一个不支持GameCenter的错误.
申请完毕,打开你刚申请的application,点击Manage Game Center选项.
进入后点击Enable Game Center使你的Game Center生效.
接下来就可以设置自己的Leaderboard和Achievements.
2. Leaderboard设置
Leaderboard纵观图如下所示.
1.sort Order: Leaderboard中的内容是以升序还是降序排列.
2.Score Format Type:分数的类型.
3.*Categories:Leaderboard的一个分数榜,这个可以创建多个,比如游戏可以分为Easy,Normal,Hard三个难度,每个难度一个榜.
*设置完成后保存,完成了一个 Leaderboard的设置.我们可以根据需要添加多个 leaderboard.
4.**Score Format Location: leaderboard支持的语言.
**可以支持多种语言,每支持一种语言,需要完成一个上述操作.
这个时候右下角会出现save change按钮,点击完成leaderboard的设置.
你可以根据需要随时更改你的leaderboard,操作与上述内容类似.
3. Achievements设置
Achievements界面内容比较少,点击左上角的Add New Achievement,打开如下图所示的Achievements创建界面.
Hidden:表示该成就为解锁前玩家是否可见.
Achievement ID:程序通过这个属性来识别成就.
*Achievement Localization:该成就支持的语言.
*Achievement Localization设置如下图所示.
*其中,成就的Image必须是512X512,72DPI的.
一切设置完成后,点击save change按钮即完成一个成就的设置.
4.总体功能
在使用各个功能前,你需要了解一下块函数。传送门:https://developer.apple.com/library/ios/#documentation/Cocoa/Conceptual/Blocks/Articles/00_Introduction.html
4.1 对Game Center支持判断
1. - (BOOL) isGameCenterAvailable
2. {
3. Class gcClass = (NSClassFromString(@"GKLocalPlayer"));
4. NSString *reqSysVer = @"4.1";
5. NSString *currSysVer = [[UIDevice currentDevice] systemVersion];
6. BOOL osVersionSupported = ([currSysVer compare:reqSysVer options:NSNumericSearch] != NSOrderedAscending);
7.
8. return (gcClass && osVersionSupported);
9. }
4.2用户登录
1. - (void) authenticateLocalPlayer
2. {
3. [[GKLocalPlayer localPlayer] authenticateWithCompletionHandler:^(NSError *error){
4. if (error == nil) {
5. //成功处理
6. NSLog(@"成功");
7. NSLog(@"1--alias--.%@",[GKLocalPlayer localPlayer].alias);
8. NSLog(@"2--authenticated--.%d",[GKLocalPlayer localPlayer].authenticated);
9. NSLog(@"3--isFriend--.%d",[GKLocalPlayer localPlayer].isFriend);
10. NSLog(@"4--playerID--.%@",[GKLocalPlayer localPlayer].playerID);
11. NSLog(@"5--underage--.%d",[GKLocalPlayer localPlayer].underage);
12. }else {
13. //错误处理
14. NSLog(@"失败 %@",error);
15. }
16. }];
17. }
对于开发者来说,Game Center必须经过测试才能上线,没有上线的程序在测试环境中登录时会出现sandbox提示.如图.
4.3用户变更检测
由于4.0以后系统支持多任务,玩家的机器有可能被不同的玩家接触,导致Game Center上的用户发生变化,当发生变化的时候,程序必须在游戏中通知玩家.
1. - (void) registerForAuthenticationNotification
2. {
3. NSNotificationCenter *nc = [NSNotificationCenter defaultCenter];
4. [nc addObserver:self
5. selector:@selector(authenticationChanged)
6. name:GKPlayerAuthenticationDidChangeNotificationName
7. object:nil];
8. }
9.
10. - (void) authenticationChanged
11. {
12. if ([GKLocalPlayer localPlayer].isAuthenticated)
13. {
14. ;// Insert code here to handle a successful authentication.
15. }
16. else
17. {
18. ;// Insert code here to clean up any outstanding Game Center-related classes.
19. }
20. }
5.对Leaderboard进行操作
5.1上传一个分数
1. - (void) reportScore: (int64_t) score forCategory: (NSString*) category
2. {
3. GKScore *scoreReporter = [[[GKScore alloc] initWithCategory:category] autorelease];
4. scoreReporter.value = score;
5.
6. [scoreReporter reportScoreWithCompletionHandler:^(NSError *error) {
7. if (error != nil)
8. {
9. // handle the reporting error
10. NSLog(@"上传分数出错.");
11. //If your application receives a network error, you should not discard the score.
12. //Instead, store the score object and attempt to report the player’s process at
13. //a later time.
14. }else {
15. NSLog(@"上传分数成功");
16. }
17.
18. }];
19. }
当上传分数出错的时候,要将上传的分数存储起来,比如将SKScore存入一个NSArray中.等可以上传的时候再次尝试.
5.2下载一个分数
1. //GKScore objects provide the data your application needs to create a custom view.
2. //Your application can use the score object’s playerID to load the player’s alias.
3. //The value property holds the actual value you reported to Game Center. the formattedValue
4. //property provides a string with the score value formatted according to the parameters
5. //you provided in iTunes Connect.
6. - (void) retrieveTopTenScores
7. {
8. GKLeaderboard *leaderboardRequest = [[GKLeaderboard alloc] init];
9. if (leaderboardRequest != nil)
10. {
11. leaderboardRequest.playerScope = GKLeaderboardPlayerScopeGlobal;
12. leaderboardRequest.timeScope = GKLeaderboardTimeScopeAllTime;
13. leaderboardRequest.range = NSMakeRange(1,10);
14. leaderboardRequest.category = @"TS_LB";
15. [leaderboardRequest loadScoresWithCompletionHandler: ^(NSArray *scores, NSError *error) {
16. if (error != nil){
17. // handle the error.
18. NSLog(@"下载失败");
19. }
20. if (scores != nil){
21. // process the score information.
22. NSLog(@"下载成功....");
23. NSArray *tempScore = [NSArray arrayWithArray:leaderboardRequest.scores];
24. for (GKScore *obj in tempScore) {
25. NSLog(@" playerID : %@",obj.playerID);
26. NSLog(@" category : %@",obj.category);
27. NSLog(@" date : %@",obj.date);
28. NSLog(@" formattedValue : %@",obj.formattedValue);
29. NSLog(@" value : %d",obj.value);
30. NSLog(@" rank : %d",obj.rank);
31. NSLog(@"**************************************");
32. }
33. }
34. }];
35. }
36. }
说明:
1) playerScope:表示检索玩家分数范围.
2) timeScope:表示某一段时间内的分数
3) range:表示分数排名的范围
4) category:表示你的Leaderboard的ID.
5.3玩家信息交互
Game Center最重要的一个功能就是玩家交互.所以,必须检索已经登录玩家的好友信息.根据自己的需要做出设置,比如,可以与好友比较分数,或者好友排行榜等.
//检索已登录用户好友列表
1. - (void) retrieveFriends
2. {
3. GKLocalPlayer *lp = [GKLocalPlayer localPlayer];
4. if (lp.authenticated)
5. {
6. [lp loadFriendsWithCompletionHandler:^(NSArray *friends, NSError *error) {
7. if (error == nil)
8. {
9. [self loadPlayerData:friends];
10. }
11. else
12. {
13. ;// report an error to the user.
14. }
15. }];
16.
17. }
18. }
上面的friends得到的只是一个身份列表,里面存储的是NSString,想要转换成好友ID,必须调用- (void) loadPlayerData: (NSArray *) identifiers方法,该方法得到的array里面存储的才是GKPlayer对象.如下
1. /*
2. Whether you received player identifiers by loading the identifiers for the local player’s
3. friends, or from another Game Center class, you must retrieve the details about that player
4. from Game Center.
5. */
6. - (void) loadPlayerData: (NSArray *) identifiers
7. {
8. [GKPlayer loadPlayersForIdentifiers:identifiers withCompletionHandler:^(NSArray *players, NSError *error) {
9. if (error != nil)
10. {
11. // Handle the error.
12. }
13. if (players != nil)
14. {
15. NSLog(@"得到好友的alias成功");
16. GKPlayer *friend1 = [players objectAtIndex:0];
17. NSLog(@"friedns---alias---%@",friend1.alias);
18. NSLog(@"friedns---isFriend---%d",friend1.isFriend);
19. NSLog(@"friedns---playerID---%@",friend1.playerID);
20. }
21. }];
22. }
至此,leaderboard功能介绍完毕
6.对Achievement进行操作
这一部分内容比较多,而且有的地方有点重复的感觉.
6.1汇报一个成就的进度
对于一个玩家可见的成就,你需要尽可能的报告给玩家解锁的进度;对于一个一部完成的成就,则不需要,当玩家的进度达到100%的时候,会自动解锁该成就.
1. - (void) reportAchievementIdentifier: (NSString*) identifier percentComplete: (float) percent
2. {
3. GKAchievement *achievement = [[[GKAchievement alloc] initWithIdentifier: identifier] autorelease];
4. if (achievement)
5. {
6. achievement.percentComplete = percent;
7. [achievement reportAchievementWithCompletionHandler:^(NSError *error)
8. {
9. if (error != nil)
10. {
11. //The proper way for your application to handle network errors is retain
12. //the achievement object (possibly adding it to an array). Then, periodically
13. //attempt to report the progress until it is successfully reported.
14. //The GKAchievement class supports the NSCoding protocol to allow your
15. //application to archive an achie
16. NSLog(@"报告成就进度失败 ,错误信息为: \n %@",error);
17. }else {
18. //对用户提示,已经完成XX%进度
19. NSLog(@"报告成就进度---->成功!");
20. NSLog(@" completed:%d",achievement.completed);
21. NSLog(@" hidden:%d",achievement.hidden);
22. NSLog(@" lastReportedDate:%@",achievement.lastReportedDate);
23. NSLog(@" percentComplete:%f",achievement.percentComplete);
24. NSLog(@" identifier:%@",achievement.identifier);
25. }
26. }];
27. }
28. }
其中该函数的参数中identifier是你成就的ID, percent是该成就完成的百分比
6.2读取一个成就
方法一:得到所有的成就
1. - (void) loadAchievements
2. {
3. NSMutableDictionary *achievementDictionary = [[NSMutableDictionary alloc] init];
4. [GKAchievement loadAchievementsWithCompletionHandler:^(NSArray *achievements,NSError *error)
5. {
6. if (error == nil) {
7. NSArray *tempArray = [NSArray arrayWithArray:achievements];
8. for (GKAchievement *tempAchievement in tempArray) {
9. [achievementDictionary setObject:tempAchievement forKey:tempAchievement.identifier];
10. NSLog(@" completed:%d",tempAchievement.completed);
11. NSLog(@" hidden:%d",tempAchievement.hidden);
12. NSLog(@" lastReportedDate:%@",tempAchievement.lastReportedDate);
13. NSLog(@" percentComplete:%f",tempAchievement.percentComplete);
14. NSLog(@" identifier:%@",tempAchievement.identifier);
15. }
16. }
17. }];
18. }
函数中NSArray返回的是你的所有成就ID.
方法二:根据ID获取成就
1. - (GKAchievement*) getAchievementForIdentifier: (NSString*) identifier
2. {
3. NSMutableDictionary *achievementDictionary = [[NSMutableDictionary alloc] init];
4. GKAchievement *achievement = [achievementDictionary objectForKey:identifier];
5. if (achievement == nil)
6. {
7. achievement = [[[GKAchievement alloc] initWithIdentifier:identifier] autorelease];
8. [achievementDictionary setObject:achievement forKey:achievement.identifier];
9. }
10. return [[achievement retain] autorelease];
11. }
6.3获取成就描述和图片
在自定义界面中,玩家需要一个成就描述,以及该成就的图片,Game Center提供了该功能.当然,你也可以自己在程序中完成,毕竟玩家不可能时刻处于在线状态.
1. - (NSArray*)retrieveAchievmentMetadata
2. {
3. //读取成就的描述
4. [GKAchievementDescription loadAchievementDescriptionsWithCompletionHandler:
5. ^(NSArray *descriptions, NSError *error) {
6. if (error != nil)
7. {
8. // process the errors
9. NSLog(@"读取成就说明出错");
10. }
11. if (descriptions != nil)
12. {
13. // use the achievement descriptions.
14. for (GKAchievementDescription *achDescription in descriptions) {
15. NSLog(@"1..identifier..%@",achDescription.identifier);
16. NSLog(@"2..achievedDescription..%@",achDescription.achievedDescription);
17. NSLog(@"3..title..%@",achDescription.title);
18. NSLog(@"4..unachievedDescription..%@",achDescription.unachievedDescription);
19. NSLog(@"5............%@",achDescription.image);
20.
21. //获取成就图片,如果成就未解锁,返回一个大文号
22. /*
23. [achDescription loadImageWithCompletionHandler:^(UIImage *image, NSError *error) {
24. if (error == nil)
25. {
26. // use the loaded image. The image property is also populated with the same image.
27. NSLog(@"成功取得成就的图片");
28. UIImage *aImage = image;
29. UIImageView *aView = [[UIImageView alloc] initWithImage:aImage];
30. aView.frame = CGRectMake(50, 50, 200, 200);
31. aView.backgroundColor = [UIColor clearColor];
32. [[[CCDirector sharedDirector] openGLView] addSubview:aView];
33. }else {
34. NSLog(@"获得成就图片失败");
35. }
36. }];
37. */
38. }
39. }
40. }];
41. return nil;
42. }
如果你不主动使用注释中的方法,那么你得到的description中不会有图片,这样可以减少网络的使用,尽量少下载东西.当使用注释中的代码时,如果成就已经解锁,则返回该成就的图标,如果没有解锁,则返回一个大问号,至于未解锁图标是否可以自定义,我找寻的结果好像是不可以.