Gamekit is a framework that provides leader board, achievements, and more features to an iOS application. In this chapter, we will be discussing the steps involved in adding a leader board and updating the score.
Steps Involved
- Step 1. In iTunes connect, ensure that we have a unique App ID and when we create the application update with the bundle ID and code signing in Xcode with corresponding provisioning profile.
- Step 2. We need to create a new application and update application information. We can know more about this in apple-add new apps documentation.
- Step 3. We need toSetup a leader board in Manage Game Center of our application’s page where add a single leaderboard and give leaderboard ID and score Type. Here we give leader board ID as WisdomJobs.
- Step 4. The next steps are related to handling code and creating UI for our application.
- Step 5. We need toCreate a single view application and enter the bundle identifier is the identifier specified in iTunes connect.
- Step 6.We need to update the ViewController.xib as displayed below −
- Step 7. Select our project file, then select targets and then add GameKit.framework.
- Step 8. Create IBActions for the buttons we have added.
- Step 9. Update the ViewController.h file as below−
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#import <UIKit/UIKit.h>
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#import <GameKit/GameKit.h>
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@interface ViewController : UIViewController
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<GKLeaderboardViewControllerDelegate>
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-(IBAction)updateScore:(id)sender;
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-(IBAction)showLeaderBoard:(id)sender;
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@end
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- Step 10. Update ViewController.m as follows −
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#import "ViewController.h"
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@interface ViewController ()
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@end
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@implementation ViewController
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- (void)viewDidLoad
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{
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[super viewDidLoad];
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if([GKLocalPlayer localPlayer].authenticated == NO)
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{
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[[GKLocalPlayer localPlayer]
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authenticateWithCompletionHandler:^(NSError *error)
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{
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NSLog(@"Error%@",error);
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}];
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}
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}
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- (void)didReceiveMemoryWarning
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{
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[super didReceiveMemoryWarning];
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// Dispose of any resources that can be recreated.
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}
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- (void) updateScore: (int64_t) score
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forLeaderboardID: (NSString*) category
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{
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GKScore *scoreObj = [[GKScore alloc]
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initWithCategory:category];
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scoreObj.value = score;
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scoreObj.context = 0;
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[scoreObj reportScoreWithCompletionHandler:^(NSError *error) {
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// Completion code can be added here
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UIAlertView *alert = [[UIAlertView alloc]
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initWithTitle:nil message:@"Score Updated Succesfully"
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delegate:self cancelButtonTitle:@"Ok" otherButtonTitles: nil];
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[alert show];
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}];
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}
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-(IBAction)updateScore:(id)sender{
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[self updateScore:200 forLeaderboardID:@"wisdomjobs"];
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}
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-(IBAction)showLeaderBoard:(id)sender{
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GKLeaderboardViewController *leaderboardViewController =
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[[GKLeaderboardViewController alloc] init];
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leaderboardViewController.leaderboardDelegate = self;
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[self presentModalViewController:
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leaderboardViewController animated:YES];
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}
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#pragma mark - Gamekit delegates
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- (void)leaderboardViewControllerDidFinish:
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(GKLeaderboardViewController *)viewController{
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[self dismissModalViewControllerAnimated:YES];
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}
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@end
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Output
On running the application, we’ll get the below output-
On clicking “show leader board”, we will be getting a screen, which is similar to the below screen −
On clicking “update score”, the score will get updated to our leader board and we will get an alert as displayed below −
