我的应用内购买有问题。离开 MasterViewController(列出和购买 IAP 项目的地方)后，我来到 ViewController，它在 viewDidLoad 中检查购买的项目，但我也有一个 viewWillAppear 检查购买的项目并在加载 ViewController 时立即解锁那些购买的项目.

问题是，每次重新加载或刷新 ViewController、离开然后返回时，viewWillAppear 都会检查购买的元素并再次解锁元素，在我的例子中，购买的元素来自 javascript 文件，这恰好多次加载 JS，一遍又一遍地用相同的 IAP 项目使应用程序困惑。

例如，如果您购买了“书签”，则每次重新加载 ViewController 时，您都会一遍又一遍地获得另一个“书签”工具。

如何才能让 IAP 只加载一次？

我的 viewWillAppear 看起来像这样:

- (void)viewWillAppear:(BOOL)animated {
// Check To See If The Uniques IAP Has Been Paid For
if (![[[NSUserDefaults standardUserDefaults] objectForKey:SHOW_UNIQUES_KEY] isEqualToString: @"YES"]){ // NEW CODE
    // Code to show bookmarks

} else {
    NSString *jsString = [NSString stringWithContentsOfURL:[[NSBundle mainBundle] URLForResource:@"Uniques" withExtension:@"js"] encoding:NSUTF8StringEncoding error:nil];
    [viewWeb stringByEvaluatingJavaScriptFromString:jsString];    }
NSLog(@"Shows uniques?: %@", [[NSUserDefaults standardUserDefaults] objectForKey:SHOW_UNIQUES_KEY]);

// Check To See If The PL Numbers IAP Has Been Paid For
if (![[[NSUserDefaults standardUserDefaults] objectForKey:SHOW_PORTAL_LEVEL_KEY] isEqualToString: @"YES"]){ // NEW CODE
    // Code to show bookmarks

} else {
    NSString *jsString = [NSString stringWithContentsOfURL:[[NSBundle mainBundle] URLForResource:@"PortalLevel" withExtension:@"js"] encoding:NSUTF8StringEncoding error:nil];
    [viewWeb stringByEvaluatingJavaScriptFromString:jsString];    }
NSLog(@"Shows portal levels?: %@", [[NSUserDefaults standardUserDefaults] objectForKey:SHOW_PORTAL_LEVEL_KEY]);

// Check To See If The PN IAP Has Been Paid For
if (![[[NSUserDefaults standardUserDefaults] objectForKey:SHOW_PORTALS_KEY] isEqualToString: @"YES"]){ // NEW CODE
    // Code to show bookmarks

} else {
    NSString *jsString = [NSString stringWithContentsOfURL:[[NSBundle mainBundle] URLForResource:@"PortalNames" withExtension:@"js"] encoding:NSUTF8StringEncoding error:nil];
    [viewWeb stringByEvaluatingJavaScriptFromString:jsString];    }
NSLog(@"Shows portal names?: %@", [[NSUserDefaults standardUserDefaults] objectForKey:SHOW_PORTALS_KEY]);

// Check To See If The Bookmarks IAP Has Been Paid For
if (![[[NSUserDefaults standardUserDefaults] objectForKey:SHOW_BOOKMARKS_KEY] isEqualToString: @"YES"]){ // NEW CODE
    // Code to show bookmarks

} else {
    NSString *jsString = [NSString stringWithContentsOfURL:[[NSBundle mainBundle] URLForResource:@"bookmarks" withExtension:@"js"] encoding:NSUTF8StringEncoding error:nil];
    [viewWeb stringByEvaluatingJavaScriptFromString:jsString];    }
NSLog(@"Shows bookmarks?: %@", [[NSUserDefaults standardUserDefaults] objectForKey:SHOW_BOOKMARKS_KEY]);

// Check To See If The Poke A Bowl Ad Has Been Paid For
if (![[[NSUserDefaults standardUserDefaults] objectForKey:SHOW_ADS_KEY] isEqualToString: @"No"]){ // NEW CODE
    // Code to show ads
    _PokeABowlAd.hidden = NO;

} else {
    _PokeABowlAd.hidden = YES;
}
NSLog(@"Shows ads?: %@", [[NSUserDefaults standardUserDefaults] objectForKey:SHOW_ADS_KEY]);
}

最佳答案

我认为你应该做的是让每个人最多被调用一次。您应该使用 NSUserDefaults 来完成此操作。做这样的事情:

将其放入您的 AppDelegate.m 中:

//One new key for each IAP - put at the top of the AppDelegate.m and VC.m
#define IAP_FIRST_USED @"IAP 1 Used"
...
#define IAP_LAST_USED @"IAP X Used"

和

// In applicationDidFinishLaunchingWithOptions, should be the first method listed

[[NSUserDefaults standardUserDefaults] setObject: @"No" forKey: IAP_FIRST_USED];
...
[[NSUserDefaults standardUserDefaults] setObject: @"No" forKey: IAP_LAST_USED];
[[NSUserDefaults standardUserDefaults] synchronize];

然后在 VC.m 中将 viewWillAppear 修改为如下所示(这是第一个 IAP 的示例):

// Check To See If The PL Numbers IAP Has Been Paid For
if (![[[NSUserDefaults standardUserDefaults] objectForKey:SHOW_PORTAL_LEVEL_KEY] isEqualToString: @"YES"]){ // NEW CODE


   // NEW CODE BEGINS HERE

   if ([[[NSUserDefaults standardUserDefaults] objectForKey:IAP_FIRST_USED] isEqualToString: @"No"]){
   [[NSUserDefaults standardUserDefaults] setObject: @"Yes" forKey: IAP_FIRST_USED];
   [[NSUserDefaults standardUserDefaults] synchronize];  
   // Code to show bookmarks



   // End of code to show bookmarks
   // NEW CODE ENDS HERE

   }
} else {
    NSString *jsString = [NSString stringWithContentsOfURL:[[NSBundle mainBundle] URLForResource:@"PortalLevel" withExtension:@"js"] encoding:NSUTF8StringEncoding error:nil];
    [viewWeb stringByEvaluatingJavaScriptFromString:jsString];    
}

还记得在 VC.m 中包含 define 语句

关于ios - 应用内购买后，viewWillAppear 会多次加载已购买的项目，我们在Stack Overflow上找到一个类似的问题： https://stackoverflow.com/questions/31998793/