ios - 应用程序 didFinishLaunchingWithOptions 忽略 if 语句

Question

我在 App Delegate 的 application DidFinishLaunchingWithOptions 中有一个 if 语句。即使 if 语句不正确，if 语句中的代码也会运行。难道我做错了什么？它似乎只是忽略了 if 语句。

- (BOOL)application:(UIApplication *)application didFinishLaunchingWithOptions:(NSDictionary *)launchOptions
{ 
NSInteger i = [[NSUserDefaults standardUserDefaults] integerForKey:@"numOfLCalls"];
[[NSUserDefaults standardUserDefaults] setInteger:i+1 forKey:@"numOfLCalls"];

if (i >= 3) {
    UIAlertView *alert_View = [[UIAlertView alloc] initWithTitle:@"Hey! You are still coming back!" message:@"It would mean a whole lot to me if you rated this app!" delegate:self cancelButtonTitle:@"Maybe later" otherButtonTitles: @"Rate", nil];
    [alert_View show];
}

self.window = [[UIWindow alloc] initWithFrame:[[UIScreen mainScreen] bounds]];
// Override point for customization after application launch.
self.viewController = [[ViewController alloc] initWithNibName:@"ViewController" bundle:nil];
self.window.rootViewController = self.viewController;
[self.window makeKeyAndVisible];
return YES;
}

Answer 1

您将此值存储到 NSUserDefaults 中，当您重建应用程序时它不会被清除。要重置此数字，您必须从模拟器或设备上卸载该应用程序并重新构建。

NSUserDefaults 的要点在于它是真正持久的。即使您的应用程序已从应用程序商店更新，它仍将保留，清除其数据的唯一两种方法是专门有意地删除您引用的 key ，或删除应用程序。

此外，正如您在下面看到的，我为您做了一些细微的调整:

- (BOOL)application:(UIApplication *)application didFinishLaunchingWithOptions:(NSDictionary *)launchOptions
{
    if (![[NSUserDefaults standardUserDefaults] integerForKey:@"numOfLCalls"]) {
        [[NSUserDefaults standardUserDefaults] setInteger:1 forKey:@"numOfLCalls"];
    }else{
        NSInteger i = [[NSUserDefaults standardUserDefaults] integerForKey:@"numOfLCalls"];
        [[NSUserDefaults standardUserDefaults] setInteger:i++ forKey:@"numOfLCalls"];
    }

    if (i >= 3) {
        UIAlertView *alert_View = [[UIAlertView alloc] initWithTitle:@"Hey! You are still coming back!" message:@"It would mean a whole lot to me if you rated this app!" delegate:self cancelButtonTitle:@"Maybe later" otherButtonTitles: @"Rate", nil];
        [alert_View show];
    }

    self.window = [[UIWindow alloc] initWithFrame:[[UIScreen mainScreen] bounds]];
    // Override point for customization after application launch.
    self.viewController = [[ViewController alloc] initWithNibName:@"ViewController" bundle:nil];
    self.window.rootViewController = self.viewController;
    [self.window makeKeyAndVisible];
    return YES;
}