如何檢測第三次應用程序啓動

Question

我想在第三次啓動應用程序時顯示alertview。我到處搜索，但找不到解決方案。我怎麼知道我的應用第三次啓動？

由於提前

Answer 1

您可以使用這些方法來讀取和寫入用很少的努力

+ (void) setSetting: (NSString *)key value: (NSString *)value { 
NSUserDefaults *defaults = [NSUserDefaults standardUserDefaults]; 
[defaults setObject:value forKey:[NSString stringWithFormat:@"%@", key]]; 
[defaults synchronize]; 
} 

+ (NSString *) getSetting: (NSString *)key defaultVal: (NSString *)defaultVal { 
NSUserDefaults *defaults = [NSUserDefaults standardUserDefaults]; 

NSString *setting = [defaults stringForKey:[NSString stringWithFormat:@"%@", key]]; 
if (setting == nil) { 
    setting = defaultVal; 
} 

return setting; 
} 

你可以每次只需更新一個值，你已經存儲在用戶默認文件中didFinishLaunchingWithOptions:在你的appDelegate被觸發

Answer 2

這很容易。在NSUserDefaults中保存一個NSNumber，並在每次啓動應用程序時增加它。當它命中3時，顯示警報。

Answer 3

- (BOOL)application:(UIApplication *)application didFinishLaunchingWithOptions:(NSDictionary *)options { 
// ... 
if ([self plusPlusLaunchCount] == 3) { 
    [self showRateUsAlert]; 
} 
return YES; 
} 

- (void)showRateUsAlert { 
// show the Rate Us alert view 
} 

- (NSInteger)plusPlusLaunchCount { 
static NSString *Key = @"launchCount"; 
NSInteger count = 1 + [[NSUserDefaults standardUserDefaults] integerForKey:Key]; 
[[NSUserDefaults standardUserDefaults] setInteger:count forKey:Key]; 
return count; 
}