NSUserDefaults和alertView

Question

我正在创建一个免责声明，将在用户首次启动应用程序时显示。免责声明是具有2个选项的alertView。如果用户同意，则将显示firstViewController。如果他不这样做，他将被重定向到另一个viewController。但是如果用户第一次同意，我不能让免责声明消失。它在应用程序每次启动时都会显示。任何帮助都将不胜感激。提前谢谢你..

NSUserDefaults *defaults = [NSUserDefaults standardUserDefaults];

      if (![[defaults valueForKey:@"keyDisclaimer"] isEqualToString:@"accepted"]) {

UIAlertView *disclaimer = [[UIAlertView alloc] initWithTitle:@"Read Before use" message:@"By using this app you agree to its terms and conditions.\n\n\n\n\n\n\n\n\n\n\ntext heren\n\n\n\n\n\n\n\n\n\n\n\n\n" delegate:self cancelButtonTitle:@"No!" otherButtonTitles:@"Yes Let me In", nil];

[disclaimer show];

}

// Override point for customization after application launch.
return YES;
}

-(void) alertView:(UIAlertView *) alertView clickedButtonAtIndex:(NSInteger)buttonIndex{
NSString *buttonString = {[alertView buttonTitleAtIndex:buttonIndex]};

if ([buttonString isEqualToString:@"Yes Let me In"]) {
    NSMutableDictionary* defaultValues = [NSMutableDictionary dictionary];

    [defaultValues setValue:@"accepted"forKey:@"keyDisclaimer"];

    [[NSUserDefaults standardUserDefaults] registerDefaults:defaultValues];



}
else if ([buttonString isEqualToString:@"No!"]) {
    UIAlertView *alert = [[UIAlertView alloc] initWithTitle:@"Sorry!" message:@"You are not allowed to use this app due to the fact that you did not agree to the terms and Conditions. Please exit this app!" delegate:self cancelButtonTitle:@"OK" otherButtonTitles:nil, nil];
    [alert show];

 //  [[NSUserDefaults standardUserDefaults] setValue:@"notAccepted" forKey:@"keyDisclaimer"];
 }

   if ([buttonString isEqualToString:@"OK"]) {
       introViewController *intro = [[introViewController alloc] initWithNibName:@"introViewController" bundle:nil];

      _window = [[UIWindow alloc] initWithFrame:[[UIScreen mainScreen] bounds]];

       _window.rootViewController = intro;
       [_window makeKeyAndVisible];
   }
 }

Answer 1

NSMutableDictionary* defaultValues = [NSMutableDictionary dictionary]; 
[defaultValues setValue:...forKey:...]
[[NSUserDefaults standardUserDefaults] registerDefaults:defaultValues];

这将注册您的默认值，如果它们没有设置(第一次)

此外，您似乎忘记了[defaults synchronize]在设置值之后提交更改。如果是这样的话，您根本不需要registerDefaults方法。

如下所示：

if ([buttonString isEqualToString:@"Yes Let me In"]) {
    NSUserDefaults* defaults = [NSUserDefaults standardUserDefaults];
    [defaults setValue:@"accepted"forKey:@"keyDisclaimer"];
    [defaults synchronize];
}

Answer 2

您希望使用stringForKey或objectForKey之类的内容，而不是valueForKey。

if([[defaults stringForKey:@"keyDisclaimer"] isEqualToString:@"accepted"]) {

我过去在使用valueForKey时有过不好的经历，并不总是按照我想要的方式工作。这可能就是给你带来问题的原因。