Question

我是一个想要在我的应用程序中存储int值（高分）的初学者，所以当用户从多任务关闭应用程序并再次打开它时，它将获取数据并显示它。

我尝试使用NSUserDefaults，但是当我再次打开应用程序时它不会出现。这是我使用的代码：

// Used this to load the high score from the memory
  highscoreInt = (int)[[NSUserDefaults standardUserDefaults] integerForKey:@"highscore"]; 

// And this to store it, later in the code
- (void)applicationWillTerminate:(UIApplication *)application
{
    [[NSUserDefaults standardUserDefaults] setInteger:highscoreInt forKey:@"highscore"];
    [[NSUserDefaults standardUserDefaults] synchronize];
}

Answer 1

我会将整数包装在NSNumber对象中，并将其放在applicationDidEnterBackground中，如下所示：

// Use this method to release shared resources, save user data, 
// invalidate timers, and store enough application state information to 
// restore your application to its current state in case it is terminated later.

- (void)applicationDidEnterBackground:(UIApplication *)application
{
  highscoreInt = (int)[[NSUserDefaults standardUserDefaults] integerForKey:@"highscore"]; 

  [[NSUserDefaults standardUserDefaults] setObject:[NSNumber numberWithInt:highScoreInt] forKey:@"highscore"];
  [[NSUserDefaults standardUserDefaults] synchronize];

}

当您需要加载分数时，请在您要加载分数的任何方法中执行以下操作：

int highScore = [[NSUserDefaults standardUserDefaults] objectForKey:@"highscore"];

在阅读NSUserDefaults时，您会发现此link有用。

Answer 2

使用 NSInteger 而不是int

NSInteger highScore=0;

存储它

[[NSUserDefaults standardUserDefaults] setInteger:highScore forKey:@"HighScore"];

并将其取回

NSInteger highScore = [[NSUserDefaults standardUserDefaults] integerForKey:@"HighScore"];

Answer 3

我强烈建议每当更改时保存高分。

退出应用程序

3 个答案: