判断是否新版本

- (BOOL)application:(UIApplication *)application didFinishLaunchingWithOptions:(NSDictionary *)launchOptions

{

    self.window = [[UIWindowalloc] initWithFrame:[[UIScreenmainScreen] bounds]];

    

    NSString *key=(NSString*)kCFBundleVersionKey;

    

   //获取产品的版本号

    NSString *version=[[NSBundlemainBundle].infoDictionaryobjectForKey:key];

    

   //从沙盒中读取上次保存的的版本号

    NSString *saveVersion=[[NSUserDefaultsstandardUserDefaults]objectForKey:key];

   if ([version isEqualToString:saveVersion])

    {

       NSLog(@"不是新版本");

    }

   else

    {

        //是新版本，存入沙盒

        NSUserDefaults *defaluts=[NSUserDefaultsstandardUserDefaults];

        [defalutssetObject:version forKey:key];

        [defalutssynchronize];

        

       NSLog(@"是新版本");

    }

    

    self.window.backgroundColor = [UIColor whiteColor];

    [self.windowmakeKeyAndVisible];

    returnYES;

}