UIApplication的作用:

UIApplication的作用:

  1.在应用程序图标上面添加数字

       1)获取UIApplication单例

           UIApplication *app = [UIApplication sharedApplication];

       2)注册通知

           UIUserNotificationSettings *setting = [UIUserNotificationSettings settingsForTypes:UIUserNotificationTypeBadge categories:nil];

           [app registerUserNotificationSettings:setting];

      3)设置应用程序图标提醒数字

           app.applicationIconBadgeNumber = 10;

2.设置连网状态

     //获取应用程序UIApplication单例

    UIApplication *app =[UIApplication sharedApplication];

     //网络工作活动表示可见

    app.networkActivityIndicatorVisible = YES;

3.打开URL

    UIApplication *app = [UIApplication sharedApplication];

    NSURL *url = [NSURL URLWithString:@"http://192.168.21.33:81"];

    [app openURL:url];

4.设置状态栏

UIApplication的作用:

原文：http://www.cnblogs.com/sanvow/p/5428274.html