iOS app角标设置

设置app右上角的角标数字，设置为0，则不显示

//开启用户权限，否则不会显示
NSString * version = [UIDevice currentDevice].systemVersion;
    if ([version floatValue] >= 8.0) {
        UIUserNotificationSettings * set = [UIUserNotificationSettings settingsForTypes:UIUserNotificationTypeBadge categories:nil];
        [[UIApplication sharedApplication] registerUserNotificationSettings:set];
        [[UIApplication sharedApplication] registerForRemoteNotifications];
    }
//设置显示数字
[[UIApplication sharedApplication] setApplicationIconBadgeNumber:10];

该方法一般放在当app退到后台挂起时，所以应当放在app生命周期的方法中

- (void)applicationDidEnterBackground:(UIApplication *)application {
    
}