ios程序后台运行时，当有消息推送过来，如何修改程序角标上是数字？

当你使用本地推送的时候，自己知道消息数增加的位置，程序在后台是可以

UIApplication:setApplicationIconBadgeNumber函数,来设置脚标如果是远程的aps,例如Jpush,需要后台赋值badge,传给苹果服务器，实现自动加。当然，这种情况在你进入程序的时候，仍需

调用UIApplication:setApplicationIconBadgeNumber函数,来设置脚标。

  [[UIApplication sharedApplication] setApplicationIconBadgeNumber:99]

    [[UIApplication sharedApplication] setApplicationIconBadgeNumber:count]

  [UIApplication sharedApplication].applicationIconBadgeNumber = 99

  当角标个数为0的时候，设置个数为0，系统会自动设置角标不显示

如果项目中集成了友盟的推送，那就是友盟推送默认清空角标，需要将默认清空关闭。调用此方法：

[UMessage setBadgeClear:NO]

    UIUserNotificationSettings *settings = [UIUserNotificationSettings settingsForTypes:UIUserNotificationTypeBadge categories:nil]

    [[UIApplication sharedApplication] registerUserNotificationSettings:settings]

    [application registerForRemoteNotifications]

    if (@available(iOS 10.0, *)) {

        UNUserNotificationCenter *center = [UNUserNotificationCenter currentNotificationCenter]

        center.delegate = self

        [center requestAuthorizationWithOptions:(UNAuthorizationOptionBadge|UNAuthorizationOptionSound) completionHandler:^(BOOL granted, NSError * _Nullable error) {

            if (!error) {

                NSLog(@"请求权限成功!")

            }

        }]

        [center getNotificationSettingsWithCompletionHandler:^(UNNotificationSettings * _Nonnull settings) {

            NSLog(@"%@",settings)

        }]

        [[UIApplication sharedApplication] registerForRemoteNotifications]

    } else {

        // Fallback on earlier versions

    }

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