CODEWITHSUNDEEP
c#windows-phone-8win-universal-app
Tank Zhang
Tank Zhang

Reputation: 41

my roaming data dosen't sync between devices

I made a UWP application. I use the roamingdata.I save the setting by this:

public static void WriteCode(string pwd)
{
   ApplicationDataContainer RoamingSettings = ApplicationData.Current.RoamingSettings;
   RoamingSettings.Values["Code"] = EncryptHelper.PwdEncrypt(pwd);
}

I read the setting by this:

 public static string GetCode()
    {
        ApplicationDataContainer RoamingSettings = ApplicationData.Current.RoamingSettings;
        string str = (String)RoamingSettings.Values["Code"];
        if (!String.IsNullOrEmpty(str))
            return str;
        else
            return EncryptHelper.PwdEncrypt("123");
    }

I complete the application and upload to windows store and passed check. Then I download this app on my phone.

I change the ApplicationData.Current.RoamingSettings on phone. I write something to the ApplicationData.Current.RoamingFolder on my phone.

Next I closed the app on my phone and download the app on my PC. But when I opened the app on my PC, I found that the ApplicationData.Current.RoamingSettings and the ApplicationData.Current.RoamingFolder didn't change anything.

I checked the C:\Users\XXX\AppData\Local\Packages\XXX\RoamingState on my PC,there was nothing. I checked C:\Users\XXX\AppData\Local\Packages\XX\Settings on my PC,there was roaming.lock and settings.dat. But I can't read the lastest settings and roaming data that I haved added on my phone anymore.

I have waited for 2 hours, there was no change on my PC.

there is something that I should state first:

   1 All the deploy work was done by windows store.

   2 I check my PC application setting after closed the app on phone. I even shut down my mobile phone to observe the change to my PC.

what's wrong with my code? or what's wrong with the roamingdata mechanism? I need an answer, thank you!

Upvotes: 4

Views: 1008

Answers (1)

Jay Zuo
Jay Zuo

Reputation: 15758

The code you've posted is right. However, there are some possible reasons for the failure of roaming data sync:

  1. Any user can benefit from roaming app data if they use a Microsoft account to log on to their device. However, users and group policy administrators can switch off roaming app data on a device at any time. If a user chooses not to use a Microsoft account or disables roaming data capabilities, she will still be able to use your app, but app data be local to each device.

    Keep in mind that roaming data is associated with a user's Microsoft account. Roaming data will only sync if a user logs into her devices using the same Microsoft account and installs the app on several devices.

  2. Don't use roaming for data that relies on instant syncing. Windows doesn't guarantee an instant sync; roaming could be significantly delayed if a user is offline or on a high latency network.

    Roaming of settings is not instant. The system weighs several factors when determining when to send the data. We can detect whether new roaming data has arrived on the local device by listening for the ApplicationData.DataChanged event. This event occurs when app data has just finished syncing from the cloud. Any time a device receives new roaming data, the DataChanged event will fire, passing in the updated ApplicationData object. This lets us make any adjustments to our app when data has changed.

    For important, time critical settings, use the HighPriority setting associated with RoamingSettings like following:

    // High Priority setting, for example, last page position in book reader app
roamingSettings.values["HighPriority"] = "65";

    This is a special key in the roaming settings we can use for data we need to sync immediately. Adding HighPriority to any setting will have it synced as quickly as possible.

  3. Don't roam large sets of app data. There's a limit to the amount of app data an app may roam; use RoamingStorageQuota property to get this maximum. If an app hits this limit, no data can roam until the size of the app data store no longer exceeds the limit.

    The name of each setting can be 255 characters in length at most. Each setting can be up to 8K bytes in size and each composite setting can be up to 64K bytes in size. The sync engine may limit the total size of settings and files that can roam. It’s important to keep track of the amount of data you’re attempting to roam. If the total amount of data you’re attempting to sync exceeds the limit, then nothing will sync between the devices.

  4. App data only roams between installed apps with the same version number. For example, devices on version 2 will transition data between each other and devices on version 3 will do the same, but no roaming will occur between a device running version 2 and a device running version 3. If you install a new app that utilized various version numbers on other devices, the newly installed app will sync the app data associated with the highest version number.

    If you are using versioning in your roaming date, please make sure you are dealing with the right version.

These are some possible reasons that can cause roaming data doesn't sync between devices. For more info, please check Roaming data in Store and retrieve settings and other app data.

Upvotes: 2

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