文件系统WP7

Question

I want to save a text file on the wp7 file system that doesn't get deleted on uninstall of the app.

I want to save the version of the app and language preference selected by the user so that it doesnt get deleted when the user upgrades the app. I dont want to use IsolatedStorage instead i want to use the device's file system.. Is this possible? If yes how??? As of now am doing this:-

 public void SaveLanguageAndVersion()
    {
        IsolatedStorageFile appInfoFile = IsolatedStorageFile.GetUserStoreForApplication();

        //create new file
        using (StreamWriter writetoAppInfo = new StreamWriter(new IsolatedStorageFileStream("appInfo.txt", FileMode.Create, FileAccess.Write, appInfoFile)))
        {
            string appVer = new StringBuilder().Append(Utils.getRelVersion()).Append(":").Append(Utils.getFWversion()).ToString();
            writetoAppInfo.WriteLine(appVer);
            string appLanguage = CacheManager.getInstance().getApplicationSettings(Utils.APP_LANG);
            writetoAppInfo.WriteLine(appLanguage);
            writetoAppInfo.Close();
        }
    }

but the appinfo.txt file gets deleted on uninstalling of the app. I wanna overcome this.

If i use LINQ SQL can i overcome this problem and achieve what i want? ie, Save the app level info like the version and the language of user's choice?

Answer 1

This is not possible. If you want to have device / user specific data, consider using ANID or Device ID and store it in the Cloud

have a look at this post. Gives you info on how to get ANID and DeviceID http://www.nickharris.net/2010/09/windows-phone-7-how-to-find-the-device-unique-id-windows-live-anonymous-id-and-manufacturer/

Answer 2

Windows Phone 7 is quite picky about letting the user make changes outside of the applications isolated storage.

What you could do is save the preferences in the cloud and use either the device id or the user id as a key. And when the user reinstalls the app the preferences could be downloaded.