ArcGIS Runtime SDK for .NET (Windows Phone) - ArcGISLocalTiledLayer Issue

Question

I'm developing Windows Phone 8.1 client for our company ArcGIS maps. Online layers works fine, but I need to deliver offline maps (Map Tile Package - .tpk file) to users with bad connectivity. My problem is that not every user has device with Storage Card, and I try to save .tpk file to Internal Storage of Phone, i.e. Pictures Library folder. I can succesfully read .tpk file from there to StorageFile, so the app has the permission to read, but I cannot initialize ArcGISLocalTiledLayer from this file. Even when I copy file to App Local Store, still cannot initialize ArcGISLocalTiledLayer from this file. I tried different path formats: // Settings.LocalDataPath = "C:\Data\Users\Public\Pictures\Camera Roll\ArcGIS\MS_PM_BaseMap.tpk"; - when loading from Pictures Library // Settings.LocalDataPath = "ms-appdata:///local/MS_PM_BaseMap.tpk"; - when file is in Local Storage // Settings.LocalDataPath = "isostore:/MS_PM_BaseMap.tpk"; - another try... var tpk = new ArcGISLocalTiledLayer(Settings.LocalDataPath); tpk.ID = "tpk"; await tpk.InitializeAsync(); on InitializeAsync() I get exception "Failed to open file. May not be a valid tile package.". When file is saved on StorageCard, initialization works fine. Is it possible to use .tpk file from any location in phone's internal storage?

SomeGISGuy · Answer

There's only two valid root locations for TPK files to be readable in a phone app: Local and App data. Ie ms-appdata:///... and ms-appx:///...

That you can read a file using the StorageFile APIs unfortunately doesn't confirm whether it's usable, as we require direct native read of the file to be able to use them at this point. We are aware this isn't ideal, but it's unfortunately a platform limitation at this point. I would however encourage you to vote for this issue to improve this in the future:

https://wpdev.uservoice.com/forums/253374-missing-platform-apis/suggestions/6039773-improve-storagefile-use-from-c-cross-platform-co

AndrejMelicher · Answer

Hi, another complication, don't know if need to create a new thread, maybe placing the question here would be fine.

As I wrote before, I successfully use TPK file stored in SD card when testing release build locally. But now I publish the package to Store and again I get exception "Failed to open file. May not be a valid tile package." even when TPK file is located on SD card. Some kind of strange security issue when package is published on Store?

AndrejMelicher · Answer

Hi, sorry for delay, I was offline during weekend.

In WP, you don't have many options where to store custom data when your device don't support SD card. The Documents folder is inaccesible for 3rd party apps, then you have Pictures, Music and Video Library... Nothing else.

In my scenario, end users are foresters with very limited connectivity on phones, and little better connectivity on their PCs in offices. So the best option for them is to copy files from PCs to phones via USB cable, and as I wrote before, there are different map packages then need to have on devices and switch them on demand.

In conclusion, I'm going to use "copy to application data storage" scenario, but maybe in future, it would be nice if ArcGIS SDK supports locations like Pictures Library to store .tpk files.