Desktop to UWP Bridge: Prepare

This article lists things you need to know before converting your app with the Desktop to UWP Bridge. You may not need to do much to get your app ready for the conversion process, but if any of the items below applies to your application, you need to address it before conversion. Remember that the Windows Store handles licensing and automatic updating for you, so you can remove those features from your codebase.

  • Your app uses a version of .NET earlier than 4.6.1. Only .NET 4.6.1 is supported. You must retarget your app to .NET 4.6.1 before converting.

  • Your app always runs with elevated security privileges. Your app needs to work while running as the interactive user. Users who install your app from the Windows Store may not be system administrators, so requiring your app to run elevated means that it won't run correctly for standard users.

  • Your app requires a kernel-mode driver or a Windows service. The bridge is suitable for an app, but it does not support a kernel-mode driver or a Windows service that needs to run under a system account. Instead of a Windows service, use a background task.

  • __Your app's modules are loaded in-process to processes that are not in your Windows app package. This isn't permitted, which means that in-process extensions, like shell extensions, aren't supported. But if you have two apps in the same package, you can do inter-process communication between them.

  • Your app calls SetDllDirectory or AddDllDirectory. These functions are not currently supported for converted apps. We are working on adding support in a future release. As a workaround, you can copy any .dlls you were locating using these functions to your package root.

  • Your app uses a custom Application User Model ID (AUMID). If your process calls SetCurrentProcessExplicitAppUserModelID to set its own AUMID, then it may only use the AUMID generated for it by the app model environment/Windows app package. You can't define custom AUMIDs.

  • Your app modifies the HKEY_LOCAL_MACHINE (HKLM) registry hive. Any attempt by your app to create an HKLM key, or to open one for modification, will result in an access-denied failure. Remember that your app has its own private virtualized view of the registry, so the notion of a user- and machine-wide registry hive (which is what HKLM is) does not apply. You will need to find another way of achieving what you were using HKLM for, like writing to HKEY_CURRENT_USER (HKCU) instead.

  • Your app uses a ddeexec registry subkey as a means of launching another app. Instead, use one of the DelegateExecute verb handlers as configured by the various Activatable* extensions in your app package manifest.

  • Your app writes to the AppData folder with the intention of sharing data with another app. After conversion, AppData is redirected to the local app data store, which is a private store for each UWP app. Use a different means of inter-process data sharing. For more info, see Store and retrieve settings and other app data.

  • Your app writes to the install directory for your app. For example, your app writes to a log file that you put in the same directory as your exe. This isn't supported, so you'll need to find another location, like the local app data store.

  • Your app installation requires user interaction. Your app installer must be able to run silently, and it must install all of its prerequisites that aren't on by default on a clean OS image.

  • Your app uses the Current Working Directory. At runtime, your converted app won't get the same Working Directory that you previously specified in your desktop .LNK shortcut. You need to change your CWD at runtime if having the correct directory is important for your app to function correctly.

  • Your app requires UIAccess. If your application specifies UIAccess=true in the requestedExecutionLevel element of the UAC manifest, conversion to UWP isn't supported currently. For more info, see UI Automation Security Overview.

  • Your app exposes COM objects or GAC assemblies for use by other processes. In the current release, your app cannot expose COM objects or GAC assemblies for use by processes originating from executables external to your Windows app package. Processes from within the package can register and use COM objects and GAC assemblies as normal, but they will not be visible externally. This means interop scenarios like OLE will not function if invoked by external processes.

  • Your app is linking C runtime libraries (CRT) in an unsupported manner. The Microsoft C/C++ runtime library provides routines for programming for the Microsoft Windows operating system. These routines automate many common programming tasks that are not provided by the C and C++ languages. If your app utilizes C/C++ runtime library, you need to ensure it is linked in a supported manner.

    Visual Studio 2015 supports both dynamic linking, to let your code use common DLL files, or static linking, to link the library directly into your code, to the current version of the CRT. If possible, we recommend your app use dynamic linking with VS 2015.

    Support in previous versions of Visual Studio varies. See the following table for details:

    Visual Studio versionDynamic linkingStatic linking
    2005 (VC 8)Not supportedSupported
    2008 (VC 9)Not supportedSupported
    2010 (VC 10)SupportedSupported
    2012 (VC 11)SupportedNot supported
    2013 (VC 12)SupportedNot supported
    2015 (VC 14)SupportedSupported

    Note: In all cases, you must link to the latest publically available CRT.

  • Your app installs and loads assemblies from the Windows side-by-side folder. For example, your app uses C runtime libraries VC8 or VC9 and is dynamically linking them from Windows side-by-side folder, meaning your code is using the common DLL files from a shared folder. This is not supported. You will need to statically link them by linking to the redistributable library files directly into your code.

  • Your app uses a dependency in the System32/SysWOW64 folder. To get these DLLs to work, you must include them in the virtual file system portion of your Windows app package. This ensures that the app behaves as if the DLLs were installed in the System32/SysWOW64 folder. In the root of the package, create a folder called VFS. Inside that folder create a SystemX64 and SystemX86 folder. Then, place the 32-bit version of your DLL in the SystemX86 folder, and place the 64-bit version in the SystemX64 folder.

  • Your app uses the Dev11 VCLibs framework package. The VCLibs 11 libraries can be directly installed from the Windows Store if they are defined as a dependency in the Windows app package. To do this, make the following change to your app package manifest: Under the <Dependencies> node, add:
    <PackageDependency Name="Microsoft.VCLibs.110.00.UWPDesktop" MinVersion="11.0.24217.0" Publisher="CN=Microsoft Corporation, O=Microsoft Corporation, L=Redmond, S=Washington, C=US" />
    During installation from the Windows Store, the appropriate version (x86 or x64) of the VCLibs 11 framework will get installed prior to the installation of the app.
    The dependencies will not get installed if the app is installed by sideloading. To install the dependencies manually on your machine, you must download and install the VC 11.0 framework packages for Desktop Bridge. For more information on these scenarios, see Using Visual C++ Runtime in Centennial project.

  • Your app contains a custom jump list. There are several issues and caveats to aware of when using jump lists.

    • Your app's architecture does not match the OS. Jump lists currently do not function correctly if the app and OS architectures do not match (e.g., an x86 app running on x64 Windows). At this time, there is no workaround other than to recompile your app to the matching architecture.

    • Your app creates jump list entries and calls ICustomDestinationList::SetAppID or SetCurrentProcessExplicitAppUserModelID. Do not programmatically set your AppID in code. Doing so will cause your jump list entries to not appear. If your app needs a custom Id, specify it using the manifest file. Refer to Manually convert your app to UWP using the Desktop Bridge for instructions. The AppID for your application is specified in the YOUR_PRAID_HERE section.

    • Your app adds a jump list shell link that references an executable in your package. You cannot directly launch executables in your package from a jump list (with the exception of the absolute path of an app’s own .exe). Instead, register an app execution alias (which allows your converted app to start via a keyword as though it were on the PATH) and set the link target path to the alias instead. For details on how to use the appExecutionAlias extension, see Desktop Bridge app extensions. Note that if you require assets of the link in jump list to match the original .exe, you will need to set assets such as the icon using SetIconLocation and the display name with PKEY_Title like you would for other custom entries.

    • Your app adds a jump list entries that references assets in the app's package by absolute paths. The installation path of an app may change when its packages are updated, changing the location of assets (such as icons, documents, executable, and so on). If jump list entries reference such assets by absolute paths, then the app should refresh its jump list periodically (such as on app launch) to ensure paths resolve correctly. Alternatively, use the UWP Windows.UI.StartScreen.JumpList APIs instead, which allow you to reference string and image assets using the package-relative ms-resource URI scheme (which is also language, DPI, and high contrast aware).