How can I enable my desktop applications built on Win32 or .NET (WPF/Winforms) to become a ShareTarget on Windows 10, so other apps can share content to it? Is this possible?
Yes, with the Anniversary Update for Win10 it is now possible for all desktop apps, thanks to the Desktop Bridge platform.
Do enable that feature, add the 'windows.ShareTarget' extension to your appxmanifest, and add a UWP component to the app package to provide the sharing UX when a user invokes a sharing operation for your app.
Related blog post (see the third example in the article): https://blogs.windows.com/buildingapps/2017/02/01/adding-uwp-features-existing-pc-software
Sample app on GitHub: https://github.com/Microsoft/DesktopBridgeToUWP-Samples/tree/master/Samples/WPFasShareTarget
Sample app in the Store: https://www.microsoft.com/en-us/store/p/wpf-app-as-sharetarget/9pjcjljlck37
Thanks,
Stefan Wick - Windows Developer Platform