为x86构建的UWP应用是否可以在x64上运行？

Question

I'm having a problem, and found a suggestion to build for x86 only. But I'm not sure, though x86 can run on x64 computers, does that mean it will run as a UWP app as well, and be offered to x64 clients?

The docs weren't clear.

Answer 1

TL;DR: An x86 only UWP app will run on Windows x64 consumer systems, but won't run on Xbox One or older Windows ARM-based devices.

Generally speaking modern Windows x64 desktop PCs have the "Windows-on-Windows" layer which supports running 32-bit applications as well as 64-bit native apps for improved compatibility. That said, there are 64-bit versions of Windows that do not support running 32-bit apps like Windows Server (it's an optional feature) or Xbox One (which can only run x64 native apps). In these cases, a UWP package with only x86 would not run.

x86 and ARM has to date mostly been relevant to Windows Mobile platforms. There are some recently released Windows 10 on ARM devices entering the market that can run x86 or ARM, but not x64 applications.

x64 works on most Windows desktop PCs and Xbox One. Depending on the exact market segment you are targeting and your application type, you could go with just an x64 only architecture package--this is mostly relevant to high-end games or heavy performance applications.

Ideally you would ship your UWP app for all supported architectures including x86, x64 native, and ARM assuming you are able to actually test them all.

See Windows 64 , UWP on Xbox One , and DirectX and UWP on Xbox One

Answer 2

an x86 build will NOT run on 1) windows rt/Windows S 2) xbox. 3) any windows mobile variant.

it will run on 1) windows for desktop either natively or under the WOW architecture. both 32 and 64 bit versions. 2) windows 10 for ARM 64 bit os (via win32 emulation layer under WOW.) any device that has this OS will work. 3) Hololens (requires x86) 4) IOT Core, depending on your device. 5) Surface Hub (whatever that is)

By now you can also compile arm64, which only runs on windows 10 for ARM.