Building a Cross-Platform App with Xojo: My Experience

Posted on by Andy Timmins

As a keen developer always on the lookout for tools that genuinely make my life simpler, I recently took the plunge into Xojo for a personal cross-platform project. I was sceptical at first—could one environment really deliver a seamless experience across Windows, Mac, and mobile without turning my codebase into a maintenance nightmare? Spoiler: I was surprised—in the best way imaginable.

Why Xojo?

I’d tinkered with various cross-platform tools before, ranging from Electron (heavyweight and, at times, clunky) to some rather niche frameworks that never felt quite right for native experiences. Xojo drew me in with its promise of writing once and running anywhere—almost like magic, but with proper type safety and straightforward syntax somewhere between VB and real OOP languages like Swift or C#.

Getting Started: Fast and Frictionless

Setting up couldn’t have been easier. Xojo’s IDE is refreshingly minimalist (in a good way), with drag-and-drop UI design and an immediately accessible scripting area. My aim was to build a lightweight utility that needed both local network comms (UDP and TCP) and a shared codebase for desktop and mobile—on a tight timescale.

Quick Wins with Networking

One of my earliest wins was realising just how breezily Xojo handles networking. Enabling TCP and UDP functionality didn’t require hours wrestling with arcane libraries.

  • UDP: I hooked into the UDPSocket class to broadcast messages and receive responses. Here’s a snippet to set up a basic UDP listener within a window:

Dim sock As New UDPSocket
sock.Port = 12345
sock.Listen

  • TCP: For reliable two-way comms, TCPSocket proved equally straightforward. Sending and receiving data across platforms worked, well, instantly:

Dim sock As New TCPSocket
sock.Address = "192.168.1.100"
sock.Port = 6789
sock.Connect

The real surprise? I made only the smallest tweaks to get this running on Mac, Windows and even iOS—each platform’s quirks nicely abstracted away.

Cross-Platform UI Design

Part of my initial hesitation was rooted in UI consistency across devices. Xojo’s layout system allowed me to design once and, with judicious use of containers and platform-specific code branches, everything just felt native. For example, the same ListBox UI pasted into my Windows build was sharp and responsive on macOS and didn’t skip a beat on my iPhone test device.

  • Conditional Compilation: I took advantage of Xojo’s compilation directives to handle little platform quirks:

#If TargetWindows Then
' Windows-only tweaks
#ElseIf TargetMacOS Then
' macOS-specific code
#ElseIf TargetIOS Then
' iOS adjustments
#EndIf

Sharing Code: One Logic, Many Platforms

The real star was being able to spin core business logic into shared modules. For my app, parsing network payloads and handling serialisation were platform-agnostic—the same routines, unaltered, served in Windows, Mac, and mobile builds. That meant less duplication, fewer bugs, and a sense of real control over my codebase.

Packaging and Deployment: Painless

I’m always bracing myself for the dreaded packaging stage, especially with mobile. Xojo’s build settings made deploying to Windows executable, Mac .app, and iOS builds a cinch. Certificates aside (can’t escape Apple’s walls!), the process felt smooth and well-documented.

Tips and Lessons Learned

  1. Start with modules: Even for small projects, putting shared logic in modules keeps your platform-specific code neat and dry.
  2. Test early on all targets: Occasionally, a small difference does emerge—especially with fonts or UI sizing.
  3. Lean on Xojo’s community: The forums are surprisingly friendly and full of pragmatic advice—don’t reinvent the wheel if you get stuck.
  4. Don’t fear networking: The abstractions are robust and reliable; I found debugging and tracing packets extremely manageable.

Final Thoughts

All told, Xojo managed to exceed my expectations—speedy prototyping, reliable networking, and a real feeling that I was in control (not at the mercy of my tooling). For solo developers seeking a nimble, approachable route to genuine cross-platform apps without a massive learning curve, I can’t recommend it enough.

Have you tried Xojo for your own projects, or do you have questions about cross-platform development? I’d love to hear your experiences and tips—drop a comment below or share this post if you found it interesting!