如何在Linux和Windows平台发布Qt/C++应用？术语解惑与步骤问询

Hey there! Let's break down all your questions about releasing and deploying your Qt C++ app step by step—this stuff can feel overwhelming at first, but it's totally manageable once you get the hang of it.

Let’s start with the terminology, since that’s often the first point of confusion:

• Releasing is the process of prepping your finished app for distribution. That means compiling it in release mode (not debug—debug builds have extra debugging symbols, run slower, and aren’t meant for end users), ensuring all dependencies are accounted for, and getting it into a self-contained state ready to hand off to users.
• Deploying is the next phase: getting that prepared app onto users’ machines, making sure it runs correctly there, and handling any setup they need (like installing missing libraries, creating shortcuts, or registering file types). So releasing is about building the "package," deploying is about making that package work on end-users’ systems.

You’ll want an installer when:

• Your app relies on multiple files (Qt libraries, assets, configs) that need to be placed in specific system locations.
• You want to add convenience features like start menu shortcuts, desktop icons, or file association support.
• You need to handle prerequisites (e.g., Visual C++ Redistributable on Windows, or Qt libraries on Linux if they aren’t pre-installed).

For Qt apps, here’s how to build installers:

• Windows: Use the Qt Installer Framework (QIF)—it’s purpose-built for Qt apps. You’ll create an XML configuration file that defines which files to include, shortcuts, and installation paths. Then run the binarycreator tool to generate the installer. If you prefer third-party tools, Inno Setup or NSIS are popular alternatives.
• Linux: For native distro support, package your app as a .deb (Debian/Ubuntu) or .rpm (Fedora/RHEL). Tools like dpkg-deb (for debs) or rpmbuild (for rpms) help create these packages. For universal distribution across most Linux distros, use Flatpak or Snap—both use manifest files to define dependencies and build steps.

Let’s walk through this clearly, since Windows deployment has a few moving parts:

1. Compile in Release Mode: Open your Qt Creator project, switch the build configuration from Debug to Release (look for this dropdown in the bottom-left corner of Qt Creator). Build the project—this will generate a release version of your .exe in the build directory.
2. Collect Dependencies: The raw .exe won’t run on a machine without Qt installed. Use Qt’s windeployqt tool to grab all required libraries:
   • Open the Qt Command Prompt that matches your Qt version and compiler (e.g., Qt 6.5 MSVC 2019 64-bit).
   • Navigate to the folder where your release .exe is stored.
   • Run: windeployqt --quick .\your-app-name.exe (the --quick flag skips optional files; remove it if you need all assets like translations).
   • This copies all necessary Qt DLLs, plugins, and resources into the same folder as your .exe.
3. Check Prerequisites: If you used MSVC to compile, users will need the matching Visual C++ Redistributable package. You can either include it in your installer or instruct users to download it from Microsoft.
4. Test on a Clean Machine: Copy the entire folder (.exe + dependencies) to a Windows machine without Qt installed. If it runs, you’re set.
5. Create an Installer (Optional but Recommended): Wrap the folder into a single installer using QIF, Inno Setup, or NSIS for easier distribution.

Linux has multiple distros, so here are the most common deployment paths:

• Native Packages (.deb/.rpm):
  • Debian/Ubuntu: Create a .deb package. You’ll need a DEBIAN directory with control files defining dependencies, version, and installation paths. Use dpkg-deb --build to generate the package.
  • Fedora/RHEL: Use rpmbuild to create an .rpm package. You’ll need a spec file outlining the build process, dependencies, and installation steps.
• Universal Packages (Flatpak/Snap):
  • Flatpak: Write a manifest file that specifies your app’s dependencies (including Qt), build steps, and runtime. Use flatpak-builder to build the package—users can install it via flatpak install across nearly all Linux distros.
  • Snap: Use Snapcraft to create a snapcraft.yaml file defining your app’s setup. Snapcraft handles building and packaging, and users install via snap install.
• Portable Tarball: For a simple, no-install option:
  • Compile your app in release mode.
  • Use ldd your-app-binary to list all shared library dependencies.
  • Copy the binary and all required libraries into a folder, then package it as a .tar.gz. Users can extract it and run the binary directly (note: they’ll need any system-level dependencies installed).

Pro tip: Use linuxdeployqt (similar to windeployqt for Windows) to automate collecting dependencies and creating a portable bundle or package structure for Linux.

内容的提问来源于stack exchange，提问作者Juliette Marquis