编写跨平台程序

Question

How could I write a program which runs on both Windows 7, Mac OS X (and maybe linux too)?

I heard Qt are a great framework to build cross-platform GUIs, but I think every program version need a recompile, isn't that right? And should I compile the win version under windows, the mac version under mac os x, the linux version under linux and so on?

I'm getting ideas and/or suggestions

Answer 1

The underlying binary format is different on each platform, so unless you're using a virtual machine (like Java or Flash does) you will have to recompile your program on each platform.

Some compilers (like GCC) allow cross-compiling, but it is not trivial to set up. Probably the easiest system to cross-compile on is Linux (there are several open source projects that have cross compilation set up from Linux to Windows).

In case of a GUI application, it depends on the language -- if you're stuck with C++, Qt or wxWindows might be a reasonable choice providing an abstraction layer over the native windowing system.

If you can go with Java, it makes life simpler, however the windowing system is Java's and not native.

Another language to think about is FreePascal w/ Lazarus -- it has a pretty good GUI designer that compiles to the native windowing system on every platform (WinAPI on Windows, Cocoa on OSX and GTK on Linux).

Answer 2

Not sure if C++ is a must, but Adobe Air is a great cross platform development environment for desktop, and its growing for mobile development as well. If you need an example of a major application using Adobe Air to deploy to multiple desktop OSes, just check out tweetdeck http://www.tweetdeck.com/

I'd highly suggest also looking into Flex and Flash Builder if you go that route.

Answer 3

There are two separate issues I would highlight when writing cross-platform programs -- how to make your code portable, and how to arrange for it to be built on the various different platforms.

As far as the building side of things goes, I would look into a cross-platform build system like CMake ( http://www.cmake.org ). You essentially write a script and CMake will generate the appropriate project file/makefile for a specific platform. You then build your program on each platform as you would normally. For example, on Windows, you might use CMake to generate a Visual C++ project for you, and then use Visual C++ to actually build your executable. On Linux, you might use CMake to generate a makefile, and then build the executable using g++.

The other aspect is how to make your code portable -- the key is to write C++ standard-compliant code and make use of libraries that are themselves portable across the platforms you're interested in. You can (and may sometimes need to) write platform-specific code for each of the different platforms -- if you do, you should hide it behind a portable interface and have the rest of the code use that.

Answer 4

Yes, you need to compile for each version when using C++.

The only thing that prevents you from compiling a program, for example, for Windows on Mac is to get a tool for doing that. It is possible, but the problem is finding the toolset.

Also you can use a virtual machine for running diferent OSs and compiling code for all platforms on the same machine.

Answer 5

Java在Windows，OS X和Linux上运行