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Visual C++ Localization and Internationalization
Visual C++ (Wikipedia) is a popular Windows development IDE. Soluling localization tool and service support Visual C++.
The following chapters describe Visual C++ localization step by step.
You can localize Visual C++ applications using the following methods:
The first way to localize a Visual C++ project is to add an executable file into a Soluling project. Soluling reads the file to locate all the resource data it contains. When building, Soluling creates localized executable files. There is one output file for each language. You don't need to have the source code files. The only file you need is the original executable file.
Another localization method is to localize each resource file (.rc). Soluling reads the file to locate all the resource data it contains. When building, Soluling creates localized resource files. There is one output file for each language.
Visual C++ applications use the standard Windows resources. They are defined in one or more .rc files. There are several resource types such as string, menu, and dialog resources. When Visual Studio compiles your application is also compiles the .rc files into the .res files. .res file is the binary version of the .rc file. The .res files are then linked into the final output file: portable executable.
Windows (Wikipedia) application is a file that has an EXE file extension. In addition to an EXE file, it can contain any number of dynamic library files (.DLL). The format of EXE and DLL files is the same Windows Portable Executable, PE, (Wikipedia). A PE file contains compiled code and resources. You can not change the compiled code after it has been compiled from the source code, but it is possible to change the resource data. Soluling's Windows localization is based on changing of resource data inside the PE file. Similar file formats are ELF that is used in Linux, and Mach-O that is used in OS X and iOS.
The following picture shows the structure of a PE file. It contains two segments: compiled code segment and resource segment. The resources are in English.
If we want to localize this application into German, we need to replace the English resources with German ones.
The important thing here is that the code segment is exactly the same as in the original English PE file. Only the resource segment has been modified. It contains the same resource items as the original file, but each item contains German data (e.g., German text). In the same way, if we want to localize the application into French, we need to replace the resources with French ones.
In the above sample, we copied the original PE file and replaced the resources inside the PE file. This is the simplest way to localize Windows applications. The only thing you have to do is to properly internationalize your application. If you have already done it, you don't have to change your source code. You don't even have to recompile your application. This method is the default localization method of Windows application in Soluling.
There is another way to localize Windows applications. Instead of coping the PE file itself, we can copy only the resource data and store it inside a resource DLL. It is a special DLL that contains no code but only resource data. Resource DLLs are used to store localized resources. You can not run a resource DLL, but it is always used by the original PE file (exe or dll).
The format of the DLL is still a Windows PE file, but it contains only resource data. It can not be started, but the application can load and use its resources instead of the resources of the application file.
If you deploy the original application (e.g., C:\Sample\Application.exe) and the German resource DLL (e.g., C:\Sample\Application.DEU), the application has two choices where to load the resources: either from the application file itself or from German resource DLL. What choice to use depends on the application, framework, and the operating system where you run the application. In most cases, the framework you use (e.g., MFC or VCL) automatically looks for a resource DLL matching the system locale of the computer. However, you can add your own code that makes the decision of what resource DLL to load. Soluling comes with lots of code to access resources and even perform runtime language switches.
The following sample contains the original application file and three resource DLLs. This makes it possible to start the same application either in English, German, French, or Japanese.
By using resource DLLs, you can save disk space, and what is more important the application can choose the initial language it uses when it starts.
If your application is written in Delphi and you have added Soluling's NtTranslator unit into your application, the above application can start in any above language, and the user can change the language on run time.
MFC adds MFC-specific resource types such as RibbonBar.
If you use MFC, you can take use MFC's automatic resource DLL loading.
MFC attempts to load the resource DLL for each of the following languages in order, stopping when it finds one:
If MFC does not find any satellite DLLs, it uses whatever resources are contained in the application itself.
There are several development tools for Windows. Most important are:
|Compiler||Description||Resources||Is compiler supported|
|Microsoft's C/C++ development tool.||Standard Windows resources and
optionally MFC resources
|Delphi||Embarcadero's Pascal-based RAD development tool.||Standard Windows resources and
VCL form resources
|Fully supported from Delphi version 7.
Delphi 2-6: Not officially supported but can be used to localize most applications written in these older 32-bit Delphi.
|C++Builder||As Delphi but uses C++ as programming languages instead of Pascal,||Standard Windows resources and
VCL form resources
|Not officially supported, but because C++Builder uses the same resource format as Delphi, most C++Builder applications can be localized.|