Hi Ehsan,
I would like to add some comments, beside Jan's very detailed explanations.
I am a Microstation programmer and use several languages. It depends on the goal you want to achive.
1) C++ is good for large projects, BUT you have to compile your program with the same SDK version as the target Microstation version. To Compile the program you will need Visual Studio 2007.
2) MDL/Ansi C. Thats the language the most existing programs are made of. If you do migrating of older programs you will have to deal with that language. Also the user base (in this community for example) is much larger than for C++ programs. There is an compiler and make program included in the SDK, but the so called bmake is a nightmare, even for experienced programmers.
3) VBA/MVBA: Not so bad, as always said.
- Robust, you will not have to recompile your program for a "newer" version of Microstation.
- IDE is included and easy to use.
- You can make use of any function in a mdl library.
- By far the largest communitiy.
- Recommended by Bentley for "simple" tasks.
- But of course it cant compare with C++ when you create large projects.
To your questions.
1) Not possible. You have to use Visual Studio 2007.
2) The functions are comparable, but you have to redesign manually. There are no code converters available.
3) You can download both Microstation and SDK from the Bentley Website. If you want to get a programmers license for Microstation you have to apply for a special BDN license.
4) I would suggest to look at some examples. Some are provided when you download the SDK.
Regards and Khoda hafez, Stefan.