Question

In C++ we can use #ifdef to eliminate some debug statements when we release. C# is different from C++ in preprocessor. Can I still get the same result useing C# #if. We want to eliminate ALL debug statements by change one place and we have several different types of debug statements. Can have one file which contains ALL our #ifdef flags to turn on or turn off those debug statements? thanks

Answer 1

The according the MSDN docs

The scope of a symbol created by using #define is the file in which it was defined.

So you can’t have a file that defines several other defines that are used throughout your program. The easiest way to do this would be to have different configurations on your project file and specifying the list of defines for each configuration on the command line to the compiler.

Update:
You can set your project defines in Visual Studio by right-clicking on your project and selecting Properties. Then select the Build tab. Under general you can specify the defines to be sent to the compiler under “Conditional compilation symbols”. You can define different project settings using the Configuration Manager (Build->Configuration Manager)

Update 2:
When the “Conditional compilation symbols” are specified, Visual Studio emits a /define on the command line for the compiler (csc.exe for C#), you can see this by examining the output window when building your project. From the MSDN docs for csc.exe

The /define option has the same effect
as using a #define preprocessor
directive except that the compiler
option is in effect for all files in
the project. A symbol remains defined
in a source file until an #undef
directive in the source file removes
the definition. When you use the
/define option, an #undef directive in
one file has no effect on other source
code files in the project.

You can use symbols created by this
option with #if, #else, #elif, and
#endif to compile source files conditionally.