C # Learning notes: Preprocessing directives

C # and C + +, as well as preprocessing directives, let's look at preprocessing directives in C #.

#region

Code folding function, with #endregion use, as follows:

Click below:

Conditional preprocessing

Conditional preprocessing can determine the final compiled code based on the conditions given, in other words, you can exclude the specified code from compiling.

#define

Define a macro, and note that if you define a name, you do not need a value.

The macro definition is generally written in the first line.

#define IOS

This means that the macro for iOS is defined.

#undef

Cancel a macro definition, as follows:

#undef IOS

This will cancel the macro definition of iOS.

#if, #else, #elif, #endif

For specific instructions, show examples below:

1 #define ANDROID 2 #define iOS 3 #undef iOS 4  5 using System; 6  7 namespace Study 8 {9     class PROGRAM10     { One         by one static void Main (string[] args)         {#if ANDROID15             Console.WriteLine ("The Code of the Android platform is written here. "); #elif IOS17             Console.WriteLine (" IOS platform code is written here. "); #else19             Console.WriteLine (" The Code for the other platforms is written here. "); #endif21             console.read ();         }24     }25}

In unity, the corresponding macros have been defined for the corresponding platforms and versions, and the following links can be viewed:

Http://docs.unity3d.com/Manual/PlatformDependentCompilation.html

#warning, #error

These two instructions allow the editor to make warnings and errors, with general and conditional directives for debugging.

1 #warning shouldn't write like this here! 2 #error It's wrong to write like this here!

#line

With #warning and #error, you can set the exact number of lines for an error or warning.

1//200 Line problem 2 #line 200 "optional file name, indicating the specific problem file, without the suffix name. "3//recovery rows are the current number of rows 4 #line default

#pragma

This instruction can be extended by ourselves to complete specific functions, here is not much to say, to everyone a link to the article:

http://blog.csdn.net/jx_kingwei/article/details/367312

C # Learning notes: Preprocessing directives