How can I individually compile specified code segments in Qt?

In Qt, you can use conditional compilation directives #if and #endif to separately compile specific code segments. By adding conditional compilation directives before the code segment, you can control whether the compiler compiles that code segment. Here is an example:

#include <iostream>

#define ENABLE_CODE  // 定义一个宏，用于控制编译

int main()
{
    std::cout << "这段代码总是会被编译" << std::endl;

#ifdef ENABLE_CODE
    std::cout << "这段代码只有在宏 ENABLE_CODE 被定义时才会被编译" << std::endl;
#endif

    std::cout << "这段代码总是会被编译" << std::endl;

    return 0;
}

In the example above, the macro #define ENABLE_CODE is used to control compilation. The code block will only be compiled if the condition #ifdef ENABLE_CODE is true. Otherwise, the compiler will ignore that code block.

In practical applications, different macros can be defined as needed to control the compilation of code segments. This allows for compiling different code based on different conditions, achieving more flexible control and configuration.