原创 C语言可变参数函数使用总结

//ADS1.2下编译使用
void TestFun(char* fmt,...)
{
    int ch;
    char selch = 0;
    va_list ap = NULL;
    va_start(ap, fmt);
    do
    {
        selch = *fmt;
        if (selch!='%')
        {
            putchar(*fmt);
        }
        else
        {
            selch = *++fmt;
            switch(selch)
            {
            case 'c':
                    ch = va_arg(ap, int);
                    printf("%c",ch);
                    break;
            case 'd':
                    ch = va_arg(ap,int);
                    printf("%d",ch);
                    break;
            case 'x':
                    ch = va_arg(ap, int);
                    printf("%#x",ch);
                    break;
            }
        }

        ++fmt;

    }while(*fmt!='\0');

    va_end(ap);    
   }

  //调用
   TestFun((char*)"this is %d,%c,%x",1234,'6',0x12345);

//WIN-TC编译通过
   ＃i nclude    <stdarg.h>
/************************************************************
typedef void    *va_list;

#define va_start(ap, parmN)    (ap = ...)
#define va_arg(ap, type)    (*((type *)(ap))++)
#define va_end(ap)

********************************************************************/
void TestFun(cosnt char* fmt,...)
{
    int ch;
    long i32value = 0;
    char selch = 0;
    va_list ap = 0;
    va_start(ap, fmt);
    do
    {
        selch = *fmt;
        if (selch!='%')
        {
            putch(*fmt);
        }
        else
        {
            selch = *++fmt;
            switch(selch)
            {
            case 'c':
                    ch = va_arg(ap, int);
                    printf("%c",ch);
                    break;
            case 'd':
                    ch = va_arg(ap,int);
                    printf("%d",ch);
                    break;
            case 'x':
                    ch = va_arg(ap, int);
                    printf("%#x",ch);
                    break;
            case 'l':
                    if(*++fmt== 'd')
                    {
                        i32value = va_arg(ap, long);
                        printf("%ld",i32value);
                    }
                    else
                    {
                        putch('l');

                        if(*fmt!=0)
                        {
                            putch(*fmt);
                        }
                    }
                    break;
            default:
                    break;
            }
        }

        ++fmt;

    }while(*fmt!='\0');

    va_end(ap);   
}   
   
   void    main(void)  
   {
   TestFun("this is %d,%c,%x,%ld",1234,'6',0x2345,(long)12345678);
   getch();
   }

    
   void    main(void)  
   {
      TestFun("this is %d,%c,%x,%ld",1234,(char)'6',0x2345,(long)12345678);
   getch();
   }    

上述的example使用宏定义, var_start(ap, pareN),var_arg(ap,type),var_end(ap).

var_start(ap, pareN) //是ap指向第一个变参.

var_arg(ap,type),//返回变参的实际值.

var_end(ap).//是ap指向空指针.

具体的实现,在不同的编译环境下有所不同.