#include<stdio.h>
#include<string.h>

int main()
{
    char *string = "1266,400";
    char *p = strtok(string, ",");
    printf("%s\n", strtok(string, ","));
    p = strtok(NULL, ",");
    printf("%s\n", p);

    return 0;
}

你都没有定义strtok函数的第二个参数