GOC按钮点击器

复习：

        

int main() 
{   
    int a,b;
    cin>>a>>b;
    pen.button(1,"加法计算",02,40,0,0,150,5);
    pen.button(2,"减法计算",10,40,90,-200,0,4);
    for (;;){
       if ( buttonMP(1))pen.text(a+b,0,32);
       if ( buttonMI(2))pen.text(a-b,0,32);
       pen.up().rt(1).hide();
}
     return 0;
}