我先是建好对话框，拉了一个编辑框上去。然后插入类shiyanshiyan，然后派生了一个类
class shiyanshiyan2:public shiyanshiyan
{
protected:
CString a;
public:
shiyanshiyan2(CString A)
{
a=A;
}
CString shiyanshiyan2_jieguo()
{
return a;
}
};
最后在Dlg.cpp上加上了类的头文件。把响应函数OnOk改为
void CMy2Dlg::OnOK()
{
// TODO: Add extra validation here
shiyanshiyan2 sth(1);
CString sth1;
sth1 = sth.shiyanshiyan2_jieguo();
SetDlgItemText(IDC_EDIT1,sth1);
}
然后运行，显示错误
error C2065: *shiyanshiyan2* : undeclared identifier
正确做法该怎样？