Question

VC++ 定义了加、减、乘、除的消息函数，为什么乘号和除号不能使用呢？

void CCalculator1Dlg::OnDivision()
{
// TODO: Add your control notification handler code here
UpdateData(TRUE);
m_result=m_num1/m_num2;
UpdateData(FALSE);
}

void CCalculator1Dlg::OnMinus()
{
// TODO: Add your control notification handler code here
UpdateData(TRUE);
m_result=m_num1-m_num2;
UpdateData(FALSE);
}

void CCalculator1Dlg::OnMultiplication()
{
// TODO: Add your control notification handler code here
UpdateData(TRUE);
m_result=m_num1*m_num2;
UpdateData(FALSE);
}

void CCalculator1Dlg::OnPlus()
{
// TODO: Add your control notification handler code here
UpdateData(TRUE);
m_result=m_num1+m_num2;
UpdateData(FALSE);
}

编译有错误，如下：
D:\vcproject\calculator1\calculator1Dlg.cpp(184) : error C2676: binary '/' : 'class CString' does not define this operator or a conversion to a type acceptable to the predefined operator
D:\vcproject\calculator1\calculator1Dlg.cpp(200) : error C2676: binary '*' : 'class CString' does not define this operator or a conversion to a type acceptable to the predefined operator
执行 cl.exe 时出错.

calculator1.exe - 1 error(s), 0 warning(s)

Answer 1

你的m_num1 m_num2都是CString字符串吗？如果是的话请先转换成数值类型（int、double……）再进行运算

追问

如何转换啊，请教一下

追答

转换成整数的话：
int i=_ttoi(m_num1);

浮点的话：
double f=_ttof(m_num1);