vc为什么我不能定义Cstring

void CDemo1Dlg::OnOK()
{
// TODO: Add extra validation here
UpdateData(TRUE);//获取数据A

cstring strB;//获取数据B

int nLen=m_ctlNumB.GetWindowTextLength();//获取字符串长度
if(nLen <=0)
{
AfxMessageBox(_T("请输入数字B！"));
return;
}

m_ctlNumB.GetWindowText(strB);
int iB;
iB=atoi(strB);

int n=m_iNumA iB;

Cstring strMsg;
strMsg.Format(_T("[%d]和[%d]的和为：[%d]!"),m_iNumA,iB,n);
AfxMessageBox(strMsg);
}

错误报告：

Compiling...
demo1Dlg.cpp
F:\[C ]\demo1\demo1Dlg.cpp(178) : error C2065: 'cstring' : undeclared identifier
F:\[C ]\demo1\demo1Dlg.cpp(178) : error C2146: syntax error : missing ';' before identifier 'strB'
F:\[C ]\demo1\demo1Dlg.cpp(178) : error C2065: 'strB' : undeclared identifier
F:\[C ]\demo1\demo1Dlg.cpp(193) : error C2065: 'Cstring' : undeclared identifier
F:\[C ]\demo1\demo1Dlg.cpp(193) : error C2146: syntax error : missing ';' before identifier 'strMsg'
F:\[C ]\demo1\demo1Dlg.cpp(193) : error C2065: 'strMsg' : undeclared identifier
F:\[C ]\demo1\demo1Dlg.cpp(194) : error C2228: left of '.Format' must have class/struct/union type
执行 cl.exe 时出错.

demo1.exe - 1 error(s), 0 warning(s)

 

 

解决方案：是"CString"， 不是"cstring", 也不是"Cstring"