Question

MFC问题请教！ 显示结果：如下图;编译通过，连接失败？请问怎么改正······

#include "afxwin.h"

class CMyApp : public CWinApp
{
public:
CMyApp();
public:
virtual BOOL InitInstance();

};
CMyApp sha;

class CMainFrame : public CFrameWnd
{
public:
CMainFrame()
{ //创建窗口
Create(0,"我的窗口",WS_OVERLAPPEDWINDOW,CRect(0,0,400,300));
}
protected:
afx_msg void OnLButtonDown(UINT,CPoint);
DECLARE_MESSAGE_MAP()
};

BEGIN_MESSAGE_MAP(CMainFrame, CFrameWnd)
ON_WM_LBUTTONDOWN()
END_MESSAGE_MAP()

void CMainFrame::OnLButtonDown(UINT nFlags,CPoint point)
{
MessageBox("消息框！");
CMainFrame::OnLButtonDown(nFlags,point);
}

BOOL CMyApp::InitInstance()
{
m_pMainWnd=new CMainFrame();
m_pMainWnd->ShowWindow(SW_SHOW);
m_pMainWnd->UpdateWindow();
return TRUE;
}

error LNK2001: unresolved external symbol "public: __thiscall CMyApp::CMyApp(void)" (??0CMyApp@@QAE@XZ)
Debug/书上第一个MFC.exe : fatal error LNK1120: 1 unresolved externals
Error executing link.exe.

Answer 1

//加上
CMyApp::CMyApp()
{
}