问题描述

MFC Dialog报错问题，m_hWnd为空

代码如下：
BOOL CVSOConnectorApp::InitInstance()
{
//m_pMainWnd = (CWnd*)malloc(sizeof(m_pMainWnd));
INITCOMMONCONTROLSEX InitCtrls;
InitCtrls.dwSize = sizeof(InitCtrls);

InitCtrls.dwICC = ICC_WIN95_CLASSES;
InitCommonControlsEx(&InitCtrls);

char buf[MAXBUFSIZE + 1];
char value[MAXPARAMETERLEN + 1];

CVSOConnectorDlg dlg;//报错地方，debug模式下只要执行到这就会报错，release下是ok的
m_pMainWnd = &dlg;

错误信息如图

解决方案

你创建变量还要DoModal才会真正生成对话框

 CVSOConnectorDlg dlg;
dlg.DoModal()

解决方案二：

CVSOConnectorDlg dlg;
dlg.Create(对话框资源id);

解决方案三：

有的，
CVSOConnectorDlg *dlg = new CVSOConnectorDlg;
m_pMainWnd = dlg;

    dlg->serverdetails.setServer(sd.getServer());
    dlg->serverdetails.setPort(sd.getPort());
    dlg->serverdetails.setUsername(sd.getUsername());
    dlg->serverdetails.setPassword(sd.getPassword());
    dlg->serverdetails.setDomain(sd.getDomain());
    dlg->serverdetails.setGatewayHostname(sd.getGatewayHostname());
    dlg->serverdetails.setFullScreen(true);

    if (pShellManager != NULL)
    {
        delete pShellManager;
    }

    return dlg->Create(IDD_VSOCONNECTOR_DIALOG);

解决方案四：

m_hWnd还是m_pMainWnd为空？
m_pMainWnd是什么类型

解决方案五：

要看一下CVSOConnectorDlg类的构造函数中写了什么

解决方案六：

将dlg换成CVSOConnectorDlg*，或者全局变量。
编译器bug！！！

解决方案七：

class CVSOConnectorDlg : public CDialogEx
{
// Construction
public:
CVSOConnectorDlg(CWnd* pParent = NULL); // standard constructor
~CVSOConnectorDlg();
// Dialog Data
enum { IDD = IDD_VSOCONNECTOR_DIALOG };

protected:
virtual void DoDataExchange(CDataExchange* pDX);    // DDX/DDV support

// Implementation
protected:
HICON m_hIcon;

// Generated message map functions
virtual BOOL OnInitDialog();
afx_msg void OnPaint();
afx_msg HCURSOR OnQueryDragIcon();
DECLARE_MESSAGE_MAP()

public:
CMstscax1 m_VSOConnector;
ServerDetails serverdetails;
afx_msg void OnBnClickedButton1();
INT_PTR DoModal();
DECLARE_EVENTSINK_MAP()
void OnDisconnectedMstscax1(long discReason);
void OnConnectedMstscax1();
//afx_msg void OnSize(UINT nType, int cx, int cy);

public:
CProgressBar pb;
void OnConnectingMstscax1();
void OnLogonErrorMstscax1(long lError);
afx_msg void OnSize(UINT nType, int cx, int cy);
CRect m_rect;
// afx_msg void OnNcPaint();
afx_msg void OnKillFocus(CWnd pNewWnd);
afx_msg int OnMouseActivate(CWnd* pDesktopWnd, UINT nHitTest, UINT message);
void OnRemoteProgramResultMstscax1(LPCTSTR bstrRemoteProgram, long lError, BOOL vbIsExecutable);
void OnRemoteProgramDisplayedMstscax1(BOOL vbDisplayed, unsigned long uDisplayInformation);
void OnIdleTimeoutNotificationMstscax1();
void OnConfirmCloseMstscax1(BOOL* pfAllowClose);
void OnWarningMstscax1(long warningCode);
void OnRequestContainerMinimizeMstscax1();
afx_msg void OnClose();
void OnEnterFullScreenModeMstscax1();
void OnLeaveFullScreenModeMstscax1();
void OnRequestGoFullScreenMstscax1();
void OnRequestLeaveFullScreenMstscax1();
void OnRemoteDesktopSizeChangeMstscax1(long width, long height);
};