修改CDialog模态对话框函数DoModal 使对话框显示可以受WS_VISIBLE风格控制

调试追踪DoModal的执行过程发现对话框显示的位置在 CWnd::RunModalLoop(DWORD dwFlags)中

BOOL bShowIdle = (dwFlags & MLF_SHOWONIDLE) && !(GetStyle() & WS_VISIBLE);

……

if (bShowIdle)

{

ShowWindow(SW_SHOWNORMAL); //这里显示出来了

UpdateWindow();

bShowIdle = FALSE;

}

而CWnd::RunModalLoop(DWORD dwFlags)没有提供重载接口我们只能修改传入的参数

再返回到DoModal中我们发现 DWORD dwFlags = MLF_SHOWONIDLE;

于是我们修改DWORD dwFlags = 0;// MLF_SHOWONIDLE;

即达到了模态对话框也受WS_VISIBLE风格控制的效果

int CCcDlg::DoModal()
{
// TODO: Add your specialized code here and/or call the base class
// can be constructed with a resource template or InitModalIndirect
ASSERT(m_lpszTemplateName != NULL || m_hDialogTemplate != NULL ||
m_lpDialogTemplate != NULL);

// load resource as necessary
LPCDLGTEMPLATE lpDialogTemplate = m_lpDialogTemplate;
HGLOBAL hDialogTemplate = m_hDialogTemplate;
HINSTANCE hInst = AfxGetResourceHandle();
if (m_lpszTemplateName != NULL)
{
hInst = AfxFindResourceHandle(m_lpszTemplateName, RT_DIALOG);
HRSRC hResource = ::FindResource(hInst, m_lpszTemplateName, RT_DIALOG);
hDialogTemplate = LoadResource(hInst, hResource);
}
if (hDialogTemplate != NULL)
lpDialogTemplate = (LPCDLGTEMPLATE)LockResource(hDialogTemplate);

// return -1 in case of failure to load the dialog template resource
if (lpDialogTemplate == NULL)
return -1;

// disable parent (before creating dialog)
HWND hWndParent = PreModal();
//AfxUnhookWindowCreate();
BOOL bEnableParent = FALSE;
if (hWndParent != NULL && ::IsWindowEnabled(hWndParent))
{
::EnableWindow(hWndParent, FALSE);
bEnableParent = TRUE;
}

TRY
{
// create modeless dialog
//AfxHookWindowCreate(this);
if (CreateDlgIndirect(lpDialogTemplate,
CWnd::FromHandle(hWndParent), hInst))
{
if (m_nFlags & WF_CONTINUEMODAL)
{
// enter modal loop
DWORD dwFlags = 0;// MLF_SHOWONIDLE;
if (GetStyle() & DS_NOIDLEMSG)
dwFlags |= MLF_NOIDLEMSG;
VERIFY(RunModalLoop(dwFlags) == m_nModalResult);
}

// hide the window before enabling the parent, etc.
if (m_hWnd != NULL)
SetWindowPos(NULL, 0, 0, 0, 0, SWP_HIDEWINDOW|
SWP_NOSIZE|SWP_NOMOVE|SWP_NOACTIVATE|SWP_NOZORDER);
}
}
CATCH_ALL(e)
{
{ e->Delete(); }//DELETE_EXCEPTION(e);

m_nModalResult = -1;
}
END_CATCH_ALL

if (bEnableParent)
::EnableWindow(hWndParent, TRUE);
if (hWndParent != NULL && ::GetActiveWindow() == m_hWnd)
::SetActiveWindow(hWndParent);

// destroy modal window
DestroyWindow();
PostModal();

// unlock/free resources as necessary
if (m_lpszTemplateName != NULL || m_hDialogTemplate != NULL)
UnlockResource(hDialogTemplate);
if (m_lpszTemplateName != NULL)
FreeResource(hDialogTemplate);

return m_nModalResult;
// return CDialog::DoModal();
}