problem with adding About Diaglog

tataxin

I want to create About dialog after created main dialog. All I did as follows: - create about dialog - in Resource.rc, I add this:

// create a line when right click dialog on taskbar
STRINGTABLE
BEGIN
IDS_ABOUTBOX "&About ..."
END

- in CMyDlg.h, declare

afx_msg void OnSysCommand(UINT nID, LPARAM lParam);

- in CMyDlg.cpp, implement this method:

void CMyDlg::OnSysCommand(UINT nID, LPARAM lParam)
{
/* set breakpoint to debug here */
if ((nID & 0xFFF0) == IDM_ABOUTBOX)
{
CAboutDlg dlgAbout;
dlgAbout.DoModal();
}
else
{
CDialog::OnSysCommand(nID, lParam);
}
}

- in CMyDlg.cpp, register notify

BEGIN_MESSAGE_MAP(CAboutDlg, CMyDlg)
ON_WM_SYSCOMMAND()
END_MESSAGE_MAP()

that's all, but it doesn't work. I try to debug and found that it doesn't come into OnSysComand() method. What do I miss here? Thank you very much, :)

SandipG

I guess you need to add the handler in the WinApp class. and by default MFC will add about dialog unless you explicitly removed the about dialog check box.

tataxin

Thank you for reply me, SandipG. I don't have WinApp class, it's MFC project with Dialog based.

SandipG

haha :D without application class you cant have MFC application. I am talking about the class which has Initinstance function.

David Crow

tataxin wrote:

BEGIN_MESSAGE_MAP(CAboutDlg, CMyDlg) ON_WM_SYSCOMMAND() END_MESSAGE_MAP()

This is the wrong message map. It should be:

BEGIN_MESSAGE_MAP(CMyDlg, CDialog)
ON_WM_SYSCOMMAND()
END_MESSAGE_MAP()

"Love people and use things, not love things and use people." - Unknown

"To have a respect for ourselves guides our morals; to have deference for others governs our manners." - Laurence Sterne

tataxin

Thank you DavidCrow :) It works, but with a little strange. Whenever I right click application in taskbar and select "About ...", nothing happens. Then, I press Alt, the About dialog shows up. I don't know why???? :confused:

David Crow

tataxin wrote:

It works, but with a little strange. Whenever I right click application in taskbar and select "About ...", nothing happens.

Does void CMyDlg::OnSysCommand() get called?

"Love people and use things, not love things and use people." - Unknown

"To have a respect for ourselves guides our morals; to have deference for others governs our manners." - Laurence Sterne

tataxin

yes, it does. Here is the source code of OnSysCommand:

void CMyDlg::OnSysCommand(UINT nID, LPARAM lParam)
{
if ((nID & 0xFFF0) == IDM_ABOUTBOX)
{
CAboutDlg dlgAbout;
dlgAbout.DoModal(); // stop here (1)
}
else
{
CDialog::OnSysCommand(nID, lParam);
}
}

When I try to debug, it stops at (1) until I press Alt. After that, the About dialog shows.

modified on Monday, June 2, 2008 3:51 AM