Advanced MFC Programming

Chapter 6. Dialog Box
}
TOOLTIPTEXT *pTTT=(TOOLTIPTEXT *)pNMHDR;
UINT nID=pNMHDR->idFrom;
if(pTTT->uFlags & TTF_IDISHWND)
{
nID=::GetDlgCtrlID((HWND)nID);
if(nID)
{
pTTT->lpszText=MAKEINTRESOURCE(nID);
pTTT->hinst=AfxGetResourceHandle();
return TRUE;
}
}
return FALSE;
First the ID of the control is obtained. If the control is a window, this ID will be a valid handle. We can
retrieve the control’s resource ID by calling fucntion ::GetDlgCtrlID(…). Next, the resource ID is
assigned to member lpszText, and the application’s instance handle is assigned to member hinst.
With this method, we can only implement a tool tip which contains maximum of 80 characters. To
implement longer tool tips, we need to provide our own buffer and assign its address to member lpszText.
In this case, we do not need to assign the application’s instance handle to member hinst.
After adding the above implementation, we can just add string resources whose IDs are the same with
the resource IDs of the controls. By doing this, the tool tip will automatically implemented for them.
6.8 Tool Bar and Status Bar in Dialog Box
By default, the dialog box does not support tool bar and status bar implementation. Because a dialog
box can contain various intuitive controls, it is often not necessary to implement extra tool bar and status
bar. But sometimes the tool bar and status bar are helpful, especially when we want to implement a row of
buttons with the same size. In this case, we can also easily implement the tool tips and flybys on the status
bar.
Frame Window
In a standard SDI or MDI application, tool bar and status bar can be implemented by declaring
CToolBar and CStatusBar type variables in class CMainFrame (They will be created in function
CMainFrame::OnCreate(…)). In a dialog-based application, the frame window is the dialog box itself, so we
need to embed CToolBar and CStatusBar type variables in the CDialog derived class and create them in
function CDialog::OnInitDialog().
However, unlike CFrameWnd, class CDialog is not specially designed to work together with status bar
and tool bar, so it lacks some features that are owned by class CFrameWnd: first, it does not support
automatic tool tip implementation, so we have to write TTN_NEEDTEXT message handler for displaying tool
tips; second, it does not support flyby implementation, so we also need to add other message handlers in
order to enable flybys.
Flyby Related Messages
In MFC, there are two un-documented messages that are used for flyby implementation. When a flyby
text for certain control needs to be displayed, the frame window will receive message
WM_SETMESSAGESTRING. Also, when a flyby needs to be removed, the frame window will receive another
message: WM_POPMESSAGESTRING.
Tool Bar Resource
Sample 6.8-1\DB demonstrates how to implement tool bar and status bar in a dialog based application.
The sample is generated by Application Wizard, with a tool bar resource IDD_DB_DIALOG added later on.
This ID is the same with the dialog template ID, which is convenient for tool bar implementation.
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