Windows NT Systems Programming: Spring 1999

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Where are we?
What we need:

• Select a Folder
• Select a Message in a Folder
• Edit a Message

What we know:

• Create Buttons (CButton)
• Create Menus (resource compiler)
• Edit boxes (CEdit)
• List items (CListBox)

What we still need to know:

• Create dialog boxes as child windows (first we will build a home grown version, then use resource editor)

Child Dialog Window

Changes to CMsgFolder Class

• Change from windows.h to afxwin.h (because of MFC)
• Made listMsgs a public member: access needed to build dialog window
  In particular, need to put list of messages in a CListBox control

Changing the Window Title

• Decision: change title bar to show which folder is opened
• Can also be used for diagnostic messages

	m_editSelection.GetWindowText(folder);
	if(!msgFolderApp.msgFolder.OpenMsgFolder(folder))	
		MessageBox("Message Folder Corrupted!", "ERROR");
	else {
		SetWindowText("Message Folder Demo [" + folder + "]");

CMsgDlg Class

• Keep all dialog window controls in its own child window (unlike the previous example which drew the dialog controls in the main window)
• Demonstrate multiple MESSAGE_MAPs

(source code here)

CMsgDlg Declaration

#define IDB_OPEN_MSG 206
#define IDB_CANCEL_MSG 207
#define IDC_MSG_SELECTION 208
#define IDC_MSG_LISTBOX 209

#include "ListMsgs.h"
class CMsgDlg : public CWnd // not CFrameWnd
{
public:
	CMsgDlg();
	~CMsgDlg();
	void MakeDlg(CRect, CWnd*, CListMsgs&); // does the dirty work
protected:
	afx_msg void OnOpenMsg();
	afx_msg void OnCancelOpenMsg();
	afx_msg void OnMsgSelection();
	afx_msg void OnMsgDblClk();
	DECLARE_MESSAGE_MAP()

private:
	// and clean up OpenMessageFolder controls
	void cleanUpOpenMsgDlg();
	CListBox m_lBoxMsgs; // List Box for Messages
	CButton m_btnOpenMsg;
	CButton m_btnCancelMsg;
	CStatic m_labelSelection;	// label for selection
	CEdit m_editSelection;
};
#endif

CMsgDlg Implementation File

//**************** Class for the Selecting Message Dialog Window
//******************************************
// CMsgDlg: class for displaying the message selection dialog
// Off loads message handling, etc from main window
// Modelled after dialog for opening a message folder
//
#include "CMsgDlg.h"
#include "listMsgs.h"

// Message map - for Message Dialog Class
BEGIN_MESSAGE_MAP( CMsgDlg, CWnd )
	ON_COMMAND(IDB_OPEN_MSG, OnOpenMsg)
	ON_COMMAND(IDB_CANCEL_MSG, OnCancelOpenMsg)
	ON_LBN_SELCHANGE(IDC_MSG_LISTBOX,OnMsgSelection)
	ON_LBN_DBLCLK(IDC_MSG_LISTBOX,OnMsgDblClk)
END_MESSAGE_MAP()


CMsgDlg::CMsgDlg()
{
}
CMsgDlg::~CMsgDlg()
{
}


void CMsgDlg::OnOpenMsg()
{
	CString message;
	CString msgName;
	
	m_editSelection.GetWindowText(msgName);
	message = "You want to open " + msgName;
	MessageBox(message,"open Message");
	cleanUpOpenMsgDlg();


}
void CMsgDlg::OnCancelOpenMsg()
{
	cleanUpOpenMsgDlg();
}

void CMsgDlg::OnMsgSelection()
{
	CString selection;
	int nIndex = m_lBoxMsgs.GetCurSel();
	if (nIndex != LB_ERR) {
		m_lBoxMsgs.GetText(nIndex,selection);
		m_editSelection.SetWindowText(selection);
	}
}

void CMsgDlg::OnMsgDblClk()
{
	CString selection;

	int nIndex = m_lBoxMsgs.GetCurSel();
	if (nIndex != LB_ERR) {
		m_lBoxMsgs.GetText(nIndex,selection);
		m_editSelection.SetWindowText(selection);
		OnOpenMsg();
	}
}

// could we get away with only building the window once? and just changing its visibility
void CMsgDlg::MakeDlg(CRect rect, CWnd* parent, CListMsgs& listMsgs)
{
	Create(NULL, "Message Dialog", 
		WS_CHILD|WS_VISIBLE,
		CRect(0,0,700,500),
		parent,400);
	rect.right -= 100; // make room for buttons
	rect.bottom -= 100; // make room for selection
	m_lBoxMsgs.Create(WS_CHILD|WS_VISIBLE|LBS_STANDARD,rect,this,IDC_MSG_LISTBOX);
	m_labelSelection.Create("Selected Message:", WS_CHILD|WS_VISIBLE,
		CRect(CPoint(0,rect.bottom),CSize(200,25)),
		this);
	m_editSelection.Create(WS_CHILD|WS_VISIBLE|WS_BORDER,
		CRect(CPoint(210,rect.bottom),CSize(rect.right-110,25)),
		this,IDC_MSG_SELECTION);
	m_btnOpenMsg.Create("Open Msg", WS_CHILD|WS_VISIBLE|WS_TABSTOP|BS_PUSHBUTTON,
		CRect(CPoint(rect.right+5,0),CSize(75,30)),
		this,IDB_OPEN_MSG); 
	m_btnCancelMsg.Create("Cancel", WS_CHILD|WS_VISIBLE|WS_TABSTOP|BS_PUSHBUTTON,
		CRect(CPoint(rect.right+5,40),CSize(75,30)),
		this,IDB_CANCEL_MSG); 
	
	Item thisItem;
	for(int i = 1; i <= listMsgs.length(); i++) {
		listMsgs.GetItem(i, thisItem);
		m_lBoxMsgs.AddString(thisItem.topic);
	}
}

void CMsgDlg::cleanUpOpenMsgDlg()
{
	m_lBoxMsgs.DestroyWindow();
	m_labelSelection.DestroyWindow();
	m_btnCancelMsg.DestroyWindow();
	m_btnOpenMsg.DestroyWindow();
	m_editSelection.DestroyWindow();
	DestroyWindow();
}

Copyright chris wild 1999.
For problems or questions regarding this web contact [Dr. Wild].
Last updated: February 17, 1999.