dcsimg

Mouse Over Special Efects

Environment: This was built using Visual C++ 6.0 SP 2.
I used 16-bit color bitmaps, so if your resolution is set to 256 colors, it will probably not look very pleasing.

This is an updated version to my original posting. I have taken the comments that I received and have come up with a better version of the code. My thanks to Anatoly Ivasyuk, Jacques, and Dave Montgomery for their comments.

I needed a way to change a bitmap when the mouse went over it, and also to detect if the user pressed the mouse button. What I came up with was the following quick and easy solution.


void CMouseTrackDlg::OnMouseMove(UINT nFlags, CPoint point) 
{	
	m_Picture.GetWindowRect(&rect);
	ClientToScreen(&point);

	if (rect.PtInRect(point))
	{ 		      
		m_Picture.SetBitmap(bitmap2);		
	} 	      
	else 
	{
		m_Picture.SetBitmap(bitmap1);
	}	

	CDialog::OnMouseMove(nFlags, point);
}
All I did here was check to see if the mouse had entered into the bitmap. If it had, a different bitmap is displayed.

void CMouseTrackDlg::OnLButtonUp(UINT nFlags, CPoint point) 
{	
	m_Picture.GetWindowRect(&rect);
	ClientToScreen(&point);

	if(rect.PtInRect(point))
		AfxMessageBox("You pressed the Visual C++ bitmap", MB_OK);
		
	CDialog::OnLButtonUp(nFlags, point);
}
Here I just wanted to check if the user pressed the left mouse button while inside the bitmap.

Make sure to load the bitmaps:


BOOL CMouseTrackDlg::OnInitDialog()
{
	CDialog::OnInitDialog();

	// Set the icon for this dialog.  The framework does this automatically
	//  when the application's main window is not a dialog
	SetIcon(m_hIcon, TRUE);			// Set big icon
	SetIcon(m_hIcon, FALSE);		// Set small icon
	
	// TODO: Add extra initialization here
	
	bitmap1.LoadBitmap(IDB_BITMAP1);
	bitmap2.LoadBitmap(IDB_BITMAP2);
	
	return TRUE;  // return TRUE  unless you set the focus to a control
}
And make sure to initially declare the bitmaps, in this case there are only two. In addition to the bitmaps, you can see I declared a CRect which is used in the code above.

private:
	CRect rect;
	CBitmap bitmap1;
	CBitmap bitmap2;
Finally:

void CMouseTrackDlg::OnActivate(UINT nState, CWnd* pWndOther, BOOL bMinimized) 
{
	CDialog::OnActivate(nState, pWndOther, bMinimized);
	
	if(nState == WA_INACTIVE)
		m_Picture.SetBitmap(bitmap1);	
}
Here I mapped the OnActivate message to the dialog (CMouseTrackDlg) and if the dialog has lost its focus, then the orginal bitmap is displayed.

Download demo project - 13 KB

Download source - 21.7 KB



This article was originally published on May 1st, 1999

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