MFC-UI相关

以下代码中的函数均为对话框消息响应函数或虚函数。

1.控件大小随窗口大小改变

void CclientDlg::OnSize(UINT nType, int cx, int cy)
{
    if (cx == 0 || cy == 0)
    {
	return;
    }
    CDialog::OnSize(nType, cx, cy);

    CWnd *pWnd = GetWindow(GW_CHILD);
    while(pWnd)
    {
	CRect rc;
	pWnd->GetWindowRect(rc);
	ScreenToClient(&rc);
	rc.left = rc.left * cx / m_rect.Width();
	rc.right = rc.right * cx / m_rect.Width();
	rc.top = rc.top * cy / m_rect.Height();
	rc.bottom = rc.bottom * cy / m_rect.Height();
	pWnd->MoveWindow(rc);
	pWnd = pWnd->GetNextWindow();
    }
    m_rect.SetRect(0, 0, cx, cy);
}

m_rect为全局变量，在OnInitDialog()里初始化：GetClientRect(m_rect)

2.给对话框添加背景图

void CLogin::OnPaint()
{
    CPaintDC dc(this);
    CRect rc;
    GetClientRect(&rc);
    CDC dcMem;
    dcMem.CreateCompatibleDC(&dc);
    CBitmap bmpBackground;
    bmpBackground.LoadBitmap(IDB_LOGINBG);
    BITMAP bitmap;
    bmpBackground.GetBitmap(&bitmap);
    CBitmap* pbmpPri = dcMem.SelectObject(&bmpBackground);
    dc.SetStretchBltMode(COLORONCOLOR);
    dc.StretchBlt(0, 0, rc.Width(), rc.Height(), &dcMem, 
        0, 0,bitmap.bmWidth, bitmap.bmHeight, SRCCOPY);//图片拉伸到窗口大小
    //dc.BitBlt(0, 0, rc.Width(), rc.Height(), &dcMem, 0, 0, SRCCOPY);//图片不拉伸
}

IDB_LOGINBG为bmp格式资源图

3.对话框背景局部透明

BOOL CLogin::OnInitDialog()
{
    ::SetWindowLong(m_hWnd, GWL_EXSTYLE, GetWindowLong(m_hWnd, GWL_EXSTYLE) | WS_EX_LAYERED);  
    ::SetLayeredWindowAttributes( m_hWnd, RGB(0, 255, 0), 0, LWA_COLORKEY);

    return TRUE;
}

RGB(0, 255, 0)为变透明的颜色，上述代码会将对话框所有绿色区域变成透明。LWA_COLORKEY为LWA_ALPHA时可以使整个窗口透明，并用第三个参数控制透明度。

4.控件背景颜色与字体颜色

HBRUSH CMessage::OnCtlColor(CDC* pDC, CWnd* pWnd, UINT nCtlColor)
{
    if(nCtlColor== CTLCOLOR_STATIC)//根据控件类型
    //if (pWnd->GetDlgCtrlID() == IDC_TITLE)//根据控件ID
    { 
        pDC->SetBkMode(TRANSPARENT);
	pDC->SetTextColor(RGB(255,255,255));
        return (HBRUSH)GetStockObject(NULL_BRUSH);
        //return (HBRUSH)CreateSolidBrush(RGB(255, 255, 255));//设置背景颜色
    }
    HBRUSH hbr = CDialogEx::OnCtlColor(pDC, pWnd, nCtlColor);
    return hbr;
}

控件背景为透明时，static控件内容改变会出现文字叠加现象，因此每次改变文字后都要用RedrawWindow(rect)来重新绘制控件区域。

5.非标题栏区域鼠标拖动窗口

void CVideoPlayer::OnLButtonDown(UINT nFlags, CPoint point)
{
    PostMessage(WM_NCLBUTTONDOWN,HTCAPTION,MAKELPARAM(point.x,point.y));
    CDialog::OnLButtonDown(nFlags, point);
}

6.使对话框不响应esc，enter， alt+f4

BOOL CVideoPlayer::PreTranslateMessage(MSG* pMsg)
{
    if(pMsg->message == WM_KEYDOWN)
    {
	if (pMsg->wParam==VK_ESCAPE || pMsg->wParam==VK_RETURN)
	{
            return TRUE;  
	}
    }
    if (pMsg->message == WM_SYSKEYDOWN && pMsg->wParam == VK_F4 )  
    {
 	return TRUE;
    }
    return CDialog::PreTranslateMessage(pMsg);
}

7.slider获取拖动后放开鼠标时的pos

void CVideoPlayer::OnHScroll(UINT nSBCode, UINT nPos, CScrollBar* pScrollBar)
{
    if (nSBCode == TB_THUMBPOSITION && pScrollBar == GetDlgItem(IDC_VIDEOSLIDER))
    {
	//nPos为要获得的值
    }
    CDialogEx::OnHScroll(nSBCode, nPos, pScrollBar);
}