- CMFCTabCtrl::EnableActiveTabCloseButton
用于在CMFCTabCtrl的Tab页显示一个关闭按钮，看看关闭按钮怎么实现：
- void
CMFCBaseTabCtrl::OnLButtonDown(UINT nFlags, CPoint point) - {
- m_bWindowPosChanged = FALSE;
- CWnd::OnLButtonDown(nFlags, point);
-
if
(m_rectCloseButton.PtInRect(point)) - {
- m_bTabCloseButtonPressed = TRUE;
- RedrawWindow(m_rectCloseButton);
-
return
; - }
- ...
-
void
CMFCBaseTabCtrl::OnLButtonUp(UINT nFlags, CPoint point) - {
-
if
(m_bTabCloseButtonPressed) - {
- m_bTabCloseButtonPressed = FALSE;
- m_bTabCloseButtonHighlighted = FALSE;
- RedrawWindow(m_rectCloseButton);
-
if
(m_rectCloseButton.PtInRect(point)) - {
- CWnd* pWndActive = GetActiveWnd();
-
if
(pWndActive != NULL) - {
- pWndActive->SendMessage(WM_CLOSE);
- }
-
return
; - }
- }
- ...
应该就这些了。
在例子TabbedView中添加这个功能：
- int
CTabbedViewView::OnCreate(LPCREATESTRUCT lpCreateStruct) - {
-
if
(CTabView::OnCreate(lpCreateStruct) == -1) -
return
-1; - AddView (RUNTIME_CLASS (CView1), _T(
"Simple"
), 100); - AddView (RUNTIME_CLASS (CView2), _T(
"List"
), 101); - AddView (RUNTIME_CLASS (CView3), _T(
"Form"
), 102); - AddView (RUNTIME_CLASS (CView4), _T(
"ScrollView"
), 102); - m_wndTabs.EnableActiveTabCloseButton();
-
return
0; - }
然后点击一个页面上的关闭按钮，会发现这个tab页并没有消失，而切换到其他页面，程序就中断了，问题出在：
- BOOL
CMFCTabCtrl::SetActiveTab(
int
iTab) - {
- ...
-
if
(m_iActiveTab != -1 && m_bHideInactiveWnd) - {
-
//-------------------- -
// Hide active window: -
//-------------------- - CWnd* pWndActive = GetActiveWnd();
-
if
(pWndActive != NULL) - {
- pWndActive->ShowWindow(SW_HIDE);
- }
- }
由于窗口已经销毁，而该Tab页仍然存在，所以m_iActiveTab就是被销毁的窗口所在页面，pWndActive是已经被销毁的窗口，自然调用其ShowWindow方法就出错了。