视图问答6则:
1,怎样改变视图的大小?
一般,你能改变试图大小依靠 MoveWindow()
MFC应用程序,视图是所围绕其框架的子窗口,获取其框架的指针GetParentFrame(),然后
依靠MoveWindow()改变框架大小,视图大小自动跟随框架大小改变。
2,如何改变一个CFormView的大小?
首先,你要在你的CFormView中重载OnInitialUpdate()函数,该函数声明如下:
virtual void OnInitialUpdate();
在OnInitialUpdate()添加如下代码:
void ClikethisView::OnInitialUpdate()//ClikethisView从CFormView继承而来
{
// Make the window the size of the main dialog.
CFormView::OnInitialUpdate();
GetParentFrame()->RecalcLayout();
ResizeParentToFit( /*FALSE*/ );
}
3,如何改变一个视图的背景?
想改变CView、CFrameWnd或者CWnd的背景,需要处理WM_ERASEBKGND 消息。
像下面演示的这样:
BOOL CSampleView::OnEraseBkgnd(CDC* pDC)
{
// 设置背景画刷颜色
CBrush backBrush(RGB(255, 128, 128));
// 保存旧画刷
CBrush* pOldBrush = pDC->SelectObject(&backBrush);
CRect rect;
pDC->GetClipBox(&rect); // 擦掉所要画的区域
pDC->PatBlt(rect.left, rect.top, rect.Width(),
rect.Height(), PATCOPY);
pDC->SelectObject(pOldBrush);
return TRUE;
}
4,改变对话框背景颜色后,如何使控件的背景颜色和对话框背景颜色统一?
请看下面代码: 重载画控件的消息。
HBRUSH dlgtest::OnCtlColor(CDC* pDC, CWnd* pWnd, UINT nCtlColor)
{
switch (nCtlColor)
{
case CTLCOLOR_BTN://按钮?
case CTLCOLOR_STATIC://我们所需要改画的静态
{
pDC->SetBkMode(TRANSPARENT);
}
case CTLCOLOR_DLG:
{
CBrush* back_brush;
COLORREF color;
color = (COLORREF) GetSysColor(COLOR_BTNFACE);
back_brush = new CBrush(color);
return (HBRUSH) (back_brush->m_hObject);
}
}
return(CFormView::OnCtlColor(pDC, pWnd, nCtlColor));
}
5,如何获得当前视图的指针?
((CFrameWnd*) AfxGetApp()->m_pMainWnd))->GetActiveDocument();
或者
((CFrameWnd*)(AfxGetApp()->m_pMainWnd))->GetActiveView();
6,如何获得MDI程序的所有视图?
下面函数对你有用:
CDocument::GetFirstViewPosition(); // DOCCORE.CPP
CDocument::GetNextView(); // DOCCORE.CPP
CMultiDocTemplate::GetFirstDocPosition(); // DOCMULTI.CPP
CMultiDocTemplate::GetNextDoc(); // DOCMULTI.CPP
文档精彩问答:
1,如何获得当前文档指针?
参照:上面“如何获得当前视图指针?”
2,文档什么时候被破坏?
单文档程序的文档当程序退出时被破坏。
多文档程序在最后一个视图关闭时被破坏。
3,如何获得当前打开文档的列表?
下面代码,MyApp从CWinApp继承而来,MyApp的成员变量:
CPtrList m_templateList
void CMyApp::GetDocumentList(CObList * pDocList)
{
ASSERT(pDocList->IsEmpty());
POSITION pos = m_templateList.GetHeadPosition();
while (pos)
{
CDocTemplate* pTemplate =
(CDocTemplate*)m_templateList.GetNext(pos);
POSITION pos2 = pTemplate->GetFirstDocPosition();
while (pos2)
{
CDocument * pDocument;
if ((pDocument=pTemplate->GetNextDoc(pos2)) != NULL)
pDocList->AddHead(pDocument);
}
}
}
4,如何不叫我的程序自动打开文档?
在InitInstance()函数中
cmdInfo.m_nShellCommand = CCommandLineInfo::FileNothing
1.如何让我的程序运行的时候最大化?
(1)在appwizard第4步选择“advanced"从中选择Mainframe的Maximized
(2)对于MDI程序,在CWinApp::InitInstance() 中做下面改动
// Create main MDI Frame window.
CMainFrame* pMainFrame = new CMainFrame;
if (!pMainFrame->LoadFrame(IDR_MAINFRAME))
return FALSE;
m_nCmdShow = SW_SHOWMAXIMIZED; // 注意添加此行!!!
pMainFrame->ShowWindow(m_nCmdShow);
pMainFrame->UpdateWindow();
m_pMainWnd = pMainFrame;
(3)对于SDI程序,在CWinApp::InitInstance() 中的OnFileNew()调用之前
m_nCmdShow = SW_SHOWMAXIMIZED;
// 下面创建空文档
OnFileNew();
2,如何给其他线程发消息?
用SendNotifyMessage() 函数。
3,如何让我的程序只运行一次?
const char* MyMainWndClassName = "MyMainWndXQW"
BOOL CMyApp::InitApplication()
{
// Call base class. Default version does nothing.
CWinApp::InitApplication();
WNDCLASS wndcls;
// Start with NULL defaults.
memset(&wndcls, 0, sizeof(WNDCLASS));
// Get class information for default window class.
::GetClassInfo(AfxGetInstanceHandle(),"AfxFrameOrView",&wndcls);
// Substitute unique class name for new class.
wndcls.lpszClassName = MyMainWndClassName;
// Register new class and return the result code.
return ::RegisterClass(&wndcls);
}
BOOL CMyApp::FirstInstance()
{
CWnd *PrevCWnd, *ChildCWnd;
// Determine if another window with our class name exists.
PrevCWnd = CWnd::FindWindow(MyMainWndClassName, NULL);
if (PrevCWnd != NULL)
{
// If so, does it have any pop-ups?
ChildCWnd=PrevCWnd->GetLastActivePopup();
// Bring the main window to the top.
PrevCWnd->BringWindowToTop();
// If iconic, restore the main window.
if (PrevCWnd->IsIconic())
PrevCWnd->ShowWindow(SW_RESTORE);
// If there are pop-ups, bring them along too!
if (PrevCWnd != ChildCWnd)
ChildCWnd->BringWindowToTop();
// Return FALSE. This isn't the first instance
// and we are done activating the previous one.
return FALSE;
}
else
// First instance. Proceed as normal.
return TRUE;
}
CMyApp::InitInstance()
{
if (!FirstInstance())
return FALSE;
// ...
}
4,MDI程序,关闭子窗口同时关闭父窗口,该如何做?
在子窗口的OnClose函数里添加
ASSERT(AfxGetMainWnd() != NULL);
AfxGetMainWnd()->SendMessage(WM_CLOSE);
菜单问题:
1,我在程序中用了MenuBar,结果找不到菜单了,我的方法是:
CMenu *menu;
menu = GetMenu()->GetSubMenu(0);
答:
AfxGetApp()->m_pMainWnd->GetMenu()->GetSubMenu(0);
2,如何动态修改MainFrame的菜单?
CMenu newMenu;
newMenu.LoadMenu (IDR_MENU1);
AfxGetMainWnd()->SetMenu( &newMenu );
AfxGetMainWnd()->DrawMenuBar();
newMenu.Detach ();