为什么创建视图会失败？！

[yzhouen]

我在propertypage 指定RECT里创建一个VIEW,为什么会创建失败？
创建代码如下：
CCreateContext pContext;
CWnd* pFrameWnd = this;
pContext.m_pCurrentDoc = NULL;
pContext.m_pNewViewClass = RUNTIME_CLASS(CZoomView);
pView =(CZoomView *) ((CFrameWnd*)pFrameWnd)->CreateView(&pContext);
ASSERT(pView);
pView->ShowWindow(SW_NORMAL);
pView->MoveWindow(rectpic);

在CFrameWnd::CreateView的ASSERT_KINDOF(CWnd, pView);有问题
CWnd* CFrameWnd::CreateView(CCreateContext* pContext, UINT nID)
{
ASSERT(m_hWnd != NULL);
ASSERT(::IsWindow(m_hWnd));
ASSERT(pContext != NULL);
ASSERT(pContext->m_pNewViewClass != NULL);

// Note: can be a CWnd with PostNcDestroy self cleanup
CWnd* pView = (CWnd*)pContext->m_pNewViewClass->CreateObject();
if (pView == NULL)
{
TRACE1("Warning: Dynamic create of view type %hs failed.\n",
pContext->m_pNewViewClass->m_lpszClassName);
return NULL;
}
ASSERT_KINDOF(CWnd, pView); //单步运行到这里就无法继续往下执行了
...............
}

[yzhouen]

10楼的pXXXView 和 m_hParent 变量是怎么来的？

[yzhouen]

回复楼上，我把你的这段代码添进去是正常的，为什么改成我自己的VIEW就不行了呢？
CZoomView *pView = new CZoomView();
CRuntimeClass * pViewClass = RUNTIME_CLASS(CZoomView);
CCreateContext context;
context.m_pCurrentFrame = NULL;
context.m_pCurrentDoc = NULL;
context.m_pNewViewClass = pViewClass;
context.m_pNewDocTemplate = NULL;

CRect rc;
m_pParentWnd = new CWnd;
m_pParentWnd->Attach(pView->m_hWnd);
m_ViewWnd.GetClientRect(&rc);

pView->Create(NULL,NULL,WS_CHILD|WS_VISIBLE,rc,&m_ViewWnd,11,&context);

[yzhouen]

CZoomView是由CScrollView派生的


#if !defined(AFX_ZOOMVIEW_H__461510AD_E0E4_4CB6_B4B7_3E186AC2B08C__INCLUDED_)
#define AFX_ZOOMVIEW_H__461510AD_E0E4_4CB6_B4B7_3E186AC2B08C__INCLUDED_

#if _MSC_VER > 1000
#pragma once
#endif // _MSC_VER > 1000
// ZoomView.h : header file
//


class CZoomView : public CScrollView
{
protected:
public:
CZoomView(); // protected constructor used by dynamic creation
DECLARE_DYNAMIC(CZoomView)

// Attributes
public:
// Flicker free attributes
CDC* m_pdcMemory;
CBitmap* m_pBitmap;
BOOL m_bInitialSize;

protected:
// Zooom attributes
float m_zoomFactor;
float m_minZoomFactor;
float m_maxZoomFactor;
CSize m_line;
CSize m_page;
CSize m_layout;
CSize m_displaySize;

// Operations
public:
// Display Operation /////////////////////////////////////////////////////
int SetMapMode(CDC* pDC);
void SetDisplaySize(void);
void SetZoomScale(float fScale);
void SetZoomArea(CRect zoomRect);
CPoint GetCenterScrollPosition(void);
void LPtoDP(LPPOINT lpPoint);
void LPtoDP(LPRECT lpRect);
void LPtoDP(LPSIZE lpSize);
void DPtoLP(LPPOINT lpPoint);
void DPtoLP(LPRECT lpRect);
void DPtoLP(LPSIZE lpSize);
CSize GetDisplaySize() {return m_displaySize;};
//////////////////////////////////////////////////////////////////////////

int FloatToInt(float fNumber);

protected:
void SetZoomFactor(float fZoomFactor);

// Overrides
// ClassWizard generated virtual function overrides
//{{AFX_VIRTUAL(CZoomView)
protected:
public:
virtual void OnDraw(CDC* pDC); // overridden to draw this view
virtual void OnInitialUpdate(); // first time after construct
//}}AFX_VIRTUAL

// Implementation
protected:
public:
virtual ~CZoomView();
#ifdef _DEBUG
virtual void AssertValid() const;
virtual void Dump(CDumpContext& dc) const;
#endif

// Generated message map functions
//{{AFX_MSG(CZoomView)
afx_msg void OnPaint();
afx_msg void OnSize(UINT nType, int cx, int cy);
afx_msg BOOL OnEraseBkgnd(CDC* pDC);
//}}AFX_MSG
DECLARE_MESSAGE_MAP()
};

/////////////////////////////////////////////////////////////////////////////

//{{AFX_INSERT_LOCATION}}
// Microsoft Visual C++ will insert additional declarations immediately before the previous line.

#endif // !defined(AFX_ZOOMVIEW_H__461510AD_E0E4_4CB6_B4B7_3E186AC2B08C__INCLUDED_)

[job82824]

学习下。
MSDN注解：CreateView
--Use this member function to create "views" that are not CView-derived within a frame. After calling CreateView, you must manually set the view to active and set it to be visible; these tasks are not automatically performed by CreateView
--使用这个函数来创建的views应该是框架当中的非CView类的派生类(我想楼主的CScrollView应该是CView类的派生类吧？)。在创建后，你必须手动激活该视，并设置它为可见；这些工作并不能由CreateView来完成.
个人感觉还不如在矩形区域内创建一个窗口CWnd呢，然后在里边显示需要看到的内容？

[yzhouen]

再顶一次

[yzhgr]

学习一下

[bao20080513shengbin]

顶起

[eagerle01]

帮顶

[yzhouen]

人呢？分数可以再加！

[yzhouen]

再UP一下，问题仍然没有解决

[shakeyou123]

人工UP

[yzhouen]

没有来实质性解决问题的吗？

[wu_qing_yun]

楼主太富有了

[yzhouen]

这个问题解决200分全部给他

[晒月光的青蛙]

=帮顶定啦

[dl551djs]

看的眼花
也没看出啥

[MoXiaoRab]

代码太多，眼看花了...

[MoXiaoRab]

OnInitialUpdate()贴出来看看，我估计这个写得有问题

[MoXiaoRab]

void CZoomView::OnInitialUpdate()
{
CScrollView::OnInitialUpdate();

// TODO: Add your specialized code here and/or call the base class
CSize sizeTotal;
sizeTotal.cx = sizeTotal.cy = 1000;
SetScrollSizes(MM_TEXT, sizeTotal);
}

[yzhouen]

void CZoomView::OnInitialUpdate()
{
CScrollView::OnInitialUpdate();

m_layout.cx = 1000;
m_layout.cy = 40000;

m_page.cx = m_layout.cx/2;
m_page.cy = m_layout.cy/2;
m_line.cx = m_layout.cx/50;
m_line.cy = m_layout.cy/50;
SetScrollSizes(MM_TEXT, m_layout, m_page, m_line);

m_bInitialSize = TRUE;

if (m_pdcMemory->GetSafeHdc() == NULL)
{
CClientDC dc(this);
OnPrepareDC(&dc);
m_pdcMemory->CreateCompatibleDC(&dc);

// makes bitmap same size as display window
CRect clientRect(0,0,0,0);
GetClientRect(clientRect);
if (m_pBitmap != NULL)
{
delete m_pBitmap;
m_pBitmap = NULL;
}
m_pBitmap = new CBitmap();
m_pBitmap->CreateCompatibleBitmap(&dc, clientRect.right,
clientRect.bottom);
}
}