SetModifiedFlag(TRUE); 出现chkesp.c line42错误？

[rushpixy]

程序是一个4×4的格子，点击格子会变色。
学习doc/view的，点击会出错，调试时发现是 SetModifiedFlag(TRUE) 出错
完整代码：http://pan.baidu.com/s/1mgNopSG
代码如下

BOOL CSdiSquaresDoc::OnNewDocument()
{
	if (!CDocument::OnNewDocument())
		return FALSE;

	// TODO: add reinitialization code here
	// (SDI documents will reuse this document)
	for (int i=0; i<4; i++)
	{
		for (int j=0; j<4; j++)
		{
			m_clrGrid[i][j] = RGB(0,255,0);
		}    
	}
	m_curColor = RGB(0,0,255);
	return TRUE;
}



/////////////////////////////////////////////////////////////////////////////
// CSdiSquaresDoc serialization

void CSdiSquaresDoc::Serialize(CArchive& ar)
{
	if (ar.IsStoring())
	{
		// TODO: add storing code here
		for (int i=0; i<4; i++)
		{
			for (int j=0; j<4; j++)
			{
				ar<<m_clrGrid[i][j];
			}
		}
		ar<<m_curColor;
	}
	else
	{
		// TODO: add loading code here
		for (int i=0; i<4; i++)
		{
			for (int j=0; j<4; j++)
			{
				ar>>m_clrGrid[i][j];
			}
		}
		ar>>m_curColor;
	}
}

/////////////////////////////////////////////////////////////////////////////
// CSdiSquaresDoc diagnostics

#ifdef _DEBUG
void CSdiSquaresDoc::AssertValid() const
{
	CDocument::AssertValid();
}

void CSdiSquaresDoc::Dump(CDumpContext& dc) const
{
	CDocument::Dump(dc);
}

COLORREF CSdiSquaresDoc::GetSquare(int i,int j)
{
	ASSERT(i>=0 && i<4 && j>=0 && j<4);
	return m_clrGrid[i][j];
}

void CSdiSquaresDoc::SetSquare(int i,int j,COLORREF color)
{
	ASSERT(i>=0 && i<4 && j>=0 && j<4);
	m_clrGrid[i][j]= color;
	SetModifiedFlag(TRUE);
	UpdateAllViews(NULL);
}

COLORREF CSdiSquaresDoc::GetCurColor()
{
	return m_curColor;
}


====================================================
void CSdiSquaresView::OnDraw(CDC* pDC)
{
	CSdiSquaresDoc* pDoc = GetDocument();
	ASSERT_VALID(pDoc);
	for (int i=0; i<4; i++)
	{
		for (int j=0; j<4; j++)
		{
			COLORREF color = pDoc->GetSquare(i,j);
			CBrush brush(color);
			int x1 = j*100+50;
			int y1 = i*100+50;
			int x2 = x1+100;
			int y2 = y1+100;
			CRect rect(x1,y1,x2,y2);
			pDC->FillRect(&rect,&brush);
		}
	}

	for (int x=50;x<=450;x+=100)		//竖线
	{
		pDC->MoveTo(x,50);
		pDC->LineTo(x,450);
	}
	for (int y=50;y<=450;y+=100)
	{
		pDC->MoveTo(50,y);
		pDC->LineTo(450,y);
	}
}

void CSdiSquaresView::OnLButtonDown(UINT nFlags, CPoint point) 
{
	// TODO: Add your message handler code here and/or call default

	if (point.x>50 && point.x<450 && point.y>50 && point.y<450)
	{
	int x=(point.x-50)/100;
	int y=(point.y-50)/100;
	CSdiSquaresDoc * pDoc = (CSdiSquaresDoc *)GetDC();
	COLORREF color = pDoc->GetCurColor();
	pDoc->SetSquare(x,y,color);
	}
}

[schlafenhamster]

1. CSdiSquaresDoc::CSdiSquaresDoc() { // TODO: add one-time construction code here for (int i=0; i<4; i++) { for (int j=0; j<4; j++) { m_clrGrid[i][j] = RGB(0,255,0); } } m_curColor = RGB(0,0,255); } 2. void CSdiSquaresView::OnLButtonDown(UINT nFlags, CPoint point) { // TODO: Add your message handler code here and/or call default CSdiSquaresDoc* pDoc = GetDocument(); ASSERT_VALID(pDoc); if (point.x>50 && point.x<450 && point.y>50 && point.y<450) { int x=(point.x-50)/100; int y=(point.y-50)/100; COLORREF color = pDoc->GetCurColor(); pDoc->SetSquare(x,y,color); } CView::OnLButtonDown(nFlags, point); } 3.与 void CSdiSquaresDoc::SetSquare(int i,int j,COLORREF color) { ASSERT(i>=0 && i<4 && j>=0 && j<4); m_clrGrid[i][j]= color; SetModifiedFlag(TRUE); UpdateAllViews(NULL); } 无关。 是 int x=(point.x-50)/100; int y=(point.y-50)/100; CSdiSquaresDoc * pDoc = (CSdiSquaresDoc *)GetDC(); 错了

[schlafenhamster]

4. 索引有问题： void CSdiSquaresDoc::SetSquare(int i,int j,COLORREF color) { ASSERT(i>=0 && i<4 && j>=0 && j<4); m_clrGrid[j][i]= color; SetModifiedFlag(TRUE); UpdateAllViews(NULL); }

[rushpixy]

感谢，