VC++深入详解-第五章学习心得

这一章节主要讲解了文本相关的一些编程

插入符的使用

	CreateSolidCaret(100,200);//插入符的宽度和高度
	ShowCaret();

插入符的一般使用方法

int CTestView::OnCreate(LPCREATESTRUCT lpCreateStruct) 
{
	if (CView::OnCreate(lpCreateStruct) == -1)
		return -1;
	
	// TODO: Add your specialized creation code here
	//CreateSolidCaret(20,100);
	//ShowCaret();

	CClientDC dc(this);
	//定义文本结构变量
	TEXTMETRIC tm;
	//获取设备描述表中的文本信息
	dc.GetTextMetrics(&tm);
	//根据文本大小创建合适的光标
	CreateSolidCaret(tm.tmAveCharWidth/8,tm.tmAveCharWidth); //实践下来这样显示的光标还是看上去不合理tm.tmAveCharWidth*2看上去还行
	//显示光标
	ShowCaret();

	SetTimer(5,100,NULL);
	return 0;
}

当窗口的大小发生变化时，显示窗口里的内容会消失，是由于OnDraw函数

void CTestView::OnDraw(CDC* pDC)
{
	CTestDoc* pDoc = GetDocument();
	ASSERT_VALID(pDoc);
	// TODO: add draw code for native data here
	CString str("VC++深入详解");
	pDC->TextOut(50,50,str);

	CSize cz = pDC->GetTextExtent(str);

	str.LoadString(IDS_STRING61446);
	pDC->TextOut(0,200,str);
	//路径层
	pDC->BeginPath();
	pDC->Rectangle(50,50,50+cz.cx,50+cz.cy);
	pDC->EndPath();
	//裁剪区域
	pDC->SelectClipPath(RGN_DIFF);
	//绘制网格
	for (int i = 0; i < 300; i+=10)
	{
		pDC->MoveTo(0,i);
		pDC->LineTo(300,i);
		pDC->MoveTo(i,0);
		pDC->LineTo(i,300);
	}
}

 下面是关于字符输入的demo

void CTestView::OnChar(UINT nChar, UINT nRepCnt, UINT nFlags) 
{
	// TODO: Add your message handler code here and/or call default
	CClientDC dc(this);
	CFont font;
	font.CreatePointFont(300,"华文行楷",NULL);
	CFont *pOldFont = dc.SelectObject(&font);
	TEXTMETRIC tm;
	dc.GetTextMetrics(&tm);
	if(0x0d == nChar) //如果是回车键
	{
		m_strLine.Empty();
		m_ptOrign.y += tm.tmHeight;
	}
	else if (0x08 == nChar)//如果是后退键
	{
		COLORREF clr = dc.SetTextColor(dc.GetBkColor());	//删除的实现方法：设置字符串颜色为窗体背景颜色
		dc.TextOut(m_ptOrign.x,m_ptOrign.y,m_strLine);	//输出字符串
		m_strLine = m_strLine.Left(m_strLine.GetLength()-1);	//去除字符串的末端字符
		dc.SetTextColor(clr);				//去除末端字符后颜色还原
	}
	else
	{
		m_strLine += nChar;
	}
	//光标跟随字符后面
	CSize sz = dc.GetTextExtent(m_strLine);
	CPoint pt;
	pt.x = m_ptOrign.x + sz.cx;
	pt.y = m_ptOrign.y;
	SetCaretPos(pt);
	dc.TextOut(m_ptOrign.x,m_ptOrign.y,m_strLine);
	dc.SelectObject(pOldFont);
	CView::OnChar(nChar, nRepCnt, nFlags);
}

定时器的应用，在onCreate函数里添加 SetTimer(1,100,NULL);

具体实现如下

void CTestView::OnTimer(UINT nIDEvent) 
{
	// TODO: Add your message handler code here and/or call default
	m_nWidth += 5;
	CClientDC dc(this);
	TEXTMETRIC tm;
	dc.GetTextMetrics(&tm);
	CRect rect;
	rect.left = 0;
	rect.top = 200;
	rect.right = m_nWidth;
	rect.bottom = rect.top + tm.tmHeight;

	dc.SetTextColor(RGB(255,0,0));
	CString str;
	str.LoadString(IDS_STRING61446);
	dc.DrawText(str,rect,DT_LEFT);

	rect.top = 150;
	rect.bottom = rect.top + tm.tmHeight;
	dc.DrawText(str,rect,DT_RIGHT);
	
	CSize sz = dc.GetTextExtent(str);
	if(m_nWidth > sz.cx)
	{
		m_nWidth = 0;
		dc.SetTextColor(RGB(0,255,0));
		dc.TextOut(0,200,str);
	}
	CView::OnTimer(nIDEvent);
}