绘图程序

开发平台：
Visual C++

LineComboBox.cpp：源码内容
							//////////////////////////////////////////////////////////////////////
// CLASS    :  CLineComboBox
// ABSTRACT :  线条宽度选择组合框
// NOTE     :  主要是用在图形的属性设置时的笔宽设置
// CREATE   :  FNST)handwolf  2004-4-21
// UPDATE   :  
//          : 
//////////////////////////////////////////////////////////////////////
#include "stdafx.h"
#include "LineComboBox.h"
//################################################################
CLineComboBox::CLineComboBox()
{	
	//当前鼠标是否在对象上
	m_nMouseState = 0;
	m_nLineLength = 45;
	m_nItemHeight = 20;
	m_nMargin=2;
}
//################################################################
CLineComboBox::~CLineComboBox()
{
	while(!m_LineWidthList.IsEmpty()){
		delete m_LineWidthList.RemoveHead();
	}	
}
//################################################################
BOOL CLineComboBox::Create(DWORD dwStyle, const RECT& rect, CWnd* pParentWnd, UINT nID)
{
	DWORD dw = dwStyle;
	//dw |= CBS_OWNERDRAWVARIABLE;
	
	if( !CComboBox::Create(dw, rect, pParentWnd, nID) )
		return false;
	CFont * font = CFont::FromHandle((HFONT)::GetStockObject(DEFAULT_GUI_FONT));
	SetFont(font);
	return true;
}
//################################################################
void CLineComboBox::Init()
{	
	for(int i = 0; i <= 6; i++)
	{
		LPBSCBITEM lpItem = new BSCBITEM;
		CString strText;
		strText.Format("   %d",i+1);
		lpItem->lpCaption=strText;
		lpItem->iIndex = AddString(strText);
		lpItem->nLineWidth = i+1;	
		
		if(m_LineWidthList.IsEmpty())
			m_LineWidthList.AddHead(lpItem);
		else
			m_LineWidthList.AddTail(lpItem);		
	}
}
//################################################################
IMPLEMENT_DYNCREATE(CLineComboBox, CComboBox)
BEGIN_MESSAGE_MAP(CLineComboBox, CComboBox)
	//{{AFX_MSG_MAP(CLineComboBox)
	ON_WM_ERASEBKGND()
	ON_WM_PAINT()
	ON_WM_MOUSEMOVE()
	//}}AFX_MSG_MAP
END_MESSAGE_MAP()
//################################################################
BOOL CLineComboBox::OnEraseBkgnd(CDC* pDC) 
{	
	ASSERT(pDC->GetSafeHdc());
	return false;
}
//################################################################
void CLineComboBox::OnPaint() 
{
	CPaintDC dc(this); 
	OnCBPaint(&dc);
}
//################################################################
void CLineComboBox::OnCBPaint(CDC* pDC)
{
	ASSERT(pDC->GetSafeHdc());
	
	//绘制客户区
	CDC dMemDC;
	dMemDC.CreateCompatibleDC(pDC);
	dMemDC.SetMapMode(pDC->GetMapMode());	
	//画动作
	CBitmap mNewBmp;
	RECT rc;
	GetClientRect(&rc);
	mNewBmp.CreateCompatibleBitmap(pDC, rc.right - rc.left, rc.bottom - rc.top);
	CBitmap* pOldBmp = dMemDC.SelectObject(&mNewBmp);
	//子类可以以friend方式来访问父类的protected成员变量和函数
	CWnd::DefWindowProc(WM_PAINT, (WPARAM)dMemDC.m_hDC, 0);
	
	pDC->BitBlt(rc.left, rc.top, rc.right - rc.left, rc.bottom - rc.top, &dMemDC,
		rc.left ,rc.top, SRCCOPY);
	
	//恢复
	dMemDC.SelectObject(pOldBmp);
	pOldBmp->DeleteObject();
	dMemDC.DeleteDC();
	GetWindowRect(&rc);
	ScreenToClient(&rc);
	pDC->DrawEdge(&rc, (m_nMouseState ? BDR_RAISEDINNER : BDR_SUNKENINNER), BF_RECT);
}
//################################################################
void CLineComboBox::MeasureItem(LPMEASUREITEMSTRUCT lpMeasureItemStruct) 
{	
	lpMeasureItemStruct->itemHeight = m_nItemHeight;
}
//################################################################
void CLineComboBox::DrawItem(LPDRAWITEMSTRUCT lpDIS) 
{	
	ASSERT(lpDIS->CtlType == ODT_COMBOBOX);	
    
	//画笔
	CDC* pDC = CDC::FromHandle(lpDIS->hDC);
	ASSERT(pDC->GetSafeHdc());	
	//绘制区
	RECT rc = lpDIS->rcItem;
	CRect rcLine(rc), rcTxt(rc);
	
	//当前的Item索引号
	LPBSCBITEM lpItem = GetItem(lpDIS->itemID);	
	if(lpItem != NULL){		
		BOOL bSelected =lpDIS->itemState & ODS_SELECTED;			
		pDC->FillSolidRect(&rcLine,RGB(255,255,255));//察除以前的画面
		//如果选中	
		if(bSelected){
			pDC->FillSolidRect(&rcLine,RGB(0,255,255));
		}
		//画Line
		CPen pen,*pOldPen;
		pen.CreatePen(PS_SOLID,lpItem->nLineWidth,RGB(0,0,255));
		pOldPen=pDC->SelectObject(&pen);       
		rcLine.right=rcLine.left+m_nLineLength;
		rcLine.DeflateRect(m_nMargin,m_nMargin);	
		
		pDC->MoveTo(rcLine.left,(rcLine.top+rcLine.bottom)/2);
		pDC->LineTo(rcLine.right,(rcLine.top+rcLine.bottom)/2);		
		pDC->SelectObject(pOldPen);
        
	//	pDC->DrawEdge(&rcLine, BDR_RAISEDINNER, BF_RECT);
		//开始画文字
		int nOldBkMode = pDC->SetBkMode(TRANSPARENT);
		pDC->SetTextColor(RGB(0, 0, 0));		
		rcTxt.left = rcLine.right + m_nMargin;
	//	rcTxt.top = rcLine.top;		
		pDC->DrawText(lpItem->lpCaption,&rcTxt,DT_VCENTER|DT_END_ELLIPSIS|DT_NOCLIP|DT_SINGLELINE);		
		pDC->SetBkMode(nOldBkMode);
	}
}
//################################################################
LPBSCBITEM CLineComboBox::GetItem(int iIndex)
{
	//当前的Item索引号
	POSITION pos = m_LineWidthList.FindIndex(iIndex);
	if(pos)
	{
		LPBSCBITEM lpItem = m_LineWidthList.GetAt(pos);		
		ASSERT(lpItem);
		return lpItem;
	}
	else
		return (LPBSCBITEM)NULL;
}
//################################################################
void CLineComboBox::OnMouseMove(UINT nFlags, CPoint point) 
{
	CComboBox::OnMouseMove(nFlags, point);
}
int CLineComboBox::GetCurLineWidth()
{
	int nSel=GetCurSel();
	POSITION pos = m_LineWidthList.FindIndex(nSel);
	if(pos)
	{
		LPBSCBITEM lpItem = m_LineWidthList.GetAt(pos);		
		ASSERT(lpItem);
		return lpItem->nLineWidth;
	}
	else
		return 0;
}

						