ChartCtrl源码剖析之——CChartGrid类

CChartGrid类用来绘制波形区域中的表格，当绘制波形时波形就显示在这些表格上面。它处于该控件的区域，如下图所示：

CChartGrid类的头文件。

#if !defined(AFX_CHARTGRID_H__ECCBEFF4_2365_49CD_A865_F1B4DD8CA138__INCLUDED_)

#define AFX_CHARTGRID_H__ECCBEFF4_2365_49CD_A865_F1B4DD8CA138__INCLUDED_

#if _MSC_VER > 1000

#pragma once

#endif // _MSC_VER > 1000

#include "ChartObject.h"

#include <list>

class CChartAxis;

class CChartGrid : public CChartObject

{

    friend CChartAxis;

public:

    CChartGrid(CChartCtrl* pParent, bool bHoriz);

    virtual ~CChartGrid();

private:

    void Draw(CDC* pDC);

    void AddTick(int Position);

    void ClearTicks();

    std::list<int> m_vecTickPos;

    bool           m_bIsHorizontal;

};

#endif // !defined(AFX_CHARTGRID_H__ECCBEFF4_2365_49CD_A865_F1B4DD8CA138__INCLUDED_)

CChartGrid类的源文件。

#include "stdafx.h"

#include "ChartGrid.h"

#include "ChartAxis.h"

#ifdef _DEBUG

#undef THIS_FILE

static char THIS_FILE[]=__FILE__;

#define new DEBUG_NEW

#endif

using namespace std;

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

// Construction/Destruction

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

CChartGrid::CChartGrid(CChartCtrl* pParent, bool bHoriz)

  : CChartObject(pParent), m_bIsHorizontal(bHoriz), m_vecTickPos()

{

    m_ObjectColor = RGB(,,);

}

CChartGrid::~CChartGrid()

{

}

void CChartGrid::AddTick(int Position)

{

    m_vecTickPos.push_back(Position);

}

void CChartGrid::ClearTicks()

{

    m_vecTickPos.clear();

}

void CChartGrid::Draw(CDC *pDC)

{

    if (!m_bIsVisible)

        return;

    if (!pDC->GetSafeHdc() )

        return;

    CPen* pOldPen;

    CPen NewPen(PS_SOLID,,m_ObjectColor);

    pOldPen = pDC->SelectObject(&NewPen);

    list<int>::iterator iter = m_vecTickPos.begin();

    int ActuPosition = ;

    for (iter; iter!=m_vecTickPos.end(); iter++)

    {

        ActuPosition = *iter;

        if (!m_bIsHorizontal)

        {

            int ActuX = m_ObjectRect.left;

            while (true)

            {

                if (!Clip(ActuX,ActuPosition))

                    break;

                pDC->MoveTo(ActuX,ActuPosition);

                ActuX += ;

                Clip(ActuX,ActuPosition);

                pDC->LineTo(ActuX,ActuPosition);

                ActuX += ;

            }

        }

        else

        {

            int ActuY = m_ObjectRect.bottom;

            while (true)

            {

                if (!Clip(ActuPosition,ActuY))

                    break;

                pDC->MoveTo(ActuPosition,ActuY);

                ActuY -= ;

                Clip(ActuPosition,ActuY);

                pDC->LineTo(ActuPosition,ActuY);

                ActuY -= ;

            }

        }

    }

    pDC->SelectObject(pOldPen);

    DeleteObject(NewPen);

}

这里简单说一下，m_bIsHorizontal用来表示轴的水平与垂直，一开始对这个地方的理解有偏差，当为垂直轴的时候死活没办法理解为什么要累加ActuX的值，因为这明明是横向的嘛。后来意识到绘制的是跟纵轴相关的时候，这个地方就特别好理解了。