MFC错误

[clarence_cpp]

使用opengl显示数字，得到以下错误，不知道如何解决。
代码如下

字体定义：

#include "stdafx.h"
#include "glFont.h"
#include <gl\gl.h>
#include <gl\glu.h>
#include "gl\glaux.h"
#include <atlstr.h>

CGlFont::CGlFont()
{
	m_hFont=NULL;
	InitFont("宋体",10);
	m_X = 0;
	m_Y = 0;
	m_dHeight = 0;
	m_fExtrusion = 0.1f;
	m_rotateTheta = 0.0;
	m_iDisplayList = 0;
	m_red =255;
	m_blue = 255;
	m_green = 255;
}

CGlFont::~CGlFont()
{

}

LOGFONT CGlFont::GetLogFont()
{
	LOGFONT lf;
	GetObject(m_hFont,sizeof(LOGFONT),&lf);
	return lf;
}

void CGlFont::DeleteFont()
{
	if(m_hFont)
	{
		DeleteObject(m_hFont);
		m_hFont=NULL;
	}
}

bool CGlFont::InitFont(LOGFONT &lf)
{
	DeleteFont();
	m_hFont=CreateFontIndirect(&lf);
	if( m_hFont )return true;
	else return false;;
}

bool CGlFont::InitFont(char *fontName, int height)
{
	DeleteFont();
	m_hFont = CreateFont(
		-height,         //< lfHeight 字体高度
		0,          //< lfWidth 字体宽度 
		0,          //< lfEscapement 字体的旋转角度 Angle Of Escapement 
		0,          //< lfOrientation 字体底线的旋转角度Orientation Angle 
		FW_THIN,        //< lfWeight 字体的重量 
		FALSE,         //< lfItalic 是否使用斜体 
		FALSE,         //< lfUnderline 是否使用下划线 
		FALSE,         //< lfStrikeOut 是否使用删除线 
		DEFAULT_CHARSET,       //< lfCharSet 设置字符集 
		OUT_TT_PRECIS,       //< lfOutPrecision 输出精度 
		CLIP_DEFAULT_PRECIS,     //< lfClipPrecision 裁剪精度 
		ANTIALIASED_QUALITY,     //< lfQuality 输出质量 
		FF_DONTCARE|DEFAULT_PITCH,    //< lfPitchAndFamily Family And Pitch 
		fontName);        //< lfFaceName 字体名称 
	if(m_hFont)return true;
	else return false;
}

void CGlFont::Draw2DText(char *string)
{
	if(strlen(string)<=0)return;

	//HDC hDC=wglGetCurrentDC();
	HDC hDC = ::CreateCompatibleDC(NULL);

	HFONT hOldFont=NULL;
	hOldFont=(HFONT)SelectObject(hDC,m_hFont);
	if(!hOldFont)
	{
		return;
	}

	glRasterPos2f(m_X, m_Y);

	DWORD dwChar;
	int ListNum;
	for(size_t i=0;i<strlen((char *)string);i++)
	{
		if(IsDBCSLeadByte(string[i]))
		{
			dwChar=((unsigned char)string[i])*0x100+(unsigned char)string[i+1];
			i++;
		}
		else
		{
			dwChar=string[i];
		}
		ListNum=glGenLists(1);
		wglUseFontBitmaps(hDC,dwChar,1,ListNum);
		glCallList(ListNum);
		glDeleteLists(ListNum,1);
	}
	SelectObject(hDC,hOldFont);
	::DeleteDC(hDC);
}
map<UINT,FontDesc>  CGlFont::m_sglFontList;

void CGlFont::Draw3DText(const char *string)
{
	if(strlen(string)<=0)
		return;

	GLYPHMETRICSFLOAT pgmf[1];
	HDC hDC=wglGetCurrentDC();

 //设置当前字体
	HFONT hOldFont=NULL;
	hOldFont=(HFONT)SelectObject(hDC,m_hFont);
	if(!hOldFont)
	{
		return;
	}
	DWORD dwChar;
	int ListNum;

	int iNum=strlen((char *)string);
	m_iDisplayList=glGenLists(1);

	glPushMatrix();

	for(size_t i=0;i<strlen((char *)string);i++)
	{
		if(IsDBCSLeadByte(string[i]))//是否为中文
		{
			dwChar=((unsigned char)string[i])*0x100+(unsigned char)string[i+1];
			i++;
		}
		else
		{
			dwChar=string[i];
		}
	//不同的文字在文字描述表中只出现一次，如“我是中国中国”，重复的中和国只出现一次，这样大大提高了速度
		if (m_sglFontList.find(dwChar) == m_sglFontList.end())
		{
			GLuint newID  = glGenLists(1);
			wglUseFontOutlines(hDC,dwChar,1,newID,0.0,m_fExtrusion,WGL_FONT_LINES,pgmf);
			FontDesc  font;
			font.flyfloat = pgmf[0];
			font.iList = newID;
			m_sglFontList[dwChar] = font;
		}
	}
	glPopMatrix();
	SelectObject(hDC,hOldFont);

	//生成操作列表
	glNewList(m_iDisplayList, GL_COMPILE);
	glPushMatrix();
	glTranslated(m_X,m_Y,0);
	glScaled(m_dHeight,m_dHeight,1);
	glRotated(m_rotateTheta,0,0,1); 
	for(size_t i=0;i<strlen((char *)string);i++)
	{

		if(IsDBCSLeadByte(string[i]))
		{
			dwChar=((unsigned char)string[i])*0x100+(unsigned char)string[i+1];
			i++;
		}
		else
		{
			dwChar=string[i];
		}
		glCallList(m_sglFontList[dwChar].iList);

	}
	glPopMatrix();
	glEndList();

	//执行操作表中的内容
	glPushMatrix();
	glColor3ub((GLbyte)m_red,(GLbyte)m_green,(GLbyte)m_blue);
	glCallList(m_iDisplayList);
	glPopMatrix();
}

void CGlFont::SetColor(int r, int g, int b)
{
	m_red = r;
	m_green = g;
	m_blue = b;
}

使用

CGlFont glFont;
	int Font_Height = 10;
	glFont.InitFont(_T("Times new roma"),Font_Height);

	int count = 0;
	for(float x = -length_area/2-10; x <= length_area/2+80; x +=20)
	{
		float y = -5.0f;
		if (count%5==0)
		{
			glFont.m_X = (x-9);
			glFont.m_Y = (y-20);
			glFont.m_dHeight =0.1;
			glFont.SetColor(255,255,255);
			int temp =count * 20;
			CString s;
			s.Format("%d",temp);
			glFont.Draw2DText(s.GetBuffer());
		}
		count++;
	}

	//Y坐标轴系数
	count =0;
	for (float y = 0; y <= 100; y +=5)
	{
		float x = -length_area/2-15;

		if (count%5==0)
		{
			glFont.InitFont(_T("Times new roma"),Font_Height);
			glFont.m_X = x-190;
			glFont.m_Y = y;
			glFont.m_dHeight =0.1;
			glFont.SetColor(255,255,255);
			float  temp = (maxHeight*height_scale/4)*(count/5);

			CString s;
			s.Format("%.4f",temp);
			glFont.Draw2DText(s.GetBuffer());

		}
		count++;
	}

[caewow]

从报错的图片来看，程序试图读取一段内存时，出现了 访问违规 的问题，而且，这个问题极有可能是由于某一个 DC句柄 为空导致的，建议楼主在程序获得 DC句柄 的地方都加上断言，防止句柄为空。

ASSERT( hDC != NULL );