MFC第二十六天 CRgn类简介与开发、封装CMemoryDC类并应用开发

CRgn类简介与开发

CRgn类简介

CRgn类是MFC（Microsoft Foundation Classes）中的一个图形区域类。该类用于创建和操作图形区域，可以表示各种形状的区域，如矩形、椭圆、多边形等。

class CRgn : public CGdiObject
{
public:static CRgn* PASCAL FromHandle(HRGN hRgn);operator HRGN() const;// 封装的特点是没有使用Overload重载函数，结构体就是XXXIndirectCRgn();
//创建矩形区域BOOL CreateRectRgn(int x1, int y1, int x2, int y2);BOOL CreateRectRgnIndirect(LPCRECT lpRect);
//创建圆形区域BOOL CreateEllipticRgn(int x1, int y1, int x2, int y2);BOOL CreateEllipticRgnIndirect(LPCRECT lpRect);
//多边形BOOL CreatePolygonRgn(LPPOINT lpPoints, int nCount, int nMode);BOOL CreatePolyPolygonRgn(LPPOINT lpPoints, LPINT lpPolyCounts,int nCount, int nPolyFillMode);
//圆角矩形BOOL CreateRoundRectRgn(int x1, int y1, int x2, int y2, int x3, int y3);
//BOOL CreateFromPath(CDC* pDC);BOOL CreateFromData(const XFORM* lpXForm, int nCount,const RGNDATA* pRgnData);// 修改矩形void SetRectRgn(int x1, int y1, int x2, int y2);void SetRectRgn(LPCRECT lpRect);
//混合int CombineRgn(const CRgn* pRgn1, const CRgn* pRgn2, int nCombineMode);int CopyRgn(const CRgn* pRgnSrc);
//判断区域完全一样BOOL EqualRgn(const CRgn* pRgn) const;
//判断一个点是否在区域内BOOL PtInRegion(int x, int y) const;BOOL PtInRegion(POINT point) const;
//保持形状不变偏移int OffsetRgn(int x, int y);int OffsetRgn(POINT point);
//框图int GetRgnBox(LPRECT lpRect) const;BOOL RectInRegion(LPCRECT lpRect) const;int GetRegionData(LPRGNDATA lpRgnData, int nCount) const;// Implementationvirtual ~CRgn();
};

CRgn类的混合功能：
int CombineRgn(    CRgn* pRgn1,    CRgn* pRgn2,    int nCombineMode  );RGN_AND   交集
RGN_COPY   拷贝
RGN_DIFF 不同
RGN_OR   并集
RGN_XOR   异或

CRgn类区域管理开发

CRgnDlg.h

#pragma once
class CCRgnDlg : public CDialogEx
{
// 构造CDC m_dc;CRect m_rect;
}

CRgnDlg.cpp

BOOL CCRgnDlg::OnInitDialog(){CDialogEx::OnInitDialog();CBitmap bmp;bmp.LoadBitmap(IDB_LOGO);BITMAP bm;bmp.GetBitmap(&bm);m_rect.SetRect(0,0, bm.bmWidth,bm.bmHeight );m_dc.CreateCompatibleDC(NULL);m_dc.SelectObject(&bmp);SetIcon(m_hIcon, TRUE);			// 设置大图标SetIcon(m_hIcon, FALSE);		// 设置小图标return TRUE;  // 除非将焦点设置到控件，否则返回 TRUE
}

//透明 一个去掉不要的区域进行显示  透明度（半透明）
void CCRgnDlg::OnPaint(){CPaintDC dc(this); // 用于绘制的设备上下文	CRgn rgn;  //输出区域管理  dc.FillSolidRect(CRect(10, 10, 700, 400), RGB(0, 255, 0)); //填充了一块背景区域CRect rect;rect = m_rect;rect.OffsetRect(50, 0);//rgn.CreateEllipticRgn(0, 0, m_rect.right, m_rect.bottom); //圆形区域管理rgn.CreateEllipticRgn(rect.left,rect.top, rect.right, rect.bottom);dc.SelectObject(&rgn);//dc.BitBlt(0, 0, m_rect.right, m_rect.bottom, &m_dc, 0, 0, SRCCOPY); //对图片的空白区域操作dc.BitBlt(50, 0, m_rect.Width(), m_rect.Height(), &m_dc, 0, 0, SRCCOPY);
}

CircleRgnDlg.h

#pragma once
class CCircleRgnDlg : public CDialogEx
{
// 构造CDC m_dc;CRect m_rect;
public:afx_msg LRESULT OnNcHitTest(CPoint point);
};

CircleRgnDlg.cpp

BOOL CCircleRgnDlg::OnInitDialog(){CDialogEx::OnInitDialog();CBitmap bmp;bmp.LoadBitmap(IDB_LOGO);BITMAP bm;bmp.GetBitmap(&bm);m_rect.SetRect(0, 0, bm.bmWidth, bm.bmHeight);SetWindowPos(NULL, 0, 0, m_rect.Width(), m_rect.Height(), SWP_NOMOVE | SWP_NOZORDER);m_dc.CreateCompatibleDC(NULL);m_dc.SelectObject(&bmp);CRgn rgn;rgn.CreateEllipticRgnIndirect(m_rect);SetWindowRgn(rgn, FALSE);return TRUE;  // 除非将焦点设置到控件，否则返回 TRUE
}

void CCircleRgnDlg::OnPaint()
{CPaintDC dc(this); // 用于绘制的设备上下文dc.BitBlt(0, 0, m_rect.right, m_rect.bottom, &m_dc, 0, 0, SRCCOPY);
}LRESULT CCircleRgnDlg::OnNcHitTest(CPoint point)
{return HTCAPTION;
}

CRgn类区域管理与不规则形状的选取

CCircleRgnDlg.h

class CCircleRgnDlg : public CDialogEx
{
// 构造CDC m_dc;CRect m_rect;
public:afx_msg LRESULT OnNcHitTest(CPoint point);afx_msg void OnLButtonDown(UINT nFlags, CPoint point);
};

CCircleRgnDlg.cpp

BOOL CCircleRgnDlg::OnInitDialog(){CDialogEx::OnInitDialog();CBitmap bmp;bmp.LoadBitmap(IDB_LOGO);BITMAP bm;bmp.GetBitmap(&bm);m_rect.SetRect(0, 0, bm.bmWidth, bm.bmHeight);SetWindowPos(NULL, 0, 0, m_rect.Width(), m_rect.Height(), SWP_NOMOVE | SWP_NOZORDER);m_dc.CreateCompatibleDC(NULL);m_dc.SelectObject(&bmp);/*CRgn rgn;rgn.CreateEllipticRgnIndirect(m_rect);SetWindowRgn(rgn, FALSE);*/return TRUE;  // 除非将焦点设置到控件，否则返回 TRUE
}

//CRgn r, r1, r2;
//r.CreateEllipticRgn(20, 20, 500, 400);
//dc.SelectObject(&r);
//dc.BitBlt(0, 0, m_rect.right, m_rect.bottom, &m_dc, 0, 0, SRCCOPY);
//
//POINT pts[] = { {482,192},{568,302},{322,538},{123,357},{251,192},{360,320} };
//r1.CreatePolygonRgn(pts, _countof(pts), ALTERNATE);
//
//r2.CreateRectRgn(0, 0, 0, 0);
//
//r2.CombineRgn(&r, &r1, RGN_AND);
//r2.CombineRgn(&r, &r1, RGN_XOR);
//dc.SelectObject(&r2);
//dc.BitBlt(0, 0, m_rect.right, m_rect.bottom, &m_dc, 0, 0, SRCCOPY);

void CCircleRgnDlg::OnPaint()
{CPaintDC dc(this); // 用于绘制的设备上下文CRgn r,r1;r.CreateEllipticRgn(20, 20, 500, 400);POINT pts[] = {{482,192},{568,302},{322,538},{123,357},{251,192},{360,320}};r1.CreatePolygonRgn(pts, _countof(pts), ALTERNATE);r.CombineRgn(&r, &r1, RGN_XOR);dc.SelectObject(&r);CRect rect;r.GetRgnBox(rect);//框图要考虑如何恢复到之前图dc.BitBlt(0, 0, m_rect.right, m_rect.bottom, &m_dc, 0, 0, SRCCOPY); 

	BITMAP bm;dc.GetCurrentBitmap()->GetBitmap(&bm); //获取当前选中的位图对象，并将其信息存储在bm结构中。r.DeleteObject();r.CreateRectRgn(0, 0, bm.bmWidth, bm.bmHeight);dc.SelectObject(&r);dc.SelectStockObject(NULL_BRUSH); //绘制图形时使用的画刷对象设置为无画刷，即不填充图形dc.Rectangle(rect);
}

void CCircleRgnDlg::OnLButtonDown(UINT nFlags, CPoint point){ CRgn r, r1, r2;r.CreateEllipticRgn(20, 20, 500, 400);POINT pts[] = { {482,192},{568,302},{322,538},{123,357},{251,192},{360,320} };r1.CreatePolygonRgn(pts, _countof(pts), ALTERNATE);r.CombineRgn(&r, &r1, RGN_XOR);if (r.PtInRegion(point)){AfxMessageBox(_T("你选择了"));}CDialogEx::OnLButtonDown(nFlags, point);
}

封装CMemoryDC类并应用开发

CMemoryDC.h

/* 内存DC类简介：
1、BOOL LoadBitmap(UINT nBitmapID,CDC* pDC = NULL)	 从资源中按照，按位图ID加载位图
2、BOOL LoadFile(LPCTSTR sFile, CDC* pDC = NULL)	从exe外部加载图片（调用LoadImage）
3、BOOL Create(int cx, int cy, CDC* pDC = NULL)		创建空白位图（默认是全黑）4、总共有4种构造函数，包含以上3种还有空构造：
CMemoryDC(UINT nBitmapID)//从资源按照位图编号来加载
CMemoryDC(LPCTSTR sFile, CDC* pDC = NULL)//从exe外部加载
CMemoryDC(int cx, int cy, CDC* pDC=NULL)//指定高宽创建空白位图5、void MakeRgn(CRgn& r,COLORREF col)				生成透明区域
6、int GetWidth() const		int GetHeight() const	方便地获取图片高宽：
7、透明显示：BitTrans和StrecthTrans		*/

#pragma once
#include "resource.h"
class CMemoryDC :public CDC{CSize m_size;
public:CMemoryDC();int GetWidth() const{return m_size.cx;}int GetHeight() const{return m_size.cy;}CSize GetSize() const	{return m_size;}

	void BitTrans(int nXDest,		// 目标起点Xint nYDest,		// 目标起点Yint nWidthDest,	// 目标宽度int nHeightDest,// 目标高度CDC* pDC,		// 目标DCint nXSrc,		// 来源起点Xint nYSrc,		// 来源起点YCOLORREF crTrans// 透明色){CMemoryDC dcImage(nWidthDest, nHeightDest, pDC);//临时DCCBitmap bmpMask;bmpMask.CreateBitmap(nWidthDest, nHeightDest, 1, 1, NULL);       // 创建单色掩码位图CDC dcMask;//掩码DC dcMask.CreateCompatibleDC(pDC);dcMask.SelectObject(bmpMask);//将载入位图的内存DC中的位图，拷贝到临时DC中dcImage.BitBlt(0, 0, nWidthDest, nHeightDest, this, nXSrc, nYSrc, SRCCOPY);// 设置临时DC的透明色dcImage.SetBkColor(crTrans);//掩码DC的透明区域为白色其它区域为黑色dcMask.BitBlt(0, 0, nWidthDest, nHeightDest, &dcImage, 0, 0, SRCCOPY);//临时DC透明区域为黑色，其它区域保持不变dcImage.SetBkColor(RGB(0, 0, 0));dcImage.SetTextColor(RGB(255, 255, 255));dcImage.BitBlt(0, 0, nWidthDest, nHeightDest, &dcMask, 0, 0, SRCAND);// 目标DC透明部分保持屏幕不变，其它部分变成黑色pDC->SetBkColor(RGB(255, 255, 255));pDC->SetTextColor(RGB(0, 0, 0));pDC->BitBlt(nXDest, nYDest, nWidthDest, nHeightDest, &dcMask, 0, 0, SRCAND);pDC->BitBlt(nXDest, nYDest, nWidthDest, nHeightDest, &dcImage, 0, 0, SRCPAINT);}void StretchTrans(int nXDest,			// 目标起点Xint nYDest,			// 目标起点Yint nWidthDest,     // 目标宽度int nHeightDest,    // 目标高度CDC* pDC,			// 目标DCint nXSrc,			// 来源起点Xint nYSrc,			// 来源起点Yint nWidthSrc,		// 来源宽度int nHeightSrc,		// 来源高度COLORREF crTrans	// 透明色){CMemoryDC dcImage(nWidthDest, nHeightDest, pDC);//临时DCCBitmap bmpMask;// 创建单色掩码位图bmpMask.CreateBitmap(nWidthDest, nHeightDest, 1, 1, NULL);CDC dcMask;dcMask.CreateCompatibleDC(pDC);dcMask.SelectObject(bmpMask);// 将载入位图的内存DC中的位图，拷贝到临时DC中if (nWidthDest == nWidthSrc && nHeightDest == nHeightSrc)dcImage.BitBlt(0, 0, nWidthDest, nHeightDest, this, nXSrc, nYSrc, SRCCOPY);elsedcImage.StretchBlt(0, 0, nWidthDest, nHeightDest,this, nXSrc, nYSrc, nWidthSrc, nHeightSrc, SRCCOPY);// 设置临时DC的透明色dcImage.SetBkColor(crTrans);//掩码DC的透明区域为白色其它区域为黑色dcMask.BitBlt(0, 0, nWidthDest, nHeightDest, &dcImage, 0, 0, SRCCOPY);//临时DC透明区域为黑色，其它区域保持不变dcImage.SetBkColor(RGB(0, 0, 0));dcImage.SetTextColor(RGB(255, 255, 255));dcImage.BitBlt(0, 0, nWidthDest, nHeightDest, &dcMask, 0, 0, SRCAND);// 目标DC透明部分保持屏幕不变，其它部分变成黑色pDC->SetBkColor(RGB(255, 255, 255));pDC->SetTextColor(RGB(0, 0, 0));pDC->BitBlt(nXDest, nYDest, nWidthDest, nHeightDest, &dcMask, 0, 0, SRCAND);pDC->BitBlt(nXDest, nYDest, nWidthDest, nHeightDest, &dcImage, 0, 0, SRCPAINT);}

	BOOL Create(int cx, int cy, CDC* pDc = NULL){	//创建空位图if (!CreateCompatibleDC(NULL))return FALSE;CBitmap bmp;if (pDc)	{if (!bmp.CreateCompatibleBitmap(pDc, cx, cy)) {DeleteDC();return FALSE;		}}else{if (!bmp.CreateCompatibleBitmap(&CClientDC(NULL), cx, cy)){DeleteDC();return FALSE;	}}this->SelectObject(&bmp);m_size.SetSize(cx, cy);return TRUE;	}

	BOOL LoadFile(LPCTSTR sFile, CDC* pDC = NULL){	//加载一张exe外部位图HBITMAP hBitmap = (HBITMAP)LoadImage(NULL, sFile, IMAGE_BITMAP, 0, 0, LR_LOADFROMFILE);if (!hBitmap)return FALSE;	if (!CreateCompatibleDC(NULL)){DeleteObject(hBitmap);return FALSE;}SelectObject(hBitmap);BITMAP bm;GetObject(hBitmap, sizeof(bm), &bm);m_size.SetSize(bm.bmWidth, bm.bmHeight);DeleteObject(hBitmap);return TRUE;}

	BOOL LoadBitmap(UINT nBitmapID, CDC* pDC = NULL)	//加载一张资源位图{if (!CreateCompatibleDC(NULL))return FALSE;CBitmap bmp;if (!bmp.LoadBitmap(nBitmapID)){DeleteDC();return FALSE;}SelectObject(&bmp);BITMAP bm;bmp.GetBitmap(&bm);m_size.SetSize(bm.bmWidth, bm.bmHeight);return TRUE;}

	CMemoryDC(UINT nBitmapID){LoadBitmap(nBitmapID);}CMemoryDC(LPCTSTR sFile,CDC* pDC = NULL){LoadFile(sFile, pDC);}CMemoryDC(int cx,int cy,CDC* pDC=NULL){Create(cx, cy, pDC);}

	void MakeRgn(CRgn& r, COLORREF col){r.CreateRectRgn(0, 0, 0, 0);int i = -1, cx = m_size.cx;int j = -1, cy = m_size.cy;while (++j<cy)	{i = -1;while (++i<cx){if (GetPixel(i, j) != col)	{CRgn r1;r1.CreateRectRgn(i, j, i + 1, j + 1); //1*1像素r.CombineRgn(&r, &r1, RGN_OR);}}}}};

封装CMemoryDC开发游戏透明动画

CFlashDlg.h

#pragma once
#include "CMemoryDC.h"
class CCFlashDlg : public CDialogEx{//二维动画 不停的切换7张图， x y方向不断地移动int m_nIndex{}; //第几张图片CPoint m_pos{}, m_dir{ 5,5 };//m_pos偏移位置 m_dir每次运动5，5enum {Fly_nCount =7}; //图片总数CMemoryDC m_dcBack{_T("./res/back.bmp")}; //背景图片CMemoryDC m_dcFlys[Fly_nCount]; //蝴蝶CRgn m_rs[Fly_nCount]; //取出背景颜色void LoadPictures();public:afx_msg void OnTimer(UINT_PTR nIDEvent);
};

CFlashDlg.cpp

#include "pch.h"
#include "framework.h"
#include "CFlash.h"
#include "CFlashDlg.h"
#include "afxdialogex.h"
void CCFlashDlg::LoadPictures(){int i = -1;CString str;while (++i<_countof(m_dcFlys)){str.Format(_T("./res/%03d.bmp"), i + 1);m_dcFlys[i].LoadFile(str);m_dcFlys[i].MakeRgn(m_rs[i],0x00ff00ff);}
}

BOOL CCFlashDlg::OnInitDialog()
{CDialogEx::OnInitDialog();int cx = GetSystemMetrics(SM_CXSCREEN);int cy = GetSystemMetrics(SM_CYSCREEN);SetWindowPos(NULL, 0, 0, cx/2, cy/2, SWP_NOZORDER);LoadPictures();SetTimer(1, 16, NULL);return TRUE;  // 除非将焦点设置到控件，否则返回 TRUE
}

void CCFlashDlg::OnPaint()
{CPaintDC dc(this); // 用于绘制的设备上下文CRect rect;GetClientRect(rect);dc.SetStretchBltMode(STRETCH_HALFTONE);dc.StretchBlt(0, 0, rect.Width(), rect.Height(), &m_dcBack, 0, 0, m_dcBack.GetWidth(), m_dcBack.GetHeight(), SRCCOPY);CMemoryDC mdc(200,180); //创建默认的黑色if (mdc.GetSafeHdc())dc.BitBlt(200, 150, 200, 180, &mdc, 0, 0, SRCCOPY);//CRgn r;//r.CreateRectRgn(0, 0, 0, 0); //基址//r.CopyRgn(m_rs+m_nIndex);  //往那个跑先复制出来 不要破坏它 形状//r.OffsetRgn(m_pos); //你要输出到那个位置//dc.SelectObject(&r);//dc.BitBlt(m_pos.x, m_pos.y, m_dcFlys->GetWidth(),m_dcFlys->GetHeight(), m_dcFlys + m_nIndex, 0, 0,SRCCOPY);auto pDC = m_dcFlys + m_nIndex; //等价于 :&m_dcFlys[m_nIndex]pDC->BitTrans(m_pos.x, m_pos.y, pDC->GetWidth(), pDC->GetHeight(), &dc, 0, 0, 0xff00ff);if (++m_nIndex >= Fly_nCount)m_nIndex = 0 ;if (m_pos.x + m_dcFlys->GetWidth() > rect.right || m_pos.x < 0)m_dir.x *= -1;if (m_pos.y + m_dcFlys->GetHeight() > rect.bottom || m_pos.y < 0)m_dir.y *= -1;
}

void CCFlashDlg::OnTimer(UINT_PTR nIDEvent)
{m_pos.Offset(m_dir);Invalidate(FALSE);CDialogEx::OnTimer(nIDEvent);
}

封装CMemoryDC开发游戏动画

QQDlg.h

#pragma once
#include "CMemoryDC.h"
class CQQDlg : public CDialogEx
{CPoint m_pos{}, m_dir{ 5,5 }; enum { Fly_nCount = 7 }; //图片总数CMemoryDC m_dcFlys[Fly_nCount]; //蝴蝶CRgn m_rs[Fly_nCount];  int m_nIndex{ 0 };
public:afx_msg void OnTimer(UINT_PTR nIDEvent);
};

QQDlg.cpp

BOOL CQQDlg::OnInitDialog(){CDialogEx::OnInitDialog();int i = -1;while (++i < _countof(m_dcFlys)){m_dcFlys[i].LoadBitmap(IDB_FLY1 + i);m_dcFlys[i].MakeRgn(m_rs[i], 0xff00ff);}SetTimer(1, 16, NULL);CRgn r;r.CreateRectRgn(0, 0, 0, 0);r.CopyRgn(&m_rs[m_nIndex]);SetWindowRgn(r, FALSE);SetWindowPos(NULL, m_pos.x, m_pos.y, m_dcFlys->GetWidth(), m_dcFlys->GetHeight(), SWP_NOZORDER);return TRUE;  // 除非将焦点设置到控件，否则返回 TRUE
}

void CQQDlg::OnPaint()
{CPaintDC dc(this); // 用于绘制的设备上下文int cx = m_dcFlys->GetWidth();int cy = m_dcFlys->GetHeight();dc.BitBlt(0, 0, cx, cy, &m_dcFlys[m_nIndex], 0, 0, SRCCOPY);if (++m_nIndex >= _countof(m_dcFlys)){m_nIndex = 0;}
}

void CQQDlg::OnTimer(UINT_PTR nIDEvent){CDialogEx::OnTimer(nIDEvent);CRgn r;r.CreateRectRgn(0, 0, 0, 0);r.CopyRgn(&m_rs[m_nIndex]);SetWindowRgn(r,FALSE);	 //不这样的话到第七帧的时候就会出来阴影Invalidate(FALSE);SetWindowPos(NULL, m_pos.x, m_pos.y,0,0, SWP_NOZORDER | SWP_NOSIZE);m_pos.Offset(m_dir);int cx = GetSystemMetrics(SM_CXSCREEN);int cy = GetSystemMetrics(SM_CYSCREEN);if (m_pos.x + m_dcFlys->GetWidth() > cx || m_pos.x < 0)m_dir.x *= -1;if (m_pos.y + m_dcFlys->GetHeight() > cy || m_pos.y < 0)m_dir.y *= -1;		}

附录

四大窗口CDC派生类

CPaintDC,CClientDC,CWindowDC,CMemoryDC类
CBitmap对象创建后，默认所有像素都是黑色，0x00000000四个字节一个像素。