MFC 之 CButton 控件重绘（GDI篇）

最近在为公司用MFC做产品界面。因为是小公司，所以也没有现成的界面库，必须自己一点一点写。自己在网上收集了点资料，就写了几个类型的button类，以供以后使用。

目前为止，做了三种类型的按钮,分别是：

1.一般情况使用的，比较常用的button类CNormalBtn;

2.特殊一点的，类似拥有菜单功能的button类CMenuBtn(和CNormal的区别是按钮selected后的状态不会随着鼠标的离开而消失);

3.静态按钮，用来呈现log等图片之类的button类CStatic,该类不会响应鼠标事件。

对于1,2种按钮，用的图片模式是：

（png格式，一幅图里有四副小图，依次表示NoFoucs,Mousemove,
buttondown, Disable四种状态）；

对于3类按钮，用的图片模式是：

（png格式）

下面贴代码：

基类代码（BaseBtn.h）

#ifndef __BASEBTN_H__
#define __BASEBTN_H__

#include "stdafx.h"
#include <atlimage.h>

#if _MSC_VER > 1000
#pragma once
#endif

class CBaseBtn : public CButton
{
public:
CBaseBtn();
~CBaseBtn();

public:
virtual BOOL Create(LPCTSTR lpszClassName, LPCTSTR lpszWindowName, DWORD dwStyle, const RECT& rect, CWnd* pParentWnd, UINT nID, CCreateContext* pContext = NULL);
virtual void DrawItem(LPDRAWITEMSTRUCT lpDrawItemStruct);
virtual void SetFont(CFont* pFont, BOOL bRedraw = TRUE);
virtual void SetWindowText(LPCTSTR lpszString);

public:
void Init(UINT uImageID);
void SetBtnTextColor(COLORREF clr);

protected:
afx_msg BOOL OnEraseBkgnd(CDC* pDC);

DECLARE_MESSAGE_MAP()

protected:
int			m_nCtrlState;

CImage		m_Image;
int			m_nSrcWidth;
int			m_nSrcHeight;

private:
CString		m_strBtnText;
CFont*		m_pFont;
COLORREF	m_clr;
};

#endif

基类代码（BaseBtn.cpp）

#include "stdafx.h"
#include "BaseBtn.h"
#include "Public.h"

#ifdef _DEBUG
#define new DEBUG_NEW
#undef THIS_FILE
static char THIS_FILE[] = __FILE__;
#endif

CBaseBtn::CBaseBtn()
{
m_pFont = new CFont;
VERIFY(m_pFont->CreateFont(15, 0, 0, 0, FW_BOLD, FALSE, FALSE, 0, ANSI_CHARSET, OUT_DEFAULT_PRECIS,
CLIP_DEFAULT_PRECIS,DEFAULT_QUALITY, DEFAULT_PITCH | FF_SWISS, _T("Tahoma")));

m_strBtnText = L"";
m_clr = RGB(0, 0, 0);
}

CBaseBtn::~CBaseBtn()
{
if (!m_Image.IsNull())
m_Image.Destroy();

if (m_pFont != NULL)
{
m_pFont->DeleteObject();

delete m_pFont;
m_pFont = NULL;
}
}

BEGIN_MESSAGE_MAP(CBaseBtn, CButton)
ON_WM_ERASEBKGND()
END_MESSAGE_MAP()

void CBaseBtn::Init(UINT uImageID)
{
SetButtonStyle(BS_OWNERDRAW);

LoadPicture(m_Image, uImageID);
m_nSrcWidth = m_Image.GetWidth();
m_nSrcHeight = m_Image.GetHeight();

SetWindowPos(NULL, 0, 0, m_nSrcWidth/4, m_nSrcHeight, SWP_NOMOVE|SWP_NOACTIVATE);

if (IsWindowEnabled())
m_nCtrlState = CTRL_NOFOCUS;
else
m_nCtrlState = CTRL_DISABLE;
}

void CBaseBtn::SetFont(CFont* pFont, BOOL bRedraw)
{
m_pFont = pFont;

if(bRedraw)
Invalidate();
}

void CBaseBtn::SetWindowText(LPCTSTR lpszString)
{
m_strBtnText = lpszString;
Invalidate();
}

void CBaseBtn::SetBtnTextColor(COLORREF clr)
{
m_clr = clr;
Invalidate();
}

BOOL CBaseBtn::Create(LPCTSTR lpszClassName, LPCTSTR lpszWindowName, DWORD dwStyle, const RECT& rect, CWnd* pParentWnd, UINT nID, CCreateContext* pContext)
{
return CWnd::Create(lpszClassName, lpszWindowName, dwStyle, rect, pParentWnd, nID, pContext);
}

void CBaseBtn::DrawItem(LPDRAWITEMSTRUCT lpDrawItemStruct)
{
if (m_Image.IsNull())
return ;

CRect buttonRect;
GetClientRect(buttonRect);

CDC* pDC = CDC::FromHandle(lpDrawItemStruct->hDC);		//按钮控件DC

CDC dcMem;
dcMem.CreateCompatibleDC(pDC);

CBitmap memBitmap;
memBitmap.CreateCompatibleBitmap(pDC, buttonRect.Width(), buttonRect.Height());
dcMem.SelectObject(memBitmap);

dcMem.FillSolidRect(buttonRect, RGB(255,0,255));	//设置画布颜色

CRect rcSrc = CRect(0,0,0,0);
switch(m_nCtrlState)
{
case CTRL_NOFOCUS:
{
rcSrc = CRect(0, 0, m_nSrcWidth/4, m_nSrcHeight);
}
break;

case CTRL_FOCUS:
{
rcSrc = CRect(m_nSrcWidth/4, 0, m_nSrcWidth/4 * 2, m_nSrcHeight);
}
break;
case CTRL_SELECTED:
{
rcSrc = CRect(m_nSrcWidth/4 * 2, 0, m_nSrcWidth/4 * 3, m_nSrcHeight);
}
break;

case CTRL_DISABLE:
{
rcSrc = CRect(m_nSrcWidth/4 * 3, 0, m_nSrcWidth, m_nSrcHeight);
}
break;

default:
break;
}
m_Image.Draw(dcMem.m_hDC, buttonRect, rcSrc);

dcMem.SetBkMode(TRANSPARENT);
dcMem.SetTextColor(m_clr);
CFont* pOldFont = dcMem.SelectObject(m_pFont);
DrawText(dcMem.m_hDC, m_strBtnText, -1, buttonRect, DT_CENTER|DT_SINGLELINE|DT_VCENTER);
dcMem.SelectObject(pOldFont);

pDC->BitBlt(0, 0, buttonRect.Width(), buttonRect.Height(), &dcMem, 0, 0, SRCCOPY);
memBitmap.DeleteObject();
}

BOOL CBaseBtn::OnEraseBkgnd(CDC* pDC)
{
return TRUE;
}

第一类button(NormalBtn.h)

#ifndef __NORMALBTN_H__
#define __NORMALBTN_H__

#include "BaseBtn.h"

class CNormalBtn : public CBaseBtn
{
public:
CNormalBtn();
~CNormalBtn();

protected:
afx_msg void OnMouseMove(UINT nFlags, CPoint point);
afx_msg void OnLButtonDown(UINT nFlags, CPoint point);
afx_msg void OnLButtonUp(UINT nFlags, CPoint point);
afx_msg LRESULT OnMouseLeave(WPARAM, LPARAM);
afx_msg LRESULT OnMouseHover(WPARAM, LPARAM);

DECLARE_MESSAGE_MAP()

private:
BOOL   m_bTracking;						// 捕获设置标记

};

#endif

第一类button(NormalBtn. cpp)

#include "stdafx.h"
#include "NormalBtn.h"
#include "Public.h"

#ifdef _DEBUG
#define new DEBUG_NEW
#undef THIS_FILE
static char THIS_FILE[] = __FILE__;
#endif

CNormalBtn::CNormalBtn()
:m_bTracking(FALSE)
{

}

CNormalBtn::~CNormalBtn()
{

}

BEGIN_MESSAGE_MAP(CNormalBtn, CBaseBtn)
ON_WM_MOUSEMOVE()
ON_WM_LBUTTONDOWN()
ON_WM_LBUTTONUP()
ON_MESSAGE(WM_MOUSELEAVE,OnMouseLeave)
ON_MESSAGE(WM_MOUSEHOVER,OnMouseHover)
END_MESSAGE_MAP()

void CNormalBtn::OnMouseMove(UINT nFlags, CPoint point)
{
if (!m_bTracking)
{
TRACKMOUSEEVENT tme;
tme.cbSize = sizeof(tme);
tme.hwndTrack = m_hWnd;
tme.dwFlags = TME_LEAVE|TME_HOVER;
tme.dwHoverTime = 1;
m_bTracking = _TrackMouseEvent(&tme);
}

CBaseBtn::OnMouseMove(nFlags, point);
}
LRESULT CNormalBtn::OnMouseHover(WPARAM wParam,LPARAM lParam)
{
if (m_nCtrlState == CTRL_NOFOCUS)
{
m_nCtrlState = CTRL_FOCUS;
Invalidate();
}

m_bTracking = FALSE;
return 0;
}

LRESULT CNormalBtn::OnMouseLeave(WPARAM wParam,LPARAM   lParam)
{
if(m_nCtrlState != CTRL_NOFOCUS)
{
m_nCtrlState = CTRL_NOFOCUS;
Invalidate();
}

m_bTracking = FALSE;
return 0;
}

void CNormalBtn::OnLButtonDown(UINT nFlags, CPoint point)
{
if(m_nCtrlState == CTRL_FOCUS)
{
m_nCtrlState = CTRL_SELECTED;
Invalidate();
}

CBaseBtn::OnLButtonDown(nFlags, point);
}

void CNormalBtn::OnLButtonUp(UINT nFlags, CPoint point)
{
if(m_nCtrlState == CTRL_SELECTED)
{
m_nCtrlState = CTRL_FOCUS;
Invalidate();
}
CBaseBtn::OnLButtonUp(nFlags, point);
}

第二类按钮（CMenu.h）

#ifndef __MENUBTN_H__
#define __MENUBTN_H__

#include "BaseBtn.h"

class CMenuBtn : public CBaseBtn
{
public:
CMenuBtn();
~CMenuBtn();

public:
BOOL GetMenuOn()	{ return m_bMenuOn;	}
void SetMenuOn(BOOL bMenuOn);

protected:
afx_msg void OnMouseMove(UINT nFlags, CPoint point);
afx_msg void OnLButtonDown(UINT nFlags, CPoint point);
afx_msg LRESULT OnMouseLeave(WPARAM, LPARAM);
afx_msg LRESULT OnMouseHover(WPARAM, LPARAM);

DECLARE_MESSAGE_MAP()

private:
BOOL   m_bTracking;						// 捕获设置标记
BOOL   m_bMenuOn;						// 该菜单按钮是否被选中

};

#endif

第二类按钮（CButton.cpp）

#include "stdafx.h"
#include "MenuBtn.h"
#include "Public.h"

#ifdef _DEBUG
#define new DEBUG_NEW
#undef THIS_FILE
static char THIS_FILE[] = __FILE__;
#endif

CMenuBtn::CMenuBtn()
:m_bTracking(FALSE)
,m_bMenuOn(FALSE)
{

}

CMenuBtn::~CMenuBtn()
{

}

BEGIN_MESSAGE_MAP(CMenuBtn, CBaseBtn)
ON_WM_MOUSEMOVE()
ON_WM_LBUTTONDOWN()
ON_MESSAGE(WM_MOUSELEAVE,OnMouseLeave)
ON_MESSAGE(WM_MOUSEHOVER,OnMouseHover)
END_MESSAGE_MAP()

void CMenuBtn::OnMouseMove(UINT nFlags, CPoint point)
{
if (!m_bTracking)
{
TRACKMOUSEEVENT tme;
tme.cbSize = sizeof(tme);
tme.hwndTrack = m_hWnd;
tme.dwFlags = TME_LEAVE|TME_HOVER;
tme.dwHoverTime = 1;
m_bTracking = _TrackMouseEvent(&tme);
}

CButton::OnMouseMove(nFlags, point);
}

void CMenuBtn::OnLButtonDown(UINT nFlags, CPoint point)
{
if(m_nCtrlState != CTRL_SELECTED)
{
m_nCtrlState = CTRL_SELECTED;
m_bMenuOn = TRUE;
Invalidate();
}

CButton::OnLButtonDown(nFlags, point);
}

LRESULT CMenuBtn::OnMouseLeave(WPARAM     wParam,LPARAM   lParam)
{
if(m_bMenuOn)
{
m_nCtrlState = CTRL_SELECTED;
Invalidate();
}
else
{
m_nCtrlState = CTRL_NOFOCUS;
Invalidate();
}

m_bTracking = FALSE;
return 0;
}

LRESULT CMenuBtn::OnMouseHover(WPARAM wParam,LPARAM lParam)
{
if (m_nCtrlState != CTRL_FOCUS)
{
m_nCtrlState = CTRL_FOCUS;
Invalidate();
}

m_bTracking = FALSE;
return 0;
}

void CMenuBtn::SetMenuOn(BOOL bMenuOn)
{
m_bMenuOn = bMenuOn;
Invalidate();
}

第三类按钮（CStaticBtn.h）

#ifndef __STATICBTN_H__
#define __STATICBTN_H__

#include "BaseBtn.h"

class CStaticBtn : public CBaseBtn
{
public:
CStaticBtn();
~CStaticBtn();

public:
virtual void Init(UINT uImageID);
virtual void DrawItem(LPDRAWITEMSTRUCT lpDrawItemStruct);
};

#endif

第三类按钮（CStaticBtn.cpp）

#include "stdafx.h"
#include "StaticBtn.h"
#include "Public.h"

CStaticBtn::CStaticBtn()
{

}

CStaticBtn::~CStaticBtn()
{

}

void CStaticBtn::Init(UINT uImageID)
{
SetButtonStyle(BS_OWNERDRAW);

LoadPicture(m_Image, uImageID);
m_nSrcWidth = m_Image.GetWidth();
m_nSrcHeight = m_Image.GetHeight();

SetWindowPos(NULL, 0, 0, m_nSrcWidth, m_nSrcHeight, SWP_NOMOVE|SWP_NOACTIVATE);
}

void CStaticBtn::DrawItem(LPDRAWITEMSTRUCT lpDrawItemStruct)
{
if (m_Image.IsNull())
return;

CRect rcBtutton;
GetClientRect(rcBtutton);

CDC* pDC = CDC::FromHandle(lpDrawItemStruct->hDC);

CRect rcSrc = CRect(0, 0, m_nSrcWidth, m_nSrcHeight);
m_Image.Draw(pDC->m_hDC, rcBtutton, rcSrc);
}

使用方法：

CNoraml m_NorBtn;

m_NorBtn.Init(UNIT);

因为NormalBtn和MenuBtn需要相应鼠标事件，有图片切换，为了更好的图片切换效果使用双缓冲绘图。双缓冲绘图需要先创建一张画布（CBaseBtn::DrawItem（）函数）

CBitmap memBitmap;
memBitmap.CreateCompatibleBitmap(pDC, buttonRect.Width(), buttonRect.Height());
dcMem.SelectObject(memBitmap);
dcMem.FillSolidRect(buttonRect, RGB(255,0,255));	//设置画布颜色

所以虽然用了虽然PNG图片有透明属性，但是画布无法设置透明属性，最后的结果是虽然PNG图片背景透明了，因为画布的存在，无法做出一个不规程的按钮出来。

而StaticBtn使用的是单缓冲，没有画布的存在，利用PNG图片的透明属性，可以做出一个不规则的按钮。但是单缓冲绘图对于图片的切换效果不好，所以只用来做一个不响应鼠标消息的静态按钮。未来有空我将会写《MFC 之 CButton 控件重绘（GDI+篇）》利用GDI+绘图来解决这个问题。

完整的项目工程下载地址：http://download.csdn.net/detail/yuzhenxiong0823/7167827