LinkButton 链接样式的按钮

#pragma once

// LinkButton.h : header file
//

/////////////////////////////////////////////////////////////////////////////
// CLinkButton window

class CLinkButton : public CButton
{
// Construction
public:
CLinkButton();

// Attributes
public:

// Operations
public:

// Overrides
// ClassWizard generated virtual function overrides
//{{AFX_VIRTUAL(CLinkButton)
public:
virtual void DrawItem(LPDRAWITEMSTRUCT lpDrawItemStruct);
//}}AFX_VIRTUAL

// Implementation
public:
CFont fUnderline;
HCURSOR hHand;
bool bLBtnDown;
bool bHighlight;

COLORREF m_clrNormal;
COLORREF m_clrHight;

virtual ~CLinkButton();

// Generated message map functions
protected:
//{{AFX_MSG(CLinkButton)
afx_msg void OnMouseMove(UINT nFlags, CPoint point);
afx_msg BOOL OnSetCursor(CWnd* pWnd, UINT nHitTest, UINT message);
afx_msg void OnTimer(UINT nIDEvent);
afx_msg int OnCreate(LPCREATESTRUCT lpCreateStruct);
afx_msg void OnLButtonUp(UINT nFlags, CPoint point);
afx_msg void OnLButtonDown(UINT nFlags, CPoint point);
afx_msg BOOL OnEraseBkgnd(CDC* pDC);
//}}AFX_MSG

DECLARE_MESSAGE_MAP()
};

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

// LinkButton.cpp : implementation file
//

#include "stdafx.h"
#include "LinkButton.h"

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

/////////////////////////////////////////////////////////////////////////////
// CLinkButton

CLinkButton::CLinkButton()
{
bHighlight = bLBtnDown = false;
hHand = LoadCursor(NULL, IDC_HAND);

m_clrNormal = RGB(0,0,255);
m_clrHight  = RGB(255,0,0);
}

CLinkButton::~CLinkButton()
{
if (fUnderline.GetSafeHandle()) fUnderline.DeleteObject();
}

BEGIN_MESSAGE_MAP(CLinkButton, CButton)
//{{AFX_MSG_MAP(CLinkButton)
ON_WM_MOUSEMOVE()
ON_WM_SETCURSOR()
ON_WM_TIMER()
ON_WM_CREATE()
ON_WM_LBUTTONUP()
ON_WM_LBUTTONDOWN()
ON_WM_ERASEBKGND()
//}}AFX_MSG_MAP
END_MESSAGE_MAP()

/////////////////////////////////////////////////////////////////////////////
// CLinkButton message handlers

void CLinkButton::DrawItem(LPDRAWITEMSTRUCT lpDrawItemStruct)
{
// 获取一个CDC指针
CDC* pDC = CDC::FromHandle(lpDrawItemStruct->hDC);

//定义按钮区域并初始化
CRect rect(lpDrawItemStruct->rcItem);

//设置背景模式
COLORREF oc = pDC->GetTextColor();
int iObk = pDC->SetBkMode(TRANSPARENT);

//初始化按钮状态
UINT state = lpDrawItemStruct->itemState;

CFont * pOldFont = NULL;

int iYOffset = 0, iXOffset = 0;

CString strText;
GetWindowText(strText);

rect.top  += iYOffset;
rect.left += iXOffset;

if (state & ODS_DISABLED)
{  
  //按钮置灰（DISABLED）
  CBrush grayBrush;
  grayBrush.CreateSolidBrush (GetSysColor (COLOR_GRAYTEXT));
  CSize sz = pDC->GetTextExtent(strText);
  int x = rect.left + (rect.Width() - sz.cx)/2;
  int y = rect.top + (rect.Height() - sz.cy)/2;
  rect.top  += 2;
  rect.left += 2;
  pDC->SetTextColor(GetSysColor(COLOR_3DHIGHLIGHT));
  pDC->DrawText(strText, rect, DT_CENTER | DT_VCENTER | DT_SINGLELINE);
  rect.top  -= 2;
  rect.left -= 2;
  pDC->SetTextColor(GetSysColor(COLOR_GRAYTEXT));

  //加下画线（也可以用其他字体）
  if (fUnderline.GetSafeHandle() == NULL)
  {
   CFont * pFont = GetFont();
   ASSERT(pFont);
   LOGFONT lf;
   pFont->GetLogFont(&lf);
   lf.lfUnderline = TRUE;
   fUnderline.CreateFontIndirect(&lf);  
  }

  pOldFont = pDC->SelectObject(&fUnderline);

  pDC->DrawText(strText, rect, DT_CENTER | DT_VCENTER | DT_SINGLELINE);
}
else
{
  if (bHighlight || (state & ODS_FOCUS))//光标在按钮上
  {
   //字体颜色
   pDC->SetTextColor(m_clrHight);
  }
  else
  {
   //字体颜色
   pDC->SetTextColor(m_clrNormal);   
  }

  //加下画线（也可以用其他字体）
  if (fUnderline.GetSafeHandle() == NULL)
  {
   CFont * pFont = GetFont();
   ASSERT(pFont);
   LOGFONT lf;
   pFont->GetLogFont(&lf);
   lf.lfUnderline = TRUE;
   fUnderline.CreateFontIndirect(&lf);  
  }

  pOldFont = pDC->SelectObject(&fUnderline);

  pDC->DrawText(strText, rect, DT_CENTER | DT_VCENTER | DT_SINGLELINE);
  if (pOldFont) pDC->SelectObject(pOldFont);
}
}

void CLinkButton::OnMouseMove(UINT nFlags, CPoint point)
{
//设置一个定时器
SetTimer(1,10,NULL);
CButton::OnMouseMove(nFlags, point);
}

BOOL CLinkButton::OnSetCursor(CWnd* pWnd, UINT nHitTest, UINT message)
{
if (bHighlight)
{
  ::SetCursor(hHand);
  return true;
}
return CButton::OnSetCursor(pWnd, nHitTest, message);
}

void CLinkButton::OnTimer(UINT nIDEvent)
{
static bool pPainted = false;
POINT pt;
GetCursorPos(&pt);
CRect rect;
GetWindowRect (rect);
if (bLBtnDown) 
{  
  KillTimer (1);
  if (pPainted) InvalidateRect (NULL);  
  pPainted = FALSE;  
  return; 
}

if (!rect.PtInRect (pt)) 
{  
  bHighlight = false;
  KillTimer (1);

  if (pPainted)   
   InvalidateRect(NULL);

  pPainted = false;
  return; 
}
else
{
  bHighlight = true;
  if (!pPainted)
  {
   pPainted = true;
   InvalidateRect(NULL);
  }
}

CButton::OnTimer(nIDEvent);
}

int CLinkButton::OnCreate(LPCREATESTRUCT lpCreateStruct)
{
if (CButton::OnCreate(lpCreateStruct) == -1)
  return -1;
CFont * pFont = GetFont();
ASSERT(pFont);

LOGFONT lf;
pFont->GetLogFont(&lf);
lf.lfUnderline = TRUE;

fUnderline.CreateFontIndirect(&lf);
return 0;
}

void CLinkButton::OnLButtonUp(UINT nFlags, CPoint point)
{
bLBtnDown = false;
if (bHighlight) 
{
  bHighlight = false;
  InvalidateRect(NULL);
}
CButton::OnLButtonUp(nFlags, point);
}

void CLinkButton::OnLButtonDown(UINT nFlags, CPoint point)
{
bLBtnDown = true;
CButton::OnLButtonDown(nFlags, point);
}

BOOL CLinkButton::OnEraseBkgnd(CDC* pDC)
{
COLORREF cr = GetSysColor(COLOR_3DFACE);
int r = GetRValue(cr);
int g = GetGValue(cr);
int b = GetBValue(cr);
if (r > 1) r -= 2;
if (g > 1) g -= 2;
if (r < 3 && g < 3 && b < 253) b += 2;
COLORREF cr1 = RGB(r,g,b);
CRect rc;
GetClientRect(rc);
pDC->FillSolidRect(rc, cr1);
return CButton::OnEraseBkgnd(pDC);
}