创建WINDOWS XP样式的ActiveX按钮

 



使用MFC向导来创建一个ActiveX控件是一件非常简单的事。这篇文章里我会向大家阐述了怎样在VC++里面创建一个类似WINDOWS XP样式的ActiveX按钮。
选择MFC ActiveX控件向导来创建一个新的工程，并命名为“XpButtonEx”。在ActiveX控件向导里有两步。在第一个对话框中选择一个控件，不要运行时间许可，源文件注释和帮助文件。在第二个对话框中选择“Activates When Visible”, 在Insert Object对话框中选择“Available”，还有一个About对话框。当向导询问：“Which window class, if any, should this control subclass?”时选择“BUTTON”。点完成。向导会建立大约19个文件，有三个类：CxpButtonExApp, CxpButtonExCtrl和CxpButtonExPropPage。
现在打开类向导，并确认当前选定的是CxpButtonExCtrl。为WM_CREATE, WM_LBUTTONDOWN, WM_LBUTTONUP,和WM_MOUSEMOVE添加消息映射。在Class观察表中右击CxpButtonExCtrl，然后添加虚函数：PreSubclassWindow。在PreSubclassWindow函数的COleControl::PreSubclassWindow()添加语句：ModifyStyle(0, BS_OWNERDRAW|BS_NOTIFY)。现在打开XpButtonEx.h，添加下列成员变量和函数：public:<?xml:namespace prefix = o ns = "urn:schemas-microsoft-com:office:office" />CPen *pBoundryPen;CPen *pInsideBoundryPenLeft;CPen *pInsideBoundryPenTop;CPen *pInsideBoundryPenRight;CPen *pInsideBoundryPenBottom;CPen *pOldPen;CBrush *pFillActive;CBrush *pFillInactive;CBrush *pOldBrush;BOOL m_bOverControl;void DoGradientFill(CDC *pDC, CRect rect);void DrawInsideBorder(CDC *pDC, CRect rect);

打开XpButtonEx.cpp。在构造函数CXpButtonExCtrl()添加下列代码：m_bOverControl = FALSE;  pBoundryPen = new CPen(PS_INSIDEFRAME|PS_SOLID,1,RGB(0,0,0));  pInsideBoundryPenLeft = new CPen(PS_INSIDEFRAME|      PS_SOLID,3,RGB(250,196,88));  pInsideBoundryPenRight = new CPen(PS_INSIDEFRAME|      PS_SOLID,3,RGB(251,202,106));  pInsideBoundryPenTop = new CPen(PS_INSIDEFRAME|      PS_SOLID,2,RGB(252,210,121));  pInsideBoundryPenBottom = new CPen(PS_INSIDEFRAME|      PS_SOLID,2,RGB(229,151,0));  pFillActive = new CBrush(RGB(222,223,236));  pFillInactive = new CBrush(RGB(222,223,236));

在析构函数~CXpButtonExCtrl()里删除对象：pBoundryPen->DeleteObject();  pFillActive->DeleteObject();  pFillInactive->DeleteObject();  pOldPen->DeleteObject();  pOldBrush->DeleteObject();  pInsideBoundryPenLeft->DeleteObject();  pInsideBoundryPenRight->DeleteObject();  pInsideBoundryPenBottom->DeleteObject();  pInsideBoundryPenTop->DeleteObject();

在XpButtonCtl.cpp中添加下列函数：void CXpButtonExCtrl::DoGradientFill(CDC *pDC, CRect rect){    CBrush* pBrush[64];    for (int i=0; i<64; i++)      pBrush[i] = new CBrush(RGB(253-(i/2),                             253-(i/3),                              253-(i/4)));    int nWidth = (rect.right) - (rect.left);    int nHeight = (rect.bottom) - (rect.top);    CRect rct;     for (i=rect.top; i < nHeight+2; i++)  {        rct.SetRect (rect.left, i, nWidth+2, i + 1);        pDC->FillRect (&rct, pBrush[(i * 63) / nHeight]);    }     for (i=0; i<64; i++)        delete pBrush[i]; }void CXpButtonExCtrl::DrawInsideBorder(CDC *pDC,CRect rect){  pOldPen = pDC->SelectObject(pInsideBoundryPenLeft);  pDC->MoveTo(rect.left,rect.bottom-3);  pDC->LineTo(rect.left,rect.top+2);  pDC->SelectObject(pInsideBoundryPenRight);  pDC->MoveTo(rect.right-1,rect.bottom-3);  pDC->LineTo(rect.right-1,rect.top+2);  pDC->SelectObject(pInsideBoundryPenTop);  pDC->MoveTo(rect.left+2,rect.top);  pDC->LineTo(rect.right-2,rect.top);  pDC->SelectObject(pInsideBoundryPenBottom);  pDC->MoveTo(rect.left+2,rect.bottom);  pDC->LineTo(rect.right-2,rect.bottom);  pDC->SelectObject(pOldPen);}

现在回到OnOcmCommand()，并在返回0值以前添加下列switch：...switch(wNotifyCode){  case BN_CLICKED:  // // The click event should be fired                    // when the button is clicked.          click事件应该在按钮按下时被激活          FireClick();   break;}

我们使用Boolean变量m_bOverControll来跟踪鼠标位置。当鼠标在按钮上时，按钮接收到WM_MOUSEMOVE。将OnMouseMove的代码作如下改动：void CXpButtonExCtrl::OnMouseMove(UINT nFlags, CPoint point){  // TODO: Add your message handler code  // here and/or call default.   COleControl::OnMouseMove(nFlags, point);  if(!m_bOverControl)  {   m_bOverControl = TRUE;   Invalidate(FALSE);   TRACKMOUSEEVENT tm;   tm.cbSize = sizeof(tm);   tm.dwFlags = TME_LEAVE;   tm.hwndTrack = this->m_hWnd;   ::_TrackMouseEvent(&tm);  }}现在，为了检测鼠标什么时候离开按钮，我们必须手动添加下列消息句柄。在XpButtonExCtl.h中添加：LRESULT OnMouseLeave(WPARAM, LPARAM);在XpButtonExCtl.cpp中添加：ON_MESSAGE(WM_MOUSELEAVE, OnMouseLeave)。在XpButtonExCtl.cpp中添加函数：LRESULT CXpButtonExCtrl::OnMouseLeave(WPARAM, LPARAM){   m_bOverControl = FALSE;  Invalidate(FALSE);  return 0;}现在，为了画出按钮，我们需要手动为OCM_DRAWITEM消息添加句柄。在 XpButtonExCtl.h 里添加LRESULT OnOcmDrawItem(WPARAM wParam, LPARAM lParam)。在XpButtonExCtl.cpp里添加add ON_MESSAGE(OCM_DRAWITEM, OnOcmDrawItem)。在XpButtonEx.cpp里添加函数OnOcmDrawItem：LRESULT CXpButtonExCtrl::OnOcmDrawItem(WPARAM wParam,                                       LPARAM lParam){  UINT nIDCtl = (UINT) wParam;  LPDRAWITEMSTRUCT lpDrawItemStruct =                             (LPDRAWITEMSTRUCT) lParam;  CDC* pDC   = CDC::FromHandle(lpDrawItemStruct->hDC);  CRect rect = lpDrawItemStruct->rcItem;  UINT state = lpDrawItemStruct->itemState;     // 画出控件的边缘   CPoint pt;  pt.x = 10;  pt.y = 10;      pOldPen = pDC->SelectObject(pBoundryPen);    if (state & ODS_SELECTED)       pDC->RoundRect(rect,pt);    else       pDC->RoundRect(rect,pt);    pDC->SelectObject(pOldPen);    //按照按钮边缘的大小缩小画图区域    rect.DeflateRect( CSize(GetSystemMetrics(SM_CXEDGE),                      GetSystemMetrics(SM_CYEDGE)));    //如果必要填充内部颜色   if (m_bOverControl)   {      pOldBrush = pDC->SelectObject(pFillActive);      DoGradientFill(pDC,rect);      DrawInsideBorder(pDC,rect);   }   else   {      pOldBrush = pDC->SelectObject(pFillInactive);      DoGradientFill(pDC,rect);   }   pDC->SelectObject(pOldBrush);          //画出文本     if (!m_title.IsEmpty())    {        CSize Extent = pDC->GetTextExtent(m_title/*strText*/);        CPoint pt( rect.CenterPoint().x - Extent.cx/2,         rect.CenterPoint().y - Extent.cy/2 );         if (state & ODS_SELECTED)             pt.Offset(1,1);         int nMode = pDC->SetBkMode(TRANSPARENT);        CFont *pOldFont = SelectStockFont( pDC );         if (state & ODS_DISABLED)            pDC->DrawState( pt,                            Extent,                            m_title,                            DSS_DISABLED,                            TRUE,                            0,                             (HBRUSH)NULL);        else            pDC->TextOut(pt.x, pt.y, m_title);pDC->SelectObject(pOldFont);        pDC->SetBkMode(nMode);    }  return 0;}现在我们将对我们的ActiveX Control添加两个属性。一个是Tile，另一个是Font。打开类向导，选择自动控制（Automation）标签。确认所选类是CxpButtonEx。点击“Add Property”按钮。在Add Property对话框中，给它一个外部名称（如“title”）并选择类型为Cstring。接受默认的变量和函数。点击OK关闭类向导对话框。。在XpButtonExCtl.cpp里的DoPropExchange函数TODO注释后面添加下列语句：PX_String( pPX, _T("title"), m_title, _T("Caption"));现在到Resourses观察标签下打开对话框模板IDD_PROPPAGE_XPBUTTONEX，删除TODO:...声明。增加一个编辑框IDC_TITLE，现在打开类向导，选择成员变量标签。选择类CxpButtonExPropPage，选择IDC_TITLE然后点“Add Variable”。在成员变量对话框中，给一个成员变量赋名（如m_title）， Category - Value, Variable Type – Cstring。给Optional Property一个名字（如title）。点击OK关闭类向导对话框。现在我们可以添加Font的一般属性。打开类向导选择自动控制标签。确认所选类名是CxpButtonEx。点击“Add Property”按钮。在组合框中选择外部名称（如font）。点击OK关闭类向导对话框。现在我们为font设置一个属性页。这真的很简单，因为我们可以使用先前写好的属性页。打开XpButtonExCtl.cpp，找到如下代码：BEGIN_PROPPAGEIDS(CDierollCtrl, 1)  PROPPAGEID(CDierollPropPage::guid)END_PROPPAGEIDS(CdierollCtrl在这里改变计数到2，添加另一个PROPPAGEID。新写的代码象这样：BEGIN_PROPPAGEIDS(CDierollCtrl, 2)  PROPPAGEID(CDierollPropPage::guid)  PROPPAGEID(CLSID_CFontPropPage)END_PROPPAGEIDS(CDierollCtrl)现在我们的控件终于完成了。到另一个ActiveX测试器中去测试它吧！