MFC 半透明按钮

我就是我 2023-10-18 09:14 77阅读 0赞

**效果展示**  
![在这里插入图片描述][70]  
**实现方法**

1.  给按钮加上BS\_OWNERDRAW样式
2.  重载DrawItem函数,在这里绘制按钮
3.  关键之处就是把父窗口的背景复制到按钮上,实现视觉上的透明
4.  最后通过AlphaBlend实现半透明.

**源码下载:**  
[http://blog.csdn.net/cometnet/article/details/8464693][http_blog.csdn.net_cometnet_article_details_8464693]

**实现源码**

// MyButton.h 
    
    #pragma once 
    
      
      
    // CMyButton 
    
      
    class CMyButton : public CButton
    
    {
         
        DECLARE_DYNAMIC(CMyButton)
    
      
    public:
    
        CMyButton();
    
        virtual ~CMyButton();
    
    public:
    
        void SetBkColor(COLORREF color);
    
        void SetTextColor(COLORREF color);
    
    private:
    
        bool m_bOver;
    
        bool m_bDown;
    
        bool m_bDisable;
    
        bool m_bTracking;
    
        COLORREF m_bkColor;
    
        COLORREF m_textColor;
    
    protected:
    
        DECLARE_MESSAGE_MAP()
    
        virtual BOOL PreCreateWindow(CREATESTRUCT& cs);
    
        virtual void PreSubclassWindow();
    
    public:
    
        virtual void DrawItem(LPDRAWITEMSTRUCT /*lpDrawItemStruct*/);
    
        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 wParam, LPARAM lParam);
    
        afx_msg LRESULT OnMouseHover(WPARAM wParam, LPARAM lParam);
    
        afx_msg void OnEnable(BOOL bEnable);
    
    private:
    
        void ButtonInit();
    
        void DrawButton();
    
        void DrawButton(HDC hDestDC);
    
    };

// MyButton.cpp : 实现文件
    
    // 
      
    #include "stdafx.h"
    
    #include "AlphaButton.h"
    
    #include "MyButton.h"
    
    #include "MainDlg.h"
    
      
    // CMyButton 
    
      
    IMPLEMENT_DYNAMIC(CMyButton, CButton)
    
      
    CMyButton::CMyButton()
    
    {
         
        m_bkColor=0xFFFFFF;
    
        m_textColor=0x000000;
    
    } 
      
    CMyButton::~CMyButton()
    
    {
         
    } 
      
      
    BEGIN_MESSAGE_MAP(CMyButton, CButton)
    
        ON_WM_MOUSEMOVE()
    
        ON_WM_LBUTTONDOWN()
    
        ON_WM_LBUTTONUP()
    
        ON_MESSAGE(WM_MOUSELEAVE, OnMouseLeave)
    
        ON_MESSAGE(WM_MOUSEHOVER, OnMouseHover)
    
        ON_WM_ENABLE()
    
    END_MESSAGE_MAP() 
    
      
      
      
    // CMyButton 消息处理程序
    
      
    void CMyButton::SetBkColor(COLORREF color)
    
    {
         
        m_bkColor=color;
    
    } 
    void CMyButton::SetTextColor(COLORREF color)
    
    {
         
        m_textColor=color;
    
    } 
      
    BOOL CMyButton::PreCreateWindow(CREATESTRUCT& cs)
    
    {
         
        BOOL bRet=CButton::PreCreateWindow(cs);
    
        ButtonInit();
    
        return bRet;
    
    } 
      
    void CMyButton::PreSubclassWindow()
    
    {
         
        CButton::PreSubclassWindow();
    
        ButtonInit();
    
    } 
    void CMyButton::ButtonInit()
    
    {
         
        m_bTracking=false;
    
        m_bOver=m_bDown=m_bDisable=false;
    
        m_bDisable=IsWindowEnabled()?FALSE:TRUE;
    
        ModifyStyle(NULL,BS_OWNERDRAW);
    
    } 
      
    void CMyButton::DrawItem(LPDRAWITEMSTRUCT lpDrawItemStruct)
    
    {
         
      
        DrawButton(lpDrawItemStruct->hDC);
    
    } 
      
    void CMyButton::OnMouseMove(UINT nFlags, CPoint point)
    
    {
         
        if (!m_bTracking)
    
        {
        
    
            m_bOver = TRUE;
    
            TRACKMOUSEEVENT tme;
    
            tme.cbSize = sizeof(tme);
    
            tme.hwndTrack = m_hWnd;
    
            tme.dwFlags = TME_LEAVE | TME_HOVER;
    
            tme.dwHoverTime = 50;
    
            m_bTracking = (bool)_TrackMouseEvent(&tme);
    
        }
    
      
        CButton::OnMouseMove(nFlags, point);
    
    } 
      
    void CMyButton::OnLButtonDown(UINT nFlags, CPoint point)
    
    {
         
        m_bDown=TRUE;
    
      
        CButton::OnLButtonDown(nFlags, point);
    
    } 
      
    void CMyButton::OnLButtonUp(UINT nFlags, CPoint point)
    
    {
         
        m_bDown=FALSE;
    
        CButton::OnLButtonUp(nFlags, point);
    
    } 
    LRESULT CMyButton::OnMouseLeave(WPARAM wParam, LPARAM lParam)
    
    {
         
        m_bOver = FALSE;
    
        m_bTracking = FALSE;
    
        m_bDown=FALSE;
    
        InvalidateRect(NULL, FALSE);
    
        return 0;
    
    } 
      
    LRESULT CMyButton::OnMouseHover(WPARAM wParam, LPARAM lParam)
    
    {
         
        m_bOver = TRUE;
    
        InvalidateRect(NULL);
    
        return 0;
    
    } 
    void CMyButton::DrawButton()
    
    {
         
        HDC hDC=::GetDC(m_hWnd);
    
        DrawButton(hDC);
    
        ::ReleaseDC(m_hWnd,hDC);
    
    } 
    void CMyButton::DrawButton(HDC hDestDC)
    
    {
         
        CRect rc;
    
        GetClientRect(rc);
    
        int nWindth=rc.Width();
    
        int nHeight=rc.Height();
    
        HDC hDC=CreateCompatibleDC(hDestDC);//创建兼容DC,采用双缓冲画出
    
        HDC hMaskDC=CreateCompatibleDC(hDestDC);
    
        HBITMAP hBitmap=CreateCompatibleBitmap(hDestDC,nWindth,nHeight);
    
        HBITMAP hMaskBitmap=CreateCompatibleBitmap(hDestDC,nWindth,nHeight);
    
        HBITMAP hOldBitmap=(HBITMAP)SelectObject(hDC,hBitmap);
    
        HBITMAP hOldMaskBitmap=(HBITMAP)SelectObject(hMaskDC,hMaskBitmap);
    
        SetBkMode(hDC,TRANSPARENT);
    
      
        //把父窗口的背景图复制到按钮的DC上,实现视觉透明----------------
    
        CMainDlg* pParent=(CMainDlg*)GetParent();
    
        CPoint pt(0,0);
    
        MapWindowPoints(pParent,&pt,1);
    
        pParent->m_bkImage.BitBlt(hDC,rc,pt,SRCCOPY);
    
      
      
        //-------------------------------------------------------------
    
        int nAlpha=100;//0--255
    
        int nOffset=0;
    
      
        HBRUSH hbr=CreateSolidBrush(m_bkColor);
    
        FillRect(hMaskDC,&rc,hbr);
    
        DeleteObject(hbr);
    
      
        if(m_bDisable){
        
    
            nAlpha=100;
    
        }else if(m_bDown){
        
    
            nAlpha=180;
    
            nOffset=1;
    
        }else if(m_bOver){
        
    
            nAlpha=150;
    
        }else{
        
    
            nAlpha=100;
    
        }
    
        BLENDFUNCTION blend;
    
        memset( &blend, 0, sizeof( blend) );
    
        blend.BlendOp= AC_SRC_OVER;
    
        blend.SourceConstantAlpha= nAlpha; // 透明度 最大255
    
      
        HRGN hRgn=CreateRoundRectRgn(0,0,nWindth,nHeight,3,3);
    
        SelectClipRgn (hDC,hRgn);
    
        AlphaBlend (hDC,0,0,nWindth,nHeight,hMaskDC, 0,0,nWindth,nHeight,blend);
    
      
        CString strText;
    
        GetWindowText(strText);
    
        if(strText!=_T("")){
        
    
            rc.InflateRect(-2,-2);
    
            rc.OffsetRect(nOffset,nOffset);
    
            HFONT hFont=(HFONT)SendMessage(WM_GETFONT);
    
            if(!hFont)hFont=(HFONT)GetStockObject(DEFAULT_GUI_FONT);
    
            HFONT hOldFont=(HFONT)SelectObject(hDC,hFont);
    
            ::SetTextColor(hDC,m_textColor);
    
            ::DrawText(hDC,strText,-1,&rc,DT_SINGLELINE|DT_CENTER|DT_VCENTER|DT_WORD_ELLIPSIS);
    
            ::SelectObject(hDC,hOldFont);
    
        }
    
        SelectClipRgn (hDC,NULL);
    
        DeleteObject(hRgn);
    
        //复制到控件的DC上------------------------
    
        BitBlt(hDestDC,0,0,nWindth,nHeight,hDC,0,0,SRCCOPY);
    
        //删除资源,释放内存-----------------------
    
        SelectObject(hDC,hOldBitmap);
    
        DeleteObject(hBitmap);
    
        DeleteDC(hDC);
    
        SelectObject(hMaskDC,hOldMaskBitmap);
    
        DeleteObject(hMaskBitmap);
    
        DeleteDC(hMaskDC);
    
      
    } 
    void CMyButton::OnEnable(BOOL bEnable)
    
    {
         
        CButton::OnEnable(bEnable);
    
        m_bDisable=IsWindowEnabled()?FALSE:TRUE;
    
        DrawButton();
    
    }

[70]: https://img-blog.csdn.net/20180926194732324?watermark/2/text/aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L3FxXzE2MTIzMjc5/font/5a6L5L2T/fontsize/400/fill/I0JBQkFCMA==/dissolve/70
[http_blog.csdn.net_cometnet_article_details_8464693]: http://blog.csdn.net/cometnet/article/details/8464693