WTL 自定义 Button类-自绘

WTL 自绘Button类，支持按钮三种形态，正常模式，hover模式，鼠标按下模式，支持png图片。使用方法很简单：

MyButton* pButton = new MyButton;
   pButton->SetBtnBmp(strBtnNormal,strBtnHover,strBtnDown);
   pButton->Create(m_hWnd,rt,NULL,WS_CHILD|WS_VISIBLE);
   pButton->SetBtnID(nID);//该ID是用来处理WM_COMMAND 命令的，即单机左键命令

#pragma  once

#pragma comment(lib, "gdiplus.lib")

static ULONG_PTR s_gdiplusToken2=0;

enum

{

	btn_state_normal = 0,

	btn_state_over   = 1,

	btn_state_down  = 2

};

class MyButton:public CWindowImpl<MyButton>

{

public:

	MyButton()

	{

		GdiplusStartupInput gdiplusStartupInput;

		GdiplusStartup(&s_gdiplusToken2, &gdiplusStartupInput, NULL);

		m_nState = btn_state_normal;

		m_bBtnDown = false;

	}

	~MyButton()

	{

		GdiplusShutdown(s_gdiplusToken2);

	}

protected:

	BEGIN_MSG_MAP(MyButton)

		MESSAGE_HANDLER(WM_DESTROY, OnDestroy)

		MESSAGE_HANDLER(WM_PAINT,OnPaint)

		MESSAGE_HANDLER(WM_MOUSEMOVE,OnMouseMove)

		MESSAGE_HANDLER(WM_MOUSELEAVE,OnMouseLeave)

		MESSAGE_HANDLER(WM_LBUTTONDOWN,OnLButtonDown)

		MESSAGE_HANDLER(WM_LBUTTONUP,OnLButtonUp)

		MESSAGE_HANDLER(WM_CREATE,OnCreate)

		MESSAGE_HANDLER(WM_ERASEBKGND,OnEraseBkgnd)

	END_MSG_MAP()

	LRESULT OnCreate(UINT /*uMsg*/, WPARAM /*wParam*/, LPARAM /*lParam*/, BOOL& /*bHandled*/)

	{

		CRect winRect;

		GetWindowRect(winRect);

		SetWindowPos(HWND_TOPMOST,winRect,SWP_SHOWWINDOW);

		return TRUE;

	}

	LRESULT OnEraseBkgnd(UINT /*uMsg*/, WPARAM /*wParam*/, LPARAM /*lParam*/, BOOL& /*bHandled*/)

	{

		return TRUE;

	}

	HBITMAP GetBitmapFromFile( LPCWSTR pFile )

	{

		std::auto_ptr<Bitmap> pBmp(new Bitmap(pFile));

		if(!pBmp.get())

			return NULL;

		HBITMAP hBmp = NULL;

		Color backColor = Color(255,0,0,0);

		if(Ok!=pBmp->GetHBITMAP(backColor,&hBmp))

			return NULL;

		return hBmp;

	}

	void SetBtnBmp(CString strBtnNormal,CString strBtnHover,CString strBtnDown)

	{

		m_btmNormal.Attach(GetBitmapFromFile(strBtnNormal));

		m_btmOver.Attach(GetBitmapFromFile(strBtnHover));

		m_btmDown.Attach(GetBitmapFromFile(strBtnDown));

	}

	BOOL  DrawBmp( HDC hdc, CRect rect, HBITMAP hBitmap )

	{

		BITMAP bm;

		GetObject(hBitmap,sizeof(bm),(VOID*)&bm);

		INT nWidth = bm.bmWidth;

		INT nHeight = bm.bmHeight;

		CDC memdc;

		memdc.CreateCompatibleDC(hdc);

		CBitmap bitmap;

		bitmap.CreateCompatibleBitmap(hdc,nWidth,nHeight);

		memdc.SelectBitmap(hBitmap);

		BLENDFUNCTION bf = {AC_SRC_OVER,0,255,1};

		return ::AlphaBlend(hdc,rect.left,rect.top,nWidth,nHeight,memdc,0,0,nWidth,nHeight,bf);

		//::StretchBlt(hdc,rect.left,rect.top,rect.right-rect.left,rect.bottom-rect.top,

		//		comDC,0,0,bmp.bmWidth,bmp.bmHeight,SRCCOPY );

	}

		LRESULT OnPaint(UINT /*uMsg*/, WPARAM /*wParam*/, LPARAM /*lParam*/, BOOL& /*bHandled*/)

	{

		CPaintDC dc(m_hWnd);

		CRect rect;

		GetClientRect(&rect);

		switch(m_nState)

		{

		case btn_state_over:

			DrawBmp(dc,rect,m_btmOver);

			break;

		case btn_state_down:

			DrawBmp(dc,rect,m_btmDown);

			break;

		default://case = btn_state_normal

			DrawBmp(dc,rect,m_btmNormal);

			break;

		}

		dc.SetBkMode(TRANSPARENT);

		dc.SetTextColor(RGB(240,250,240));

		dc.DrawText(m_strText,m_strText.GetLength(),&rect,DT_CENTER);

		return TRUE;

	}

	LRESULT OnMouseMove(UINT /*uMsg*/, WPARAM /*wParam*/, LPARAM /*lParam*/, BOOL& /*bHandled*/)

	{

		if(!m_bBtnDown)

		{

			m_nState = btn_state_over;

			InvalidateRect(NULL);

			TRACKMOUSEEVENT   t_MouseEvent;

			t_MouseEvent.cbSize       =     sizeof(TRACKMOUSEEVENT);

			t_MouseEvent.dwFlags      =     TME_LEAVE|TME_HOVER;

			t_MouseEvent.hwndTrack    =     m_hWnd;

			t_MouseEvent.dwHoverTime  =     30;

			::_TrackMouseEvent(&t_MouseEvent);

		}

		return TRUE;

	}

	LRESULT OnMouseLeave(UINT /*uMsg*/, WPARAM /*wParam*/, LPARAM /*lParam*/, BOOL& /*bHandled*/)

	{

		m_nState = btn_state_normal;

		m_bBtnDown = false;

		InvalidateRect(NULL);

		return TRUE;

	}

	LRESULT OnLButtonUp(UINT /*uMsg*/, WPARAM /*wParam*/, LPARAM /*lParam*/, BOOL& /*bHandled*/)

	{

		m_nState = btn_state_normal;

		m_bBtnDown  = false;

		InvalidateRect(NULL);

		::PostMessage(GetParent(),WM_COMMAND,m_nBtnID,NULL);

		return TRUE;

	}

	LRESULT OnLButtonDown(UINT /*uMsg*/, WPARAM /*wParam*/, LPARAM /*lParam*/, BOOL& /*bHandled*/)

	{

		m_bBtnDown = true;

		m_nState = btn_state_down;

		InvalidateRect(NULL);

		return TRUE;

	}

	LRESULT OnDestroy(UINT /*uMsg*/, WPARAM /*wParam*/, LPARAM /*lParam*/, BOOL& /*bHandled*/)

	{

		return TRUE;

	}

	void SetBtnText(CString strText)

	{

		m_strText = strText;

	}

	void SetBtnID(int nID)

	{

		m_nBtnID = nID;

	}

private:

	CBitmap m_btmNormal;

	CBitmap m_btmOver;

	CBitmap m_btmDown;

	int m_nState;

	bool m_bBtnDown;

	CString m_strText;

	INT	    m_nBtnID;

};