wxBitmapButton加载png时候去掉系统风格的背景

e:\wxWidgets-2.8.12\src\msw\bmpbuttn.cpp

 

bool wxBitmapButton::MSWOnDraw(WXDRAWITEMSTRUCT *item)
{
#ifndef __WXWINCE__
    long style = GetWindowLong((HWND) GetHWND(), GWL_STYLE);
    if (style & BS_BITMAP)
    {
        // Let default procedure draw the bitmap, which is defined
        // in the Windows resource.
        return false;
    }
#endif

    LPDRAWITEMSTRUCT lpDIS = (LPDRAWITEMSTRUCT) item;
    HDC hDC                = lpDIS->hDC;
    UINT state             = lpDIS->itemState;
    bool isSelected        = (state & ODS_SELECTED) != 0;
    bool autoDraw          = (GetWindowStyleFlag() & wxBU_AUTODRAW) != 0;


    // choose the bitmap to use depending on the button state
    wxBitmap *bitmap;

    if ( isSelected && m_bmpSelected.Ok() )
        bitmap = &m_bmpSelected;
    else if ( m_bmpHover.Ok() && IsMouseInWindow() )
        bitmap = &m_bmpHover;
    else if ((state & ODS_FOCUS) && m_bmpFocus.Ok())
        bitmap = &m_bmpFocus;
    else if ((state & ODS_DISABLED) && m_bmpDisabled.Ok())
        bitmap = &m_bmpDisabled;
    else
        bitmap = &m_bmpNormal;

    if ( !bitmap->Ok() )
        return false;

    // centre the bitmap in the control area
    int x      = lpDIS->rcItem.left;
    int y      = lpDIS->rcItem.top;
    int width  = lpDIS->rcItem.right - x;
    int height = lpDIS->rcItem.bottom - y;
    int wBmp   = bitmap->GetWidth();
    int hBmp   = bitmap->GetHeight();

#if wxUSE_UXTHEME
    if ( autoDraw && wxUxThemeEngine::GetIfActive() )
    {
        MSWDrawXPBackground(this, item);//这里会产生xp风格的背景，可以注释掉，就可以创建png不规则透明按钮了。
        wxUxThemeHandle theme(this, L"BUTTON");

        // calculate content area margins
        // assuming here that each state is the same size
        MARGINS margins;
        wxUxThemeEngine::Get()->GetThemeMargins(theme, NULL,
                                                BP_PUSHBUTTON, PBS_NORMAL,
                                                TMT_CONTENTMARGINS, NULL,
                                                &margins);
        int marginX = margins.cxLeftWidth + 1;
        int marginY = margins.cyTopHeight + 1;
        int x1,y1;

        if ( m_windowStyle & wxBU_LEFT )
        {
            x1 = x + marginX;
        }
        else if ( m_windowStyle & wxBU_RIGHT )
        {
            x1 = x + (width - wBmp) - marginX;
        }
        else
        {
            x1 = x + (width - wBmp) / 2;
        }

        if ( m_windowStyle & wxBU_TOP )
        {
            y1 = y + marginY;
        }
        else if ( m_windowStyle & wxBU_BOTTOM )
        {
            y1 = y + (height - hBmp) - marginY;
        }
        else
        {
            y1 = y + (height - hBmp) / 2;
        }

        // draw the bitmap
        wxDCTemp dst((WXHDC)hDC);
        dst.DrawBitmap(*bitmap, x1, y1, true);

        return true;
    }
#endif // wxUSE_UXTHEME

    int x1,y1;

    if(m_windowStyle & wxBU_LEFT)
        x1 = x + (FOCUS_MARGIN+1);
    else if(m_windowStyle & wxBU_RIGHT)
        x1 = x + (width - wBmp) - (FOCUS_MARGIN+1);
    else
        x1 = x + (width - wBmp) / 2;

    if(m_windowStyle & wxBU_TOP)
        y1 = y + (FOCUS_MARGIN+1);
    else if(m_windowStyle & wxBU_BOTTOM)
        y1 = y + (height - hBmp) - (FOCUS_MARGIN+1);
    else
        y1 = y + (height - hBmp) / 2;

    if ( isSelected && autoDraw )
    {
        x1++;
        y1++;
    }

    // draw the face, if auto-drawing
    if ( autoDraw )
    {
        DrawFace((WXHDC) hDC,
                 lpDIS->rcItem.left, lpDIS->rcItem.top,
                 lpDIS->rcItem.right, lpDIS->rcItem.bottom,
                 isSelected);
    }

    // draw the bitmap
    wxDCTemp dst((WXHDC)hDC);
    dst.DrawBitmap(*bitmap, x1, y1, true);

    // draw focus / disabled state, if auto-drawing
    if ( (state & ODS_DISABLED) && autoDraw )
    {
        DrawButtonDisable((WXHDC) hDC,
                          lpDIS->rcItem.left, lpDIS->rcItem.top,
                          lpDIS->rcItem.right, lpDIS->rcItem.bottom,
                          true);
    }
    else if ( (state & ODS_FOCUS) && autoDraw )
    {
        DrawButtonFocus((WXHDC) hDC,
                        lpDIS->rcItem.left,
                        lpDIS->rcItem.top,
                        lpDIS->rcItem.right,
                        lpDIS->rcItem.bottom,
                        isSelected);
    }

    return true;
}

　　同时button的老爹控件必须重载：EVT_ERASE_BACKGROUND(MyFrame::OnEraseBackground)

new wxBitmapButton(frame,wxID_ANY,wxBitmap(wxT("lastfm-love-focus.png"),wxBITMAP_TYPE_PNG), wxPoint(100,50));

　　

void MyFrame::OnEraseBackground(wxEraseEvent & event)
{
 //初始化DC
    wxClientDC* clientDC = NULL;
    if (!event.GetDC())
        //取得当前DC
        clientDC = new wxClientDC(this);
    wxDC* dc = clientDC ? clientDC : event.GetDC() ;
    //取得用户区域的大小
    wxSize sz = GetClientSize();
    //加载位图
    wxEffects effects;
    effects.TileBitmap(wxRect(0, 0, sz.x, sz.y), *dc, m_imgBack);
    //删除DC
    if (clientDC)
        delete clientDC;
}