VC处理JPG图像实例

//////////////////////////////////////////////////////////////// // MSDN Magazine -- October 2001 // If this code works, it was written by Paul DiLascia. // If not, I don't know who wrote it. // Compiles with Visual C++ 6.0 for Windows 98 and probably Windows 2000 too. // Set tabsize = 3 in your editor. // #include "StdAfx.h" #include "StatLink.h" #ifdef _DEBUG #define new DEBUG_NEW #undef THIS_FILE static char THIS_FILE[] = __FILE__; #endif // hyperlink colors; you can change globally or per control COLORREF CStaticLink::g_colorUnvisited = RGB(0,0,255); // blue COLORREF CStaticLink::g_colorVisited = RGB(128,0,128); // purple // finger-pointing hyperlink cursor HCURSOR CStaticLink::g_hCursorLink = NULL; IMPLEMENT_DYNAMIC(CStaticLink, CStatic) BEGIN_MESSAGE_MAP(CStaticLink, CStatic) ON_WM_NCHITTEST() ON_WM_CTLCOLOR_REFLECT() ON_WM_LBUTTONDOWN() ON_WM_SETCURSOR() END_MESSAGE_MAP() /////////////////// // Constructor sets default colors = blue/purple. // CStaticLink::CStaticLink(LPCTSTR lpText, BOOL bDeleteOnDestroy) { m_link = lpText; // link text (NULL ==> window text) m_color = g_colorUnvisited; // not visited yet m_bDeleteOnDestroy = bDeleteOnDestroy; // delete object with window? m_bNoLink = FALSE; // assume I have a link } ////////////////// // Normally, a static control does not get mouse events unless it has // SS_NOTIFY. This achieves the same effect as SS_NOTIFY, but it's fewer // lines of code and more reliable than turning on SS_NOTIFY in OnCtlColor // because Windows doesn't send WM_CTLCOLOR to bitmap static controls. // UINT CStaticLink::OnNcHitTest(CPoint point) { return HTCLIENT; } ////////////////// // Handle reflected WM_CTLCOLOR to set custom control color. // For a text control, use visited/unvisited colors and underline font. // For non-text controls, do nothing. Also ensures SS_NOTIFY is on. // HBRUSH CStaticLink::CtlColor(CDC* pDC, UINT nCtlColor) { ASSERT(nCtlColor == CTLCOLOR_STATIC); DWORD dwStyle = GetStyle(); HBRUSH hbr = NULL; if (!m_bNoLink && ((dwStyle & 0xFF) <= SS_RIGHT)) { // this is a text control: set up font and colors if (!(HFONT)m_font) { // first time init: create font LOGFONT lf; GetFont()->GetObject(sizeof(lf), &lf); lf.lfUnderline = TRUE; m_font.CreateFontIndirect(&lf); } // use underline font and visited/unvisited colors pDC->SelectObject(&m_font); pDC->SetTextColor(m_color); pDC->SetBkMode(TRANSPARENT); // return hollow brush to preserve parent background color hbr = (HBRUSH)::GetStockObject(HOLLOW_BRUSH); } return hbr; } ///////////////// // Handle mouse click: navigate link // void CStaticLink::OnLButtonDown(UINT nFlags, CPoint point) { if (!m_bNoLink && !TryNavigate()) { // try window text GetWindowText(m_link); if (!TryNavigate()) { // try resource string m_link.LoadString(GetDlgCtrlID()); if (!TryNavigate()) { // unable to navigate link! MessageBeep(0); TRACE(_T("*** CStaticLink: can't navigate %s!\n"), (LPCTSTR)m_link); m_bNoLink = TRUE; } } } } ////////////////// // Try to navigate the link // BOOL CStaticLink::TryNavigate() { HINSTANCE h = m_link.Navigate(); if ((UINT)h > 32) { // success! m_color = g_colorVisited; // change color Invalidate(); // repaint return TRUE; } return FALSE; } ////////////////// // Set "hand" cursor to cue user that this is a link. If app has not set // g_hCursorLink, then try to get the cursor from winhlp32.exe, // resource 106, which is a pointing finger. This is a bit of a kludge, // but it works. // BOOL CStaticLink::OnSetCursor(CWnd* pWnd, UINT nHitTest, UINT message) { if (!m_bNoLink) { if (g_hCursorLink == NULL) { static bTriedOnce = FALSE; if (!bTriedOnce) { HMODULE hModule = LoadLibrary(_T("winhlp32.exe")); if (hModule) { g_hCursorLink = CopyCursor(::LoadCursor(hModule, MAKEINTRESOURCE(106))); } FreeLibrary(hModule); bTriedOnce = TRUE; } } if (g_hCursorLink) { ::SetCursor(g_hCursorLink); return TRUE; } } return FALSE; } ////////////////// // Normally, a control class is not destoyed when the window is; // however, CPixieDlg creates static controls with "new" instead of // as class members, so it's convenient to allow the option of destroying // object with window. In applications where you want the object to be // destoyed along with the window, you can call constructor with // bDeleteOnDestroy=TRUE. // void CStaticLink::PostNcDestroy() { if (m_bDeleteOnDestroy) delete this; }