MFC 中创建简单超链接
MFC SDI程序在菜单的最后通常会有一个帮助的菜单项，点击后弹出一个关于程序基本信息的对话框（CAboutDlg），想在这个界面添加一条超链接，指向指定的网页，这个网页上存放介绍这个程序更多的信息。查资料说API函数使用ShellExecute可以实现，试了一下，没有成功，这种方法后续再补充。先介绍一下另外一种实现方法（注：这种方法也也是在网上搜集整理的）。
步骤如下：
1) 新建一个MFC单文档应用程序，命名为test。
2) 打开解决方案视图，在头文件中按照步骤：右键---添加---新建项---头文件（.h），命名为HyperLink.h ，在这个头文件中添加下面的代码：
//***************************************************************************
// Description : Hyper Link Static Class
// File Name : HyperLink.H
// Created :
// Email :
//***************************************************************************
#if !defined(AFX_HYPERLINK_H__D1625061_574B_11D1_ABBA_00A0243D1382__INCLUDED_)
#define AFX_HYPERLINK_H__D1625061_574B_11D1_ABBA_00A0243D1382__INCLUDED_
#if _MSC_VER >= 1000
#pragma once
#endif // _MSC_VER >= 1000
/////////////////////////////////////////////////////////////////////////////
// CHyperLink window
class CHyperLink : public CStatic
{
// Construction/destruction
public:
CHyperLink();
virtual ~CHyperLink();
public:
enum UnderLineOptions { ulHover = -1, ulNone = 0, ulAlways = 1};
// Attributes
public:
void SetURL(CString strURL);
CString GetURL() const;
void SetColours(COLORREF crLinkColour, COLORREF crVisitedColour,
COLORREF crHoverColour = -1);
COLORREF GetLinkColour() const;
COLORREF GetVisitedColour() const;
COLORREF GetHoverColour() const;
void SetVisited(BOOL bVisited = TRUE);
BOOL GetVisited() const;
void SetLinkCursor(HCURSOR hCursor);
HCURSOR GetLinkCursor() const;
void SetUnderline(int nUnderline = ulHover);
int GetUnderline() const;
void SetAutoSize(BOOL bAutoSize = TRUE);
BOOL GetAutoSize() const;
// Overrides
// ClassWizard generated virtual function overrides
//{{AFX_VIRTUAL(CHyperLink)
public:
virtual BOOL PreTranslateMessage(MSG* pMsg);
virtual BOOL DestroyWindow();
protected:
virtual void PreSubclassWindow();
//}}AFX_VIRTUAL
// Implementation
protected:
HINSTANCE GotoURL(LPCTSTR url, int showcmd);
void ReportError(int nError);
LONG GetRegKey(HKEY key, LPCTSTR subkey, LPTSTR retdata);
void PositionWindow();
void SetDefaultCursor();
// Protected attributes
protected:
COLORREF m_crLinkColour, m_crVisitedColour; // Hyperlink colours
COLORREF m_crHoverColour; // Hover colour
BOOL m_bOverControl; // cursor over control?
BOOL m_bVisited; // Has it been visited?
int m_nUnderline; // underline hyperlink?
BOOL m_bAdjustToFit; // Adjust window size to fit text?
CString m_strURL; // hyperlink URL
CFont m_UnderlineFont; // Font for underline display
CFont m_StdFont; // Standard font
HCURSOR m_hLinkCursor; // Cursor for hyperlink
CToolTipCtrl m_ToolTip; // The tooltip
UINT m_nTimerID;
// Generated message map functions
protected:
//{{AFX_MSG(CHyperLink)
afx_msg HBRUSH CtlColor(CDC* pDC, UINT nCtlColor);
afx_msg BOOL OnSetCursor(CWnd* pWnd, UINT nHitTest, UINT message);
afx_msg void OnMouseMove(UINT nFlags, CPoint point);
afx_msg void OnTimer(UINT nIDEvent);
afx_msg BOOL OnEraseBkgnd(CDC* pDC);
//}}AFX_MSG
afx_msg void OnClicked();
DECLARE_MESSAGE_MAP()
};
/////////////////////////////////////////////////////////////////////////////
//{{AFX_INSERT_LOCATION}}
// Microsoft Developer Studio will insert additional declarations immediately before the previous line.
#endif // !defined(AFX_HYPERLINK_H__D1625061_574B_11D1_ABBA_00A0243D1382__INCLUDED_)
3) 再添加对应的源文件。步骤：在解决方案视图中，右键点击源文件---添加---新建项---C++文件（.cpp），命名为 HyperLink.cpp ，在这个头文件中添加下面的代码：
// HyperLink.cpp : implementation file
// HyperLink static control. Will open the default browser with the given URL
// when the user clicks on the link.
#include "stdafx.h"
#include "HyperLink.h"
#include "atlconv.h" // for Unicode conversion - requires #include <afxdisp.h> // MFC OLE automation classes
#ifdef _DEBUG
#define new DEBUG_NEW
#undef THIS_FILE
static char THIS_FILE[] = __FILE__;
#endif
#define TOOLTIP_ID 1
/////////////////////////////////////////////////////////////////////////////
// CHyperLink
CHyperLink::CHyperLink()
{
m_hLinkCursor = NULL; // No cursor as yet
m_crLinkColour = RGB( 0, 0, 238); // Blue
m_crVisitedColour = RGB( 85, 26, 139); // Purple
m_crHoverColour = RGB(255, 0, 0); // Red
m_bOverControl = FALSE; // Cursor not yet over control
m_bVisited = FALSE; // Hasn't been visited yet.
m_nUnderline = ulHover; // Underline the link?
m_bAdjustToFit = TRUE; // Resize the window to fit the text?
m_nTimerID = 100;
m_strURL.Empty();
}
CHyperLink::~CHyperLink()
{
m_UnderlineFont.DeleteObject();
}
/////////////////////////////////////////////////////////////////////////////
// CHyperLink overrides
BOOL CHyperLink::DestroyWindow()
{
KillTimer(m_nTimerID);
return CStatic::DestroyWindow();
}
BOOL CHyperLink::PreTranslateMessage(MSG* pMsg)
{
m_ToolTip.RelayEvent(pMsg);
return CStatic::PreTranslateMessage(pMsg);
}
void CHyperLink::PreSubclassWindow()
{
// We want to get mouse clicks via STN_CLICKED
DWORD dwStyle = GetStyle();
::SetWindowLong(GetSafeHwnd(), GWL_STYLE, dwStyle | SS_NOTIFY);
// Set the URL as the window text
if (m_strURL.IsEmpty())
GetWindowText(m_strURL);
// Check that the window text isn't empty. If it is, set it as the URL.
CString strWndText;
GetWindowText(strWndText);
if (strWndText.IsEmpty())
{
ASSERT(!m_strURL.IsEmpty()); // Window and URL both NULL. DUH!
SetWindowText(m_strURL);
}
CFont* pFont = GetFont();
if (!pFont)
{
HFONT hFont = (HFONT)GetStockObject(DEFAULT_GUI_FONT);
if (hFont == NULL)
hFont = (HFONT) GetStockObject(ANSI_VAR_FONT);
if (hFont)
pFont = CFont::FromHandle(hFont);
}
ASSERT(pFont->GetSafeHandle());
// Create the underline font
LOGFONT lf;
pFont->GetLogFont(&lf);
m_StdFont.CreateFontIndirect(&lf);
lf.lfUnderline = (BYTE) TRUE;
m_UnderlineFont.CreateFontIndirect(&lf);
PositionWindow(); // Adjust size of window to fit URL if necessary
SetDefaultCursor(); // Try and load up a "hand" cursor
SetUnderline();
// Create the tooltip
CRect rect;
GetClientRect(rect);
m_ToolTip.Create(this);
m_ToolTip.AddTool(this, m_strURL, rect, TOOLTIP_ID);
CStatic::PreSubclassWindow();
}
BEGIN_MESSAGE_MAP(CHyperLink, CStatic)
//{{AFX_MSG_MAP(CHyperLink)
ON_WM_CTLCOLOR_REFLECT()
ON_WM_SETCURSOR()
ON_WM_MOUSEMOVE()
ON_WM_TIMER()
ON_CONTROL_REFLECT(STN_CLICKED, OnClicked)
ON_WM_ERASEBKGND()
//}}AFX_MSG_MAP
END_MESSAGE_MAP()
/////////////////////////////////////////////////////////////////////////////
// CHyperLink message handlers
void CHyperLink::OnClicked()
{
m_bOverControl = FALSE;
int result = (int)GotoURL(m_strURL, SW_SHOW);
m_bVisited = (result > HINSTANCE_ERROR);
if (!m_bVisited)
{
MessageBeep(MB_ICONEXCLAMATION); // Unable to follow link
ReportError(result);
}
else
SetVisited(); // Repaint to show visited colour
}
HBRUSH CHyperLink::CtlColor(CDC* pDC, UINT nCtlColor)
{
ASSERT(nCtlColor == CTLCOLOR_STATIC);
if (m_bOverControl)
pDC->SetTextColor(m_crHoverColour);
else if (m_bVisited)
pDC->SetTextColor(m_crVisitedColour);
else
pDC->SetTextColor(m_crLinkColour);
// transparent text.
pDC->SetBkMode(TRANSPARENT);
return (HBRUSH)GetStockObject(NULL_BRUSH);
}
void CHyperLink::OnMouseMove(UINT nFlags, CPoint point)
{
if (!m_bOverControl) // Cursor has just moved over control
{
m_bOverControl = TRUE;
if (m_nUnderline == ulHover)
SetFont(&m_UnderlineFont);
Invalidate();
SetTimer(m_nTimerID, 100, NULL);
}
CStatic::OnMouseMove(nFlags, point);
}
void CHyperLink::OnTimer(UINT nIDEvent)
{
CPoint p(GetMessagePos());
ScreenToClient(&p);
CRect rect;
GetClientRect(rect);
if (!rect.PtInRect(p))
{
m_bOverControl = FALSE;
KillTimer(m_nTimerID);
if (m_nUnderline != ulAlways)
SetFont(&m_StdFont);
rect.bottom+=10;
InvalidateRect(rect);
}
CStatic::OnTimer(nIDEvent);
}
BOOL CHyperLink::OnSetCursor(CWnd* /*pWnd*/, UINT /*nHitTest*/, UINT /*message*/)
{
if (m_hLinkCursor)
{
::SetCursor(m_hLinkCursor);
return TRUE;
}
return FALSE;
}
BOOL CHyperLink::OnEraseBkgnd(CDC* pDC)
{
CRect rect;
GetClientRect(rect);
pDC->FillSolidRect(rect, ::GetSysColor(COLOR_3DFACE));
return TRUE;
}
/////////////////////////////////////////////////////////////////////////////
// CHyperLink operations
void CHyperLink::SetURL(CString strURL)
{
m_strURL = strURL;
if (::IsWindow(GetSafeHwnd()))
{
PositionWindow();
m_ToolTip.UpdateTipText(strURL, this, TOOLTIP_ID);
}
}
CString CHyperLink::GetURL() const
{
return m_strURL;
}
void CHyperLink::SetColours(COLORREF crLinkColour, COLORREF crVisitedColour,
COLORREF crHoverColour /* = -1 */)
{
m_crLinkColour = crLinkColour;
m_crVisitedColour = crVisitedColour;
if (crHoverColour == -1)
m_crHoverColour = ::GetSysColor(COLOR_HIGHLIGHT);
else
m_crHoverColour = crHoverColour;
if (::IsWindow(m_hWnd))
Invalidate();
}
COLORREF CHyperLink::GetLinkColour() const
{
return m_crLinkColour;
}
COLORREF CHyperLink::GetVisitedColour() const
{
return m_crVisitedColour;
}
COLORREF CHyperLink::GetHoverColour() const
{
return m_crHoverColour;
}
void CHyperLink::SetVisited(BOOL bVisited /* = TRUE */)
{
m_bVisited = bVisited;
if (::IsWindow(GetSafeHwnd()))
Invalidate();
}
BOOL CHyperLink::GetVisited() const
{
return m_bVisited;
}
void CHyperLink::SetLinkCursor(HCURSOR hCursor)
{
m_hLinkCursor = hCursor;
if (m_hLinkCursor == NULL)
SetDefaultCursor();
}
HCURSOR CHyperLink::GetLinkCursor() const
{
return m_hLinkCursor;
}
void CHyperLink::SetUnderline(int nUnderline /*=ulHover*/)
{
if (m_nUnderline == nUnderline)
return;
if (::IsWindow(GetSafeHwnd()))
{
if (nUnderline == ulAlways)
SetFont(&m_UnderlineFont);
else
SetFont(&m_StdFont);
Invalidate();
}
m_nUnderline = nUnderline;
}
int CHyperLink::GetUnderline() const
{
return m_nUnderline;
}
void CHyperLink::SetAutoSize(BOOL bAutoSize /* = TRUE */)
{
m_bAdjustToFit = bAutoSize;
if (::IsWindow(GetSafeHwnd()))
PositionWindow();
}
BOOL CHyperLink::GetAutoSize() const
{
return m_bAdjustToFit;
}
// Move and resize the window so that the window is the same size
// as the hyperlink text. This stops the hyperlink cursor being active
// when it is not directly over the text. If the text is left justified
// then the window is merely shrunk, but if it is centred or right
// justified then the window will have to be moved as well.
void CHyperLink::PositionWindow()
{
if (!::IsWindow(GetSafeHwnd()) || !m_bAdjustToFit)
return;
// Get the current window position
CRect WndRect, ClientRect;
GetWindowRect(WndRect);
GetClientRect(ClientRect);
ClientToScreen(ClientRect);
CWnd* pParent = GetParent();
if (pParent)
{
pParent->ScreenToClient(WndRect);
pParent->ScreenToClient(ClientRect);
}
// Get the size of the window text
CString strWndText;
GetWindowText(strWndText);
CDC* pDC = GetDC();
CFont* pOldFont = pDC->SelectObject(&m_UnderlineFont);
CSize Extent = pDC->GetTextExtent(strWndText);
pDC->SelectObject(pOldFont);
ReleaseDC(pDC);
// Adjust for window borders
Extent.cx += WndRect.Width() - ClientRect.Width();
Extent.cy += WndRect.Height() - ClientRect.Height();
// Get the text justification via the window style
DWORD dwStyle = GetStyle();
// Recalc the window size and position based on the text justification
if (dwStyle & SS_CENTERIMAGE)
WndRect.DeflateRect(0, (WndRect.Height() - Extent.cy)/2);
else
WndRect.bottom = WndRect.top + Extent.cy;
if (dwStyle & SS_CENTER)
WndRect.DeflateRect((WndRect.Width() - Extent.cx)/2, 0);
else if (dwStyle & SS_RIGHT)
WndRect.left = WndRect.right - Extent.cx;
else // SS_LEFT = 0, so we can't test for it explicitly
WndRect.right = WndRect.left + Extent.cx;
// Move the window
SetWindowPos(NULL, WndRect.left, WndRect.top, WndRect.Width(), WndRect.Height(), SWP_NOZORDER);
}
/////////////////////////////////////////////////////////////////////////////
// CHyperLink implementation
// The following appeared in Paul DiLascia's Jan 1998 MSJ articles.
// It loads a "hand" cursor from the winhlp32.exe module
void CHyperLink::SetDefaultCursor()
{
if (m_hLinkCursor == NULL) // No cursor handle - load our own
{
// Get the windows directory
CString strWndDir;
GetWindowsDirectory(strWndDir.GetBuffer(MAX_PATH), MAX_PATH);
strWndDir.ReleaseBuffer();
strWndDir += _T("");
// This retrieves cursor #106 from winhlp32.exe, which is a hand pointer
HMODULE hModule = LoadLibrary(strWndDir);
if (hModule) {
HCURSOR hHandCursor = ::LoadCursor(hModule, MAKEINTRESOURCE(106));
if (hHandCursor)
m_hLinkCursor = CopyCursor(hHandCursor);
}
FreeLibrary(hModule);
}
}
LONG CHyperLink::GetRegKey(HKEY key, LPCTSTR subkey, LPTSTR retdata)
{
HKEY hkey;
LONG retval = RegOpenKeyEx(key, subkey, 0, KEY_QUERY_VALUE, &hkey);
if (retval == ERROR_SUCCESS) {
long datasize = MAX_PATH;
TCHAR data[MAX_PATH];
RegQueryValue(hkey, NULL, data, &datasize);
lstrcpy(retdata,data);
RegCloseKey(hkey);
}
return retval;
}
void CHyperLink::ReportError(int nError)
{
CString str;
switch (nError)
{
case 0: str = "The operating system is out\nof memory or resources."; break;
case SE_ERR_PNF: str = "The specified path was not found."; break;
case SE_ERR_FNF: str = "The specified file was not found."; break;
case ERROR_BAD_FORMAT: str = "The .EXE file is invalid\n(non-Win32 .EXE or error in .EXE image)."; break;
case SE_ERR_ACCESSDENIED: str = "The operating system denied\naccess to the specified file."; break;
case SE_ERR_ASSOCINCOMPLETE: str = "The filename association is\nincomplete or invalid."; break;
case SE_ERR_DDEBUSY: str = "The DDE transaction could not\nbe completed because other DDE transactions\nwere being processed."; break;
case SE_ERR_DDEFAIL: str = "The DDE transaction failed."; break;
case SE_ERR_DDETIMEOUT: str = "The DDE transaction could not\nbe completed because the request timed out."; break;
case SE_ERR_DLLNOTFOUND: str = "The specified dynamic-link library was not found."; break;
case SE_ERR_NOASSOC: str = "There is no application associated\nwith the given filename extension."; break;
case SE_ERR_OOM: str = "There was not enough memory to complete the operation."; break;
case SE_ERR_SHARE: str = "A sharing violation occurred. ";
default: str.Format(_T("Unknown Error (%d) occurred."), nError); break;
}
str += _T("Unable to open hyperlink:\n\n") /*+ str*/;
AfxMessageBox(str, MB_ICONEXCLAMATION | MB_OK);
}
HINSTANCE CHyperLink::GotoURL(LPCTSTR url, int showcmd)
{
TCHAR key[MAX_PATH + MAX_PATH];
// First try ShellExecute()
HINSTANCE result = ShellExecute(NULL, _T("open"), url, NULL,NULL, showcmd);
// If it failed, get the .htm regkey and lookup the program
if ((UINT)result <= HINSTANCE_ERROR)
{
if (GetRegKey(HKEY_CLASSES_ROOT, _T(".htm"), key) == ERROR_SUCCESS)
{
lstrcat(key, _T(""));
if (GetRegKey(HKEY_CLASSES_ROOT,key,key) == ERROR_SUCCESS)
{
TCHAR *pos;
pos = _tcsstr(key, _T("\"%1\""));
if (pos == NULL) { // No quotes found
pos = _tcsstr(key, _T("%1")); // Check for %1, without quotes
if (pos == NULL) // No parameter at all...
pos = key+lstrlen(key)-1;
else
*pos = '\0'; // Remove the parameter
}
else
{
*pos = '\0'; // Remove the parameter
}
lstrcat(pos, _T(" "));
lstrcat(pos, url);
USES_CONVERSION;
result = (HINSTANCE) WinExec(T2A(key),showcmd);
}
}
}
return result;
}
4) 在资源视图中，打开Dialog目录下的IDD_ABOUTBOX，在恰当的位置放一个静态文本框控件，将他的ID改为 IDC_LINK，属性框中的caption中添加你需要显示的文字。
5) 找到CAboutDlg定义的源文件（test.cpp），先添加 #include "HyperLink.h" ，再在类CAboutDlg中添加超链接控件的声明 public: CHyperLink m_cHyperhttp; 再将这个控件和ID为 IDC_LINK的静态文本框关联。实现方法是在类CAboutDlg的成员函数DoDataExchange(CDataExchange* pDX)中添加代码：DDX_Control(pDX,IDC_LINK,m_cHyperhttp)
6) 最后在这个类的初始化（构造）函数中添加：
CString cStrURL= L"http://www.baidu.com";//网页
CString cStr=L"mailto:[email protected]";//邮箱
m_cHyperhttp.SetURL(/*cStrURL*/cStr);//链接/*百度*/邮箱
m_cHyperhttp.SetUnderline(false);//去掉下划线
注：在默认邮件客户端中打开新邮件窗口，并自动填入收件人地址。若指定多个收件人地址，则收件人地址之间必须用分号或逗号分隔开。运行程序，点击添加静态文本框的区域（有识别）即可链接到设定的网页。
（其他实现方法后续再做总结）