vc++最令人头疼的莫过于异常处理，与内存泄漏。今天愿愿先提出一个异常处理的方案。以供后来者，学习参考之用。
以下是代码，如果不详细，请谅解，我只能保证，我所贴出的代码是经过验证的，是正确的，至于能不能被大家理解，请谅解。
标红色的，是需要注意的。
_cMyExceptionImpl.h 文件内容如下：
#pragma once
#include "_cSetLogFile2.h"
#include "MessageDialog.h"
//#include <boost/exception/info.hpp>
#include <boost/exception/exception.hpp>
#include <boost/throw_exception.hpp>
class _cMyExceptionImpl: //Base for all exception objects we throw.
public virtual std::exception,
public virtual boost::exception
{
public:
static void SetLogFile(const TCHAR * m_szLogFileName) throw();
_cMyExceptionImpl(CString & error_info,CWnd* parentWnd) throw();
_cMyExceptionImpl(const TCHAR * error_tchar,CWnd* parentWnd) throw();
_cMyExceptionImpl(const _cMyExceptionImpl& myExp,CWnd* parentWnd) throw(); // 拷贝构造函数
char const *what() const throw();
virtual ~_cMyExceptionImpl();
private:
CWnd* m_parentWnd;
char const * PrintErrorInfo()const throw();
static _cSetLogFile2 m_setLogFileVar;
};
std::shared_ptr<TCHAR> char_To_TCHAR(const char *chr);
std::shared_ptr<char> __cdecl TCHAR_To_Char(const TCHAR * errorBuffer);
_cMyExceptionImpl.h完
_cMyExceptionImpl.cpp 内容如下：
#include "StdAfx.h"
#include "_cMyExceptionImpl.h"
//#include "boost\scoped_array.hpp"
//#include <boost/exception/all.hpp>
#include <boost/exception/info.hpp>
#include <boost/exception/get_error_info.hpp>
#include "boost/date_time/posix_time/posix_time.hpp"
typedef boost::error_info<struct tag_error_Date,boost::posix_time::ptime> errinfo_time;
typedef boost::error_info<struct tag_error_strSharedChars,std::shared_ptr<char>> errinfo_charStr;
//using namespace boost;
#include <sstream>
std::shared_ptr<TCHAR> char_To_TCHAR(const char *chr)
{
int i=strlen(chr);
DWORD dwLen = MultiByteToWideChar( CP_ACP, 0, chr, -1,NULL, 0);
if(dwLen==0)
{
return NULL;
}
std::shared_ptr<TCHAR> ptr(new TCHAR[dwLen], std::default_delete<TCHAR[]>());
//std::shared_ptr<TCHAR[]> ptr(new TCHAR[dwLen]);
#ifdef UNICODE
if(MultiByteToWideChar( CP_ACP, 0, chr, -1,ptr.get(), dwLen)==0)
{
return NULL;
}
#else
strcpy_s((char *)ptr.get(),dwLen,chr);
#endif
return ptr;
}
std::shared_ptr<char> __cdecl TCHAR_To_Char(const TCHAR * errorBuffer)
{
DWORD dwLen = WideCharToMultiByte(CP_ACP, NULL, errorBuffer, -1, NULL, NULL, NULL, FALSE );
if(dwLen==0)
{
return NULL;
}
//std::shared_ptr<char[]> ptr(new char[dwLen]);
std::shared_ptr<char> ptr(new char[dwLen], std::default_delete<char[]>());
#ifdef UNICODE
if(WideCharToMultiByte(CP_ACP, NULL,
errorBuffer, -1, ptr.get(), dwLen, NULL, FALSE )==0)
{//WideCharToMultiByte(CP_OEMCP,NULL,lpcwszStr,-1,lpszStr,dwSize,NULL,FALSE);
return NULL;
}
#else
strcpy_s(ptr.get(),dwLen,(const char *)errorBuffer);
#endif
return ptr;
}
_cSetLogFile2 _cMyExceptionImpl::m_setLogFileVar;
//static int countkd=0;
//static int countkd2=0;
char const *_cMyExceptionImpl::what()const
{
return PrintErrorInfo();
};
_cMyExceptionImpl::_cMyExceptionImpl(const _cMyExceptionImpl& myExp,CWnd* parentWnd)
:boost::exception(((boost::exception &)myExp))
,std::exception((std::exception &)myExp),m_parentWnd(parentWnd)
{
}
_cMyExceptionImpl::_cMyExceptionImpl(CString & error_info,CWnd* parentWnd)
:m_parentWnd(parentWnd)
{
//TRACE(_T("construct:%d\n"),countkd++);
*this<<errinfo_charStr(TCHAR_To_Char(error_info.GetBuffer()));
error_info.ReleaseBuffer();
}
_cMyExceptionImpl::_cMyExceptionImpl(const TCHAR * error_tchar,CWnd* parentWnd)
:m_parentWnd(parentWnd)
{
*this<<errinfo_charStr(TCHAR_To_Char(error_tchar));
}
_cMyExceptionImpl::~_cMyExceptionImpl()
{
//TRACE(_T("destruct:%d\n"),countkd2++);
}
void _cMyExceptionImpl::SetLogFile(const TCHAR * m_szLogFileName)
{
_cSetLogFile2::SetLogFileName((TCHAR *)m_szLogFileName);
}
char const * _cMyExceptionImpl::PrintErrorInfo()const
{
boost::posix_time::ptime now = boost::posix_time::second_clock::local_time();
char const * const * function=boost::get_error_info<boost::throw_function>(*this);
char const * const * file=boost::get_error_info<boost::throw_file>(*this);
int const * line=boost::get_error_info<boost::throw_line>(*this);
const std::shared_ptr<char> * data=boost::get_error_info<errinfo_charStr>(*this);
std::ostringstream ostr;//下面的代码看见吗？该异常处理机制，可以输出自定义提示，出错函数，以及出错源代码行！！
ostr<<"错误提示:"<<data->get()<<"\r\n"
<<"日期:"<<now<<"\r\n"
<<"文件:"<<*file<<"\r\n"
<<"函数:"<<*function<<"\r\n"
<<"行数:"<<*line<<"\r\n"<<std::endl;
std::string tmpString=ostr.str();//=*data;//ostr.str();
const char *p=tmpString.c_str();
std::shared_ptr<TCHAR> ptrStr(char_To_TCHAR(p));
if(m_parentWnd!=NULL)
{
ShowMessageDialog(ptrStr.get(),_T("错误"),m_parentWnd);
}
else{
::AfxMessageBox(ptrStr.get());
}
_cSetLogFile2::PrintErrorInfo(ptrStr.get());
return data->get();
}
_cMyExceptionImpl.cpp 完
_cSetLogFile2.h 如下：
#pragma once
#include <fstream>
#include <memory>
#include <functional>
typedef std::basic_ofstream<TCHAR> _MyOfstream;
//auto Delete = [](_MyOfstream *p) {if(p->is_open())p->close();delete p;};
class _cOfstreamDeleter{
// What should be the default?? No deleter? delete? I choose to
// mimic the default of unique_ptr.
public:
_cOfstreamDeleter(): f([](_MyOfstream *p) {
if(p->is_open()){
p->close();
}
delete p;})
{};
// allow the user to specify what type of deleter to use
explicit _cOfstreamDeleter(std::tr1::function< void(_MyOfstream *)> const &f_ )
: f(f_)
{};
void operator()(_MyOfstream *p) const
{
f(p);
};
private:
std::tr1::function< void(_MyOfstream *)> f;
};
typedef std::unique_ptr<_MyOfstream,_cOfstreamDeleter> _MyOfstreamUnp;
class _cSetLogFile2{
//class _cMyExceptionImpl;
private:
static _MyOfstreamUnp m_unp_Fout;
static _MyOfstreamUnp InitFout(void);
//static std::ofstream fout;
public:
_cSetLogFile2(void);
virtual ~_cSetLogFile2();
public:
// //return fout;
//};
static void SetLogFileName( PTSTR pszLogFileName );
static void PrintErrorInfo(const TCHAR* exp){
(*m_unp_Fout).imbue(std::locale("chs"));
*m_unp_Fout<<std::endl<<exp;};
//static TCHAR m_szLogFileName[MAX_PATH];
//static HANDLE m_hReportFile;
};
_cSetLogFile2.cpp
#include "StdAfx.h"
#include "_cSetLogFile2.h"
#include "_cMyExceptionImpl.h"
//TCHAR _cSetLogFile2::m_szLogFileName[MAX_PATH];
//HANDLE _cSetLogFile2::m_hReportFile;
//std::ofstream _cSetLogFile2::fout;
_MyOfstreamUnp _cSetLogFile2::InitFout(void)
{
static TCHAR szLogFileName[MAX_PATH];
GetModuleFileName( 0, szLogFileName, MAX_PATH );
// Look for the '.' before the "EXE" extension. Replace the extension
// with "RPT"
PTSTR pszDot = _tcsrchr( szLogFileName, _T('.') );
if ( pszDot )
{
pszDot++; // Advance past the '.'
if ( _tcslen(pszDot) >= 3 )
_tcscpy_s(pszDot,_tcslen(_T("RPT"))+1,_T("RPT"));// "RPT" -> "Report"
//_tcscpy( pszDot, _T("RPT") ); // "RPT" -> "Report"
}
_MyOfstreamUnp tmpFout(new _MyOfstream(szLogFileName,std::ios::app),_cOfstreamDeleter());
return tmpFout;
}
_MyOfstreamUnp _cSetLogFile2::m_unp_Fout=InitFout();
_cSetLogFile2::_cSetLogFile2(void)
{
}
_cSetLogFile2::~_cSetLogFile2()
{
//m_unp_Fout->close();
//fout.close();
}
void _cSetLogFile2::SetLogFileName( PTSTR pszLogFileName )
{
m_unp_Fout.reset(new _MyOfstream(pszLogFileName,std::ios::app));
//fout.open(pszLogFileName,std::ios::out|std::ios::app);
}
_cSetLogFile2.cpp完
// MessageDialog.h : MessageDialog DLL 的主头文件
//
#pragma once
#ifndef __AFXWIN_H__
#error "在包含此文件之前包含“stdafx.h”以生成 PCH 文件"
#endif
#include "resource.h" // 主符号
// CMessageDialog 对话框
class CMessageDialog : public CDialogEx
{
DECLARE_DYNAMIC(CMessageDialog)
public:
explicit CMessageDialog(const CString& ErrorInfoStr,
const CString& TitleStr=_T("错误！"),
CWnd* pParent = NULL); // 标准构造函数
virtual ~CMessageDialog();
// 对话框数据
enum { IDD = IDD_DIALOG_ERROR };
protected:
virtual void DoDataExchange(CDataExchange* pDX); // DDX/DDV 支持
private:
CString m_TitleStr;
CString m_ErrorInfoStr;
DECLARE_MESSAGE_MAP()
CEdit m_CEdit_ErrorContent;
virtual BOOL OnInitDialog();
public:
};
void ShowMessageDialog(//不能在易失模态对话框前使用
const TCHAR * const strErrorInfo=_T("错误！"),
const TCHAR * const strTitle=_T("错误！"),CWnd* pParent=NULL);
void ShowMessageDialog(//不能在易失模态对话框前使用
CString strErrorInfo=_T("错误！"),
CString strTitle=_T("错误！"),CWnd* pParent=NULL);
MessageDialog.h完
MessageDialog.cpp 内容如下：
// MessageDialog.cpp : 定义 DLL 的初始化例程。
//
#include "stdafx.h"
#ifdef _DEBUG
#define new DEBUG_NEW
#endif
//
//TODO: 如果此 DLL 相对于 MFC DLL 是动态链接的，
// 则从此 DLL 导出的任何调入
// MFC 的函数必须将 AFX_MANAGE_STATE 宏添加到
// 该函数的最前面。
//
// 例如:
//
// extern "C" BOOL PASCAL EXPORT ExportedFunction()
// {
// AFX_MANAGE_STATE(AfxGetStaticModuleState());
// // 此处为普通函数体
// }
//
// 此宏先于任何 MFC 调用
// 出现在每个函数中十分重要。这意味着
// 它必须作为函数中的第一个语句
// 出现，甚至先于所有对象变量声明，
// 这是因为它们的构造函数可能生成 MFC
// DLL 调用。
//
// 有关其他详细信息，
// 请参阅 MFC 技术说明 33 和 58。
//
// CMessageDialogApp
//
//BEGIN_MESSAGE_MAP(CMessageDialogApp, CWinApp)
//END_MESSAGE_MAP()
//
//
//// CMessageDialogApp 构造
//
//CMessageDialogApp::CMessageDialogApp()
//{
// // TODO: 在此处添加构造代码，
// // 将所有重要的初始化放置在 InitInstance 中
//}
//
//
//// 唯一的一个 CMessageDialogApp 对象
//
//CMessageDialogApp theApp;
//
//
//// CMessageDialogApp 初始化
//
//BOOL CMessageDialogApp::InitInstance()
//{
// CWinApp::InitInstance();
//
// return TRUE;
//}
// MessageDialog.cpp : 实现文件
//
#include "MessageDialog.h"
#include "_cMyExceptionImpl.h"
// CMessageDialog 对话框
IMPLEMENT_DYNAMIC(CMessageDialog, CDialogEx)
CMessageDialog::CMessageDialog(const CString& ErrorInfoStr,
const CString& TitleStr,CWnd* pParent /*=NULL*/)
: CDialogEx(CMessageDialog::IDD, pParent),m_TitleStr(TitleStr)
,m_ErrorInfoStr(ErrorInfoStr)
{
}
CMessageDialog::~CMessageDialog()
{
}
void CMessageDialog::DoDataExchange(CDataExchange* pDX)
{
CDialogEx::DoDataExchange(pDX);
DDX_Control(pDX, IDC_EDIT1, m_CEdit_ErrorContent);
}
BEGIN_MESSAGE_MAP(CMessageDialog, CDialogEx)
END_MESSAGE_MAP()
// CMessageDialog 消息处理程序
BOOL CMessageDialog::OnInitDialog()
{
CDialogEx::OnInitDialog();
// TODO: 在此添加额外的初始化
this->SetWindowTextW(m_TitleStr);
m_CEdit_ErrorContent.SetWindowTextW(m_ErrorInfoStr);
return TRUE; // return TRUE unless you set the focus to a control
// 异常: OCX 属性页应返回 FALSE
}
void ShowMessageDialog(
const TCHAR * const strErrorInfo,
const TCHAR * const strTitle,CWnd* pParent)
{
//AFX_MANAGE_STATE(AfxGetStaticModuleState());
try{
CMessageDialog dlg(strErrorInfo,strTitle,pParent);
dlg.DoModal();
}catch(...)
{
::AfxMessageBox(_T("My消息对话框显示错误！"));
}
}
void ShowMessageDialog(
CString strErrorInfo,
CString strTitle,CWnd* pParent)
{
//AFX_MANAGE_STATE(AfxGetStaticModuleState());
const TCHAR * tmpTCHAR=strErrorInfo.GetBuffer(0);
const TCHAR * tmpTCHAR2=strTitle.GetBuffer(0);
ShowMessageDialog(tmpTCHAR,tmpTCHAR2,pParent);
strErrorInfo.ReleaseBuffer();
strTitle.ReleaseBuffer();
}
MessageDialog.cpp 完
以下是应用代码：注意红字
BOOL CFormViewFormatTrans_JinSan::readSettings(void)
{
try{
CDocumentSetting*pTmpDoc=(CDocumentSetting*)theApp.GetCDocumentSetting();
if(pTmpDoc==NULL||pTmpDoc->m_DBObjs==NULL||
pTmpDoc->m_DBObjs->m_pDb==NULL||
pTmpDoc->m_DBObjs->m_pDb->m_pConnection==NULL||
pTmpDoc->m_DBObjs->m_pDb->m_pConnection->GetState() == adStateClosed)
{
CString m_MDBFilePath,SqlStr,strTmp;
m_MDBFilePath=GetAppPath();
m_MDBFilePath+=_T("\\TmpDB_Setting_JinSan.mdb");
BOOL bIsExist=PathFileExists(m_MDBFilePath);
if(bIsExist==FALSE)
{
BOOST_THROW_EXCEPTION(_cMyExceptionImpl(_T("设置数据库文件不存在!"),this));
}
CString StrSql;
StrSql.Format(_T("Provider=Microsoft.Jet.OLEDB.4.0;Data Source=%s;\
User ID=admin;Password=;Jet OLEDB:Database Password=1234567;"),
m_MDBFilePath);
//m_pConnection->PutMode(adModeReadWrite);
//_ConnectionPtr m_pConnection;
//m_pConnection.CreateInstance(__uuidof(Connection));
_cDataBaseCommonVarSetting m_DBObjs(StrSql);
if(ReadProduceSettings(m_DBObjs)==FALSE)
{
BOOST_THROW_EXCEPTION(_cMyExceptionImpl(_T("ReadProduceSettings失败!"),this));
}
if(CreateComlumnMingChenMap(m_DBObjs)==FALSE)
{
BOOST_THROW_EXCEPTION(_cMyExceptionImpl(_T("CreateComlumnMingChenMap失败!"),this));
}
}
else
{
_cDataBaseCommonVarSetting m_DBObjs(((CDocumentSetting*)theApp.GetCDocumentSetting())->m_DBObjs->m_pDb->GetActiveConnection());
if(ReadProduceSettings(m_DBObjs)==FALSE)
{
BOOST_THROW_EXCEPTION(_cMyExceptionImpl(_T("ReadProduceSettings失败!"),this));
}
if(CreateComlumnMingChenMap(m_DBObjs)==FALSE)
{
BOOST_THROW_EXCEPTION(_cMyExceptionImpl(_T("CreateComlumnMingChenMap失败!"),this));
}
}
}catch(std::exception & exp )
{
exp.what();
return FALSE;
}
catch(_com_error &e)
{
dump_com_error(e);
return FALSE;
}
catch(...)
{
return FALSE;
}
return TRUE;
}
看到了吗，VC++的异常处理也可以做到像java那样，用一个语句就搞定，在异常处理模块中，也不用很多判断，尽情享用简洁代码的快感吧。