excep3.cpp

c++的一些源代码

#include    <windows.h>
#include    <stdio.h>
#include    <iostream.h>
//
//  excep3.cpp. Test program for exception handling.
//  compile this program with the following command line
//
//            cl -GX excep3.cpp user32.lib comdlg32.lib
//
//  The -GX enables exception handling. The user32.lib
//  provides the MessageBox function. comdlg32 is used
//  for the open/save file common dialog box.
//
FILE *TestFileFunc (char *szFile);

class COpenFile
{
    public:
        COpenFile();
        ~COpenFile();

        OPENFILENAME m_ofn;

        int m_errno;
        int GetFileName (char *szName, int nSize);
};


main ()
{
    char fn[_MAX_PATH] = {"DooWop.Diddly"};
    FILE *fp;
    while (1)
    {
        try
        {
            fp = TestFileFunc (fn);
            break;
        }
        catch (COpenFile *of)
        {
           int nResult = of->GetFileName (fn, _MAX_PATH);
           delete of;
           if (nResult == IDCANCEL)
               return (-1);
        }
    }
    fclose (fp);
    cout << "Open file " << fn << endl;
}

FILE *TestFileFunc(char *szFile)
{
    FILE *fp = fopen (szFile, "rb");
    if (fp == NULL)
    {
        int err = errno;
        COpenFile *of = new COpenFile;
        of->m_errno = err;
        throw (of);
    }
    return (fp);
}

COpenFile::COpenFile()
{
    memset (&m_ofn, '\0', sizeof (OPENFILENAME));
    m_ofn.lStructSize = sizeof (OPENFILENAME);
}

COpenFile::~COpenFile()
{

}

int COpenFile::GetFileName (char *szName, int nSize)
{
    m_ofn.lpstrFile = szName;
    m_ofn.nMaxFile = nSize;
    m_ofn.lpstrTitle = "Open a File";
    m_ofn.lpstrFilter = "All files (*.*)\0*.*\0";
    BOOL bResult = GetOpenFileName (&m_ofn);
    return (bResult ? IDOK : IDCANCEL);
}