void CWAVinfoDlg::OnBnClickedLoad() //读取信息,存入Buf中
{
    DWORD dwFileLen;
    pBuf = NULL;

    CFileDialog fileDlg(TRUE);
    fileDlg.m_ofn.lpstrTitle=_T("打开文件");
    fileDlg.m_ofn.lpstrFilter=_T("Wav音频文件(*.wav)\0*.wav\0");
    if(IDOK == fileDlg.DoModal())
    {
        m_nPath = fileDlg.GetPathName();
        FileName = fileDlg.GetFileName();
    }
    CFile file(m_nPath,CFile::modeRead|CFile::typeBinary|CFile::shareDenyWrite);
    dwFileLen = file.GetLength();
    FileSize = dwFileLen;
    
    //pBuf = new BYTE[dwFileLen + 1];
    pBuf = new unsigned char[dwFileLen + 1];        //定义pBuf缓冲区,长度为 存档文件的长度 +1
    pBuf[dwFileLen] = 0;                            //设置pBuf的索引(最后一个元素)为0,表示结束
    file.Read(pBuf,dwFileLen);                        //将长度为dwFileLen的字符串从file中写到pBuf中,也就是全部,//**可以将二进制文件全部读入
    file.Close();
    UpdateData(FALSE);

    analyse();
}

void CWAVinfoDlg::analyse()//分析wav文件信息
{
    bool riff = false; //首先判断wav文件标志
 bool wave = false;
    bool fmt = false;

    if ((pBuf[0] == 'R') && (pBuf[1] == 'I') && (pBuf[2] == 'F') && (pBuf[3] == 'F'))
    {
        riff = true;
    }
    if ((pBuf[8] == 'W') && (pBuf[9] == 'A') && (pBuf[10] == 'V') && (pBuf[11] == 'E'))
    {
        wave = true;
    }
    if ((pBuf[12] == 'f') && (pBuf[13] == 'm') && (pBuf[14] == 't'))
    {
        fmt = true;
    }

    if (riff && wave && fmt) //wav文件标志正确
    {
        CString wav_size_str;
        CString FileSize_str;
        unsigned double wav_size = 0.0;
        int channel_num = 0;
        int sample_rate = 0;
        int sample_bit = 0;
        unsigned double length = 0.0;
        CString length_str;

        wav_size = pBuf[43]*256*256*256 + pBuf[42]*256*256 + pBuf[41]*256 + pBuf[40];
        channel_num = pBuf[23]*256 + pBuf[22];
        sample_rate = pBuf[27]*256*256*256 + pBuf[26]*256*256 + pBuf[25]*256 + pBuf[24];
        sample_bit = pBuf[35]*256 + pBuf[34];

        if (wav_size >= (1024*1024)) //通过文件信息得到wav大小
        {
            wav_size_str.Format(L"%.2f MB",(wav_size/(1024.0*1024.0)));
        }
        else if (wav_size >= 1024)
        {
            wav_size_str.Format(L"%.2f KB",(wav_size/1024.0));
        }
        else
        {
            wav_size_str.Format(L"%f B",wav_size);
        }
        //通过wav大小得到持续时间(单位:秒)
        length = (wav_size*8.0)/(sample_rate*channel_num*sample_bit*1.0);

        if (FileSize >= (1024*1024)) //文件实际大小
        {
            FileSize_str.Format(L"%.2f MB",(FileSize/(1024.0*1024.0)));
        }
        else if (FileSize >= 1024)
        {
            FileSize_str.Format(L"%.2f KB",(FileSize/1024.0));
        }
        else
        {
            FileSize_str.Format(L"%f B",FileSize);
        }

        CTimeSpan ts(length); //格式化时间显示
        length_str = ts.Format(_T("%H:%M:%S"));

        MessageBox(L"wav文件载入成功");
        m_nInfo.Format(L"文件大小:  %s\r\nWav大小:  %s\r\n通道数目:  %d\r\n采样率   :  %d HZ\r\n采样位数:  %d bits\r\n持续时间:  %s\r\n",FileSize_str,wav_size_str,channel_num,sample_rate,sample_bit,length_str);
        UpdateData(FALSE);
    }
    else
    {
        MessageBox(L"wav文件验证错误,不是正确的wav文件");
    }
}