求索阁

/* 方法1 */

    QFile theFile(fileNamePath);

    theFile.open(QIODevice::ReadOnly);

    QByteArray ba = QCryptographicHash::hash(theFile.readAll(), QCryptographicHash::Md5);

    theFile.close();

    qDebug() << ba.toHex().constData();

/* 方法2 */
/*
*   获取文件md5值
*/
QByteArray MainWindow::getFileMd5(QString filePath)
{
    QFile localFile(filePath);

    if (!localFile.open(QFile::ReadOnly))
    {
        qDebug() << "file open error.";
        return 0;
    }

    QCryptographicHash ch(QCryptographicHash::Md5);

    quint64 totalBytes = 0;
    quint64 bytesWritten = 0;
    quint64 bytesToWrite = 0;
    quint64 loadSize = 1024 * 4;
    QByteArray buf;

    totalBytes = localFile.size();
    bytesToWrite = totalBytes;

    while (1)
    {
        if(bytesToWrite > 0)
        {
            buf = localFile.read(qMin(bytesToWrite, loadSize));
            ch.addData(buf);
            bytesWritten += buf.length();
            bytesToWrite -= buf.length();
            buf.resize(0);
        }
        else
        {
            break;
        }

        if(bytesWritten == totalBytes)
        {
            break;
        }
    }

    localFile.close();
    QByteArray md5 = ch.result();

    return md5;
}