QT开启外部程序后，当退出时，怎么关闭

QString KillStr = "taskkill /f /im main.exe"

QProcess *Process = new QProcess(this)

Process->start(KillStr)

QString filepath = QDir::currentPath()

    QString fullpath = filepath+"\\pp\\dist\\start"

    QString title = fullpath+"\\main.exe"

    title = title.replace("/","\\")

    fullpath = fullpath.replace("/","\\")

    QProcess p(this)

    p.setWorkingDirectory(fullpath)

    p.start("cmd", QStringList()<<"/c"<<"start main.exe")

    p.waitForStarted()

    p.waitForFinished()

关闭

    QProcess p(this)

    p.setWorkingDirectory(fullpath)

    p.start("cmd", QStringList()<<"/c"<<"taskkill /f /t /im main.exe")

    p.waitForStarted()

    p.waitForFinished()