Why does QProcess fail to execute the.bat command to open .exe in QService?

[mirro]

Start_UE.ps1 file

Start-Process -FilePath D:/workplace/UE_2025_QingYunDianTra/trunk/package/InstallUEPlatform/package/WindowsNoEditor/DTSDK/Binaries/Win64/DTSDK-Win64-Shipping.exe

StartServer.bat file

@echo off
setlocal
net session >nul 2>&1
if %errorlevel% neq 0 (
    powershell -Command "Start-Process -FilePath '%~f0' -Verb RunAs"
    exit /b
)

echo Running as Administrator...
echo Starting UE...

powershell -NoProfile -ExecutionPolicy Bypass -File "%~dp0Start_UE.ps1"

endlocal

qtservice code

class PixelStreamServiceTalk : public QtService<QCoreApplication>
{
public:
    PixelStreamServiceTalk(int argc, char** argv)
        : QtService<QCoreApplication>(argc, argv, "PixelStreamingCloudServer")
    {
        const QStringList arguments = QCoreApplication::arguments();
        setServiceDescription("PixelStreamServiceTalk implemented with Qt");
        setServiceFlags(QtServiceBase::CanBeSuspended);
    }

protected:
    void start()
    {
        QSettings settings(QApplication::applicationDirPath() + "/config.ini", QSettings::IniFormat);
        QString scriptPath = settings.value("config/ServiceStart").toString();
        //
        QProcess process;
        process.setProgram("cmd.exe");
        process.setArguments({ "/c", "D:/workplace/UE_2025_QingYunDianTra/trunk/package/InstallUEPlatform/CloudTaskServer/StartServer.bat" });
        process.start();
        process.waitForFinished(-1);
        //
        QFile file("C:/temp/service_running.log");
        file.open(QIODevice::WriteOnly | QIODevice::Append);
        QTextStream stream(&file);
        stream << QDateTime::currentDateTime().toString() << " - Service start.\n" << scriptPath.toLocal8Bit().toStdString().c_str();
        file.close();
    }

    void stop()
    {
        QSettings settings(QApplication::applicationDirPath() + "/config.ini", QSettings::IniFormat);
        QString scriptPath = settings.value("config/ServiceStop").toString();
        //
        QProcess process;
        process.setProgram("cmd.exe");
        process.setArguments({ "/c", "D:/workplace/UE_2025_QingYunDianTra/trunk/package/InstallUEPlatform/CloudTaskServer/StopServer.bat" });
        process.start();
        process.waitForFinished(-1);
        //
        QFile file("C:/temp/service_running.log");
        file.open(QIODevice::WriteOnly | QIODevice::Append);
        QTextStream stream(&file);
        stream << QDateTime::currentDateTime().toString() << " - Service stop.\n" << scriptPath.toLocal8Bit().toStdString().c_str();
        file.close();
    }
private:
};

[JonB]

@mirro

• How do you know that cmd /c ... definitely accepts a Windows path with forward rather then native backslashes in it?
• Have you tried the exact cmd /c D:/workplace/... from a Command Prompt?
• Have you verified that the command exits so that your waitForFinished() will actually return?
• You should put in all error checking for your QProcess, including signals like started(), finished() & errorOccurred(), as well as reading back any and all output which might be being sent to either stdout or stderr with the appropriate QProcess methods, as this is what Windows does at least sometimes.
• You might check the Windows Event Log for any messages about this service start attempt.

[mirro]

@JonB
The QProcess test will fail when executing .bat file in the service start method of QService,but The QProcess test will succeed when executing .bat file in the Main function.

[jsulm]

@mirro Please post code as text, not pictures.
In your code you're not waiting after calling exec() and you did not add any error handling as @JonB suggested. And did you check Windows logs as it was also suggested?
You should use startDetached instead of execute if you're not waiting for the process to finish. command variable should be a QStringList, not QString.