QT Terminate Browser Process

Dusk Le

I have a task that we need to open and close a specific Window Browser by the QT app.
Do you have any solution? Help me, please.

JonB

@Dusk-Le
What is/do you mean by "a specific Window Browser" that you "open and close", this is not clear.

Dusk Le

Example: I open a new window browser and close this window browser after 3 seconds via the QT app. Is that feasible?

JonB

@Dusk-Le
Probably/possibly, but what is "a new window browser"? I have no idea. What code do you write to do this? Then we can tell you whether/how to "close it".

Dusk Le

#include <QCoreApplication>
#include "QProcess"
#include "QThread"

int main(int argc, char *argv[])
{
QCoreApplication a(argc, argv);
QProcess process;
process.start("C:/Program Files/Google/Chrome/Application/Chrome.exe", QStringList() << "--new-window" << "google.com");
QThread::msleep(3000);
process.close(); //cannot close this browser process in here
return a.exec();
}

You can see this code, I can open but I cannot close it. I cannot find out the solution.

JonB

@Dusk-Le
This is the first time you have shown you are running a QProcess! That is what I needed to know.

So you can use QProcess::terminate() for choice, if that does not work then QProcess::kill().

However these --- particularly kill() --- are "not nice to do".

Also there is no guarantee that the process initiated from Qt via QProcess is actually the same process as opens that window. Chrome may have internals which create its own processes, or it might use a single process which has multiple windows open. I don't know, you'll have to try it and see.

If it turns out you need to find the required process to kill, e.g. by its "name" perhaps for that window, you would have to look at Windows code for EnumProcesses etc.

Finally, there might be an alternative. Instead of asking an external Chrome process to run to display this window/page, Qt has QtWebEngine (webenginewidgets). That is a Qt widget using the chromium engine to display web pages. If you changed over to that you would have more control than via running an external Chrome.exe process.

Dusk Le

This job needs to run external Chrome.exe. That is the big problem.
I try to use kill() or terminate(), but it doesn't work too.
Another person told me that making the browser process is the child of the cmd process. Kill cmd process will kill browser process too. But I don't know how to try this solution.

JonB

@Dusk-Le
You are already spawning the Chrome.exe as a child of your Qt app. If QProcess::kill() does not work you have a problem. Quite possibly because like I suggested the original QProcess you spawn is not kept as the process for the resulting opened window, due to Chrome internals.

Start by Googling for, say, kill one chrome process or kill one chrome window, to see how difficult/easy this is.

Then if you don't kind a better way, start with the following:

Keep your process.start(). You might want to add qDebug() << process.processId(); after it, for use below.
Comment out msleep/close/kill().
Let the Chrome run up its window/page/tab.
Go into Windows Task Manager.
Look through all the (scary number of!) running Chrome processes. (Hint: You may want to View > Select Columns... > find and check the Command Line column.)
By experimenting with End Process them, find which one (or ones?) you need to terminate to achieve the right one for your window.
Then use Windows EnumProcesses etc. to determine how you can find that desired process(es), and Windows calls to kill it.