How to Quit current Powershell IE COM session using Try/Catch/Finally

Question

Looking to terminate IE COM Object browser sessions at the end of my script, in my Finally{} statement.

I would think it be as simple as:

Finally{
    $ie.Quit()
}

But its not. the $ie object is unreachable at this stage in the script and no methods can be called on it. Anyone know why this is? Did the $ie object go out of scope?

I have defined the $ie object earlier, before my Try{} statement:

$ie = New-Object -COMObject InternetExplorer.Application

Try{...}

But I dont actually Navigate() until inside the Try{} statement:

$ie = New-Object -COMObject InternetExplorer.Application

    Try{
         $ie.navigate("http://www.allregs.com/tpl/Main.aspx")

}

Then I have my catch{} statement:

Catch{
   write-host “Exception Message: $($_.Exception.Message)” -ForegroundColor Red    
}

And lastly my Finally{} statement:

Finally{
    $ie.Quit() # 'can't call method on System.ComObject.' Null?
}

Any ideas why I can't Quit() the current $ie process at this stage in the script? Am I missing something? Is there another way to end the current Internet explorer session, without closing ALL of them? Any input welcome. Thanks.

Update: So it appears $IE is unreachable at the end because the code never reaches the part where $ie actually navigates and gets a value. It only gets initialized at the start. In fact, it appears my Invoke-Webrequest requests (which log me in) are what prompt IE to start up and this is why a call to $ie.Quit() does nothing. My question now, is there a way to close IE sessions started using Invoke-Webrequest? -UseBasicParameter works to supress IE from starting up but it also messes up my code in weird ways so this doesn't seem like an option

It isn't clear whether you have the `$ie.Quit()` command in the `try{}` block, the `finally{}` block or both. If both, that's likely a problem... — Charlie Joynt, May 03 '16 at 22:30
I think you'll need to update your code samples to include more of what you are doing, including how you are using the `Invoke-WebRequest` cmdlet. — Charlie Joynt, May 04 '16 at 15:45
see my other post @ [link](http://stackoverflow.com/questions/37028778/how-to-close-ie-sessions-opened-by-invoke-webrequest?noredirect=1#comment61611849_37028778) — Eric Furspan, May 04 '16 at 15:47

Charlie Joynt · Answer 1 · 2016-05-04T16:01:29.717

1

You don't really need the finally{} block unless there is something in the catch{} block that would terminate the script/function at that point. If the script/function is able to carry on after the try{}catch{}, then you can just call $ie.Quit():

$ie = New-Object -COMObject InternetExplorer.Application

try {
  $ie.navigate("http://www.allregs.com/tpl/Main.aspx")
}
catch {
  Write-Host “Exception Message: $($_.Exception.Message)” -ForegroundColor Red    
}

$ie.Quit()

Update

In light of the additional information in the question, I don't think that try-catch-finally has anything to do with the actual problem here, so I guess the answer to the title question is that as long as $ie is still a valid application object, the .Quit() method will still work in a finally{} block.

edited May 04 '16 at 16:01

answered May 03 '16 at 22:29

Charlie Joynt

4,411
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Isn't the finally{} block necessary for cleanup? ref: [Why is try {…} finally {…} good; try {…} catch{} bad?](http://stackoverflow.com/questions/128818/why-is-try-finally-good-try-catch-bad?rq=1) – Eric Furspan May 04 '16 at 02:47
This is probably now beside the point for this question, but that link was about why using `catch{}` with *nothing* in the catch block is bad. In this case we are handling the Exception, albeit only with a `Write-Host` notification. – Charlie Joynt May 04 '16 at 08:18
Ah okay. I will try to see if I can do without finally block. – Eric Furspan May 04 '16 at 09:59
Updated my post. $ie was not able to quit() because it was only initialized at the start and the code never reached the navigate(). In fact, it was the Invoke-WebRequests (that log my script in) which prompted IE to start and now I need to figure how to close them. – Eric Furspan May 04 '16 at 13:03
OK, so this is a red herring. Before I stop thinking about try-catch I'd just suggest that IF you are doing lots of things in a single try{}` block, maybe you should use multiple `try{} catch{}` constructions around those commands that might throw a terminating error, or even a single `trap{}` at the top instead. I'll let you read up on that yourself. ;-) – Charlie Joynt May 04 '16 at 15:41
Just saw your other question. I would DEFINITELY look to limit the `try{}` block to just those lines where you need it, else you still have a bit of work on your hands working out which line threw an error. – Charlie Joynt May 04 '16 at 15:57

How to Quit current Powershell IE COM session using Try/Catch/Finally

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