I'm having trouble with using the Dispose() method in PowerShell when I've set up an object inside a try-finally block. The usual practice is to call Dispose() in the finally block to ensure the object is cleaned up, but if the object creation itself throws an exception, that leads to an issue since the object isn't created and calling Dispose() on a null value causes an error. I considered creating the object outside of the try block, but that adds complexity with additional try blocks or checks. I was wondering if there's a simple way to initialize the object with a placeholder that doesn't need disposal. Does anyone know if such a no-op object exists in .NET or can suggest better practices to avoid this problem?
1 Answer
One approach you can try is checking how the .NET object can be created. If the object allows for additional arguments after creation, you can set it up like this:
try {
$obj = [some.net.class]::new()
$obj.connect($dbstring)
}
finally {
$obj.Dispose()
}
Alternatively, you can use a flag to track whether the object was created:
$objCreated = $false
try {
$obj = ... #create object
$objCreated = $true
}
finally {
if ($objCreated) {
$obj.Dispose()
}
}
Or simply check if the object is not null and has a Dispose method before calling it:
try {
$obj = ... #create object
}
finally {
if (($null -ne $obj) -and (($obj | Get-Member -MemberType Method).Name -Contains 'Dispose')) {
$obj.Dispose()
}
}
Those methods sound way better and more efficient!