How to do it...

Perform the following steps:

1. The Get-Member cmdlet is again an indispensable tool when working with .NET classes. Try the following bit of code to list all object methods of the File and Directory objects:

Get-ChildItem | Get-Member -MemberType Methods

1. Execute the following commands:

# Accessing methods
$file = New-TemporaryFile
$parentPath = Split-Path -Path $file.FullName -Parent
$newPath = Join-Path -Path $parentPath -ChildPath newFileName

# With arguments
$file.MoveTo($newPath)
$file.FullName # The MoveTo method is a way of changing the FullName property, which is read-only.

# and without arguments
$file.Delete()

1. Be careful when accessing methods that do not exist, or methods of objects that do not exist. Try to do so now by calling a method that does not exist:

# Careful with empty objects or non-existing methods
# Method does not exist. Throws a terminating MethodNotFound error
$file.DoStuff()

# Object does not exist. Throws an InvokeMethodOnNull exception.
($null).Delete()

1. Execute the following code:

# Finding possible arguments
# CopyTo has two overloads
($file | Get-Member -Name CopyTo).Definition

# A handy shortcut is simply leaving the parentheses off
$file.CopyTo

1. Now execute the following code:

# Performance of .NET calls versus cmdlets
Measure-Command -Expression {
    Get-ChildItem -Recurse -File -Path /
}

Measure-Command -Expression {
    $root = Get-Item -Path /
    $options = [System.IO.EnumerationOptions]::new()
    $options.RecurseSubdirectories = $true
    $root.GetFiles('*', $options)
}

1. Methods may or may not return objects. If they do, Get-Member will display the data type that is returned for each overload:

 # Method calls may or may not return values
$process = Get-Process -Id $PID
$process | Get-Member -Name WaitForExit

# The WaitForExit method has two overloads
# When passing a timeout to WaitForExit, it returns a boolean value indicating if the process
# has exited in the allotted timeout.
$pingProcess = if ($IsWindows)
{
    Start-Process -FilePath ping -ArgumentList 'microsoft.com','-n 10' -PassThru
}
else
{
    Start-Process -FilePath ping -ArgumentList 'microsoft.com','-n 10' -PassThru
}

# Waiting 500ms should return false, since our 10 ICMP request will most likely not be done
if( -not $pingProcess.WaitForExit(500))
{
    Write-Host -ForegroundColor Yellow "Pinging not yet complete..."
}

# The other overload has no return type (void) and will wait indefinitely
$pingProcess.WaitForExit()