Alternative to time delay while installing exe through PowerShell? - powershell

Question

I have a software exe which I am trying to install via PowerShell. It's working fine. I am using SendKeys to navigate through the installation GUI. I have given delay between two SendKeys commands, because software takes some time between two steps, but that installation time varies from computer to computer.
My question is how can I bypass this time delay dependency in SendKeys? I have tried AppActivate but its of no use for me. Is there any alternative to delay?

Answer 1

Sure.
I've converted Nitesh's C# function to a Powershell script
$signature_user32_GetForegroundWindow = #"
[DllImport("user32.dll")]
public static extern IntPtr GetForegroundWindow();
"#
$signature_user32_GetWindowText = #"
[DllImport("user32.dll")]
public static extern int GetWindowText(IntPtr hWnd, StringBuilder text, int count);
"#
$foo = `
Add-Type -MemberDefinition $signature_user32_GetForegroundWindow `
-Name 'user32_GetForegroundWindow' `
-Namespace 'Win32' `
-PassThru
$bar = `
Add-Type -MemberDefinition $signature_user32_GetWindowText `
-Name 'user32_GetWindowText' `
-Namespace 'Win32' `
-Using System.Text `
-PassThru
[int]$nChars = 256
[System.IntPtr] $handle = New-object 'System.IntPtr'
[System.Text.StringBuilder] $Buff = New-Object 'System.Text.StringBuilder' `
-ArgumentList $nChars
$handle = $foo::GetForegroundWindow()
$title_character_count = $bar::GetWindowText($handle, $Buff, $nChars)
If ($title_character_count -gt 0) { Write-Output $Buff.ToString() }
There is a lot going on here. Lemme explain a little of what I did.
I've created two method signatures (the bit in the here-string); one for each function we're calling.
I use those signatures to create corresponding types. Again, one for each method.
For the GetWindowType (which passes the title back in a string and needs a reference to System.Text), I pass in the System.Text namespace in the -Using parameter.
Behind the scenes, PowerShell adds references to the System and System.Runtime.InteropServices so no need to worry about those.
I create my string size ($nChars), window pointer ($handle), and window title buffer ($Buff)
I call the functions through the type-pointer: $foo... and $bar...
Here is what I get when I run all this...
Whenever I have to call the Windows API (which isn't really my thing), I reference the following two articles:
PowerShell P/Invoke Walkthrough
Use PowerShell to Interact with the Windows API: Part 1
I hope this helps!