Alternative to time delay while installing exe through 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.

1. I've created two method signatures (the bit in the here-string); one for each function we're calling.
2. I use those signatures to create corresponding types. Again, one for each method.
3. 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.
4. Behind the scenes, PowerShell adds references to the System and System.Runtime.InteropServices so no need to worry about those.
5. I create my string size ($nChars), window pointer ($handle), and window title buffer ($Buff)
6. 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!