Category Archives: PowerShell

Powershell OpenFileDialog is not showing up

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Recently I was writing scripts that should run on a Windows 7 machine. One task was to select a file and read it. So I used the usual snippet:

$OpenFileDialog = New-Object System.Windows.Forms.OpenFileDialog
[void]$OpenFileDialog.ShowDialog()

I ran the script from PowerShell ISE during development and everything worked fine but when the users executed the script, the file dialog did not open up. Then I came across this page here and it said ShowHelp solves the problem. I changed the script to:

$OpenFileDialog = New-Object System.Windows.Forms.OpenFileDialog
$OpenFileDialog.ShowHelp = $true
[void]$OpenFileDialog.ShowDialog()

I am not sure why, but this solved the problem and did not cause any other side effect. I am wondering what ShowHelp actual does because it seems to have no visible effect.

PowerShell – wait for completion of external process

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Often when working with PowerShell you want to start an external process and wait for its completion. An example of this might look like this:

Write-Host "Show before starting Notepad"

Notepad.exe

Write-Host "Show after closing Notepad"

But this script prints the second line directly after starting notepad. There are several solutions possible, but this one has proved very useful.

Write-Host "Show before starting Notepad"

Notepad.exe | Out-Null

Write-Host "Show after closing Notepad"

Simply add Out-Null after the invocation of notepad and PowerShell will wait until it continues executing the script.