SAPIEN Solutions

If you came from the VBScript world you may be missing a few old friends in PowerShell. Because Powershell is a management console, it lacks a GUI unless you create one using Windows forms. Things will change a bit in PowerShell v2.0 but for now let’s stick with what we have.  If you really need a message box, ala VBScript, then simply call it from PowerShell.  All you need to do is use the [microsoft.visualbasic.interaction] class and the MsgBox method.

Before you can use it, you will likely need to load the .NET assembly:

PS C:\> [reflection.assembly]::loadwithpartialname(”microsoft.visualbasic”) | Out-Null

Once loaded you can call a message box as easy as this:

PS C:\> [microsoft.visualbasic.interaction]::MsgBox(”Hello everyone”)
Ok
PS C:\>

As you can see it is a barebones message box.

The MsgBox method supports all the things you remember from VBScript like different buttons, a title and icons. Valid button choices include: OkOnly, OkCancel, AbortRetryIgnore, YesNoCancel, YesNo, RetryCancel. There are a few other options but these are the ones you are most likely to use. Valid icons include: Critical, Question, Exclamation, Information.

Here is a function to create a message box and sample code that demonstrates it.

   1: Function Show-Msgbox {

   2:   Param([string]$message=$(Throw "You must specify a message"),

   3:       [string]$button="okonly",

   4:       [string]$icon="information",

   5:       [string]$title="Message Box"

   6:      )

   7:

   8: # Buttons: OkOnly, OkCancel, AbortRetryIgnore, YesNoCancel, YesNo, RetryCancel

   9: # Icons: Critical, Question, Exclamation, Information

  10:

  11:   [reflection.assembly]::loadwithpartialname("microsoft.visualbasic") | Out-Null

  12:

  13:   [microsoft.visualbasic.interaction]::Msgbox($message,"$button,$icon",$title)

  14:

  15:  }

  16:

  17: $rc=Show-Msgbox -message "Do you know what you're doing?" `

  18: -icon "exclamation" -button "YesNoCancel" -title "Hey $env:username!!"

  19:

  20: Switch ($rc) {

  21:  "Yes" {"I hope your resume is up to date."}

  22:  "No" {"Wise move."}

  23:  "cancel" {"When in doubt, punt."}

  24: }

  25:

If you execute this you should expect a result like this:

The MsgBox method will write the name of the clicked button to the pipeline. This allows me to save the MsgBox results to a variable and use a Switch construct to take action based on the value:

$rc=Show-Msgbox -message “Do you know what you’re doing?” `
-icon “exclamation” -button “YesNoCancel” -title “Hey $env:username!!”

Switch ($rc) {
“Yes” {”I hope your resume is up to date.”}
“No” {”Wise move.”}
“cancel” {”When in doubt, punt.”}
}

You’re probably thinking, “This is great but where’s my Inputbox?” Don’t worry.  It’s coming assuming you don’t figure it out on your own.

Technorati Tags: function, MsgBox, powershell, Switch, VBScript

Tags: function, MsgBox, powershell, Switch, VBScript

This entry was posted on Tuesday, August 12th, 2008 at 11:00 am and is filed under VBScript, Windows PowerShell. You can follow any responses to this entry through the RSS 2.0 feed. You can leave a response, or trackback from your own site.