powershell 内置PromptForChoice的替代方案，可在不同主机上提供一致的UI

Posted 2021-05-23

#An alternative to the built-in PromptForChoice providing a consistent UI across different hosts
function Get-Choice {
    [CmdletBinding()]
    Param
    (
        [Parameter(Mandatory=$true,Position=0)]
        $Title,

        [Parameter(Mandatory=$true,Position=1)]
        [String[]]
        $Options,

        [Parameter(Position=2)]
        $DefaultChoice = -1
    )
    if ($DefaultChoice -ne -1 -and ($DefaultChoice -gt $Options.Count -or $DefaultChoice -lt 1)){
        Write-Warning "DefaultChoice needs to be a value between 1 and $($Options.Count) or -1 (for none)"
        exit
    }
    Add-Type -AssemblyName System.Windows.Forms
    Add-Type -AssemblyName System.Drawing
    [System.Windows.Forms.Application]::EnableVisualStyles()
    $script:result = ""
    $form = New-Object System.Windows.Forms.Form
    $form.FormBorderStyle = [Windows.Forms.FormBorderStyle]::FixedDialog
    $form.BackColor = [Drawing.Color]::White
    $form.TopMost = $True
    $form.Text = $Title
    $form.ControlBox = $False
    $form.StartPosition = [Windows.Forms.FormStartPosition]::CenterScreen
    #calculate width required based on longest option text and form title
    $minFormWidth = 100
    $formHeight = 44
    $minButtonWidth = 70
    $buttonHeight = 23
    $buttonY = 12
    $spacing = 10
    $buttonWidth = [Windows.Forms.TextRenderer]::MeasureText((($Options | sort Length)[-1]),$form.Font).Width + 1
    $buttonWidth = [Math]::Max($minButtonWidth, $buttonWidth)
    $formWidth =  [Windows.Forms.TextRenderer]::MeasureText($Title,$form.Font).Width
    $spaceWidth = ($options.Count+1) * $spacing
    $formWidth = ($formWidth, $minFormWidth, ($buttonWidth * $Options.Count + $spaceWidth) | Measure-Object -Maximum).Maximum
    $form.ClientSize = New-Object System.Drawing.Size($formWidth,$formHeight)
    $index = 0
    #create the buttons dynamically based on the options
    foreach ($option in $Options){
        Set-Variable "button$index" -Value (New-Object System.Windows.Forms.Button)
        $temp = Get-Variable "button$index" -ValueOnly
        $temp.Size = New-Object System.Drawing.Size($buttonWidth,$buttonHeight)
        $temp.UseVisualStyleBackColor = $True
        $temp.Text = $option
        $buttonX = ($index + 1) * $spacing + $index * $buttonWidth
        $temp.Add_Click({ 
            $script:result = $this.Text; $form.Close() 
        })
        $temp.Location = New-Object System.Drawing.Point($buttonX,$buttonY)
        $form.Controls.Add($temp)
        $index++
    }
    $shownString = '$this.Activate();'
    if ($DefaultChoice -ne -1){
        $shownString += '(Get-Variable "button$($DefaultChoice-1)" -ValueOnly).Focus()'
    }
    $shownSB = [ScriptBlock]::Create($shownString)
    $form.Add_Shown($shownSB)
    [void]$form.ShowDialog()
    $result
}