屏幕锁定时未显示PowerShell表单

问题描述

我正在使用PowerShell表单来提示用户关闭Adobe Reader，以便可以对其进行升级。它是通过SCCM执行的，因此可以在System上下文中运行。如果用户已登录并且会话处于活动状态，则可以使用该脚本，但是如果锁定了屏幕，则尽管脚本正在运行，但是当我解锁屏幕时，表单不会显示。

我最初使用$Form.ShowDialog()来显示它，但是看到其他一些帖子说它不可靠，所以我切换到[void][System.Windows.Forms.Application]::Run($Form)，但是它仍然不起作用。有人可以帮我解决这个问题吗？

下面是经过精简的脚本，其中仅包含与呈现表单有关的代码。

Add-Type -AssemblyName System.Windows.Forms,System.Drawing
$Font = New-Object System.Drawing.Font('Segoe UI Light',14,[System.Drawing.FontStyle]::Regular)
$FontBold = New-Object System.Drawing.Font('Segoe UI',13,[System.Drawing.FontStyle]::Bold)

Function EndForm
{
    $Timer.Stop();
    $Timer.dispose();
    $Label.dispose();
    $CountdownLabel.dispose();
    $ProgressBar.dispose();
    $OKButton.dispose();
    $Form.Close();
    $Form.dispose();
}

$OnOKClick =
{
    $MsgBoxInput = [System.Windows.Forms.MessageBox]::Show("Are you sure you want to close and uninstall Adobe Reader Now?","Confirm Adobe Reader Removal","YesNo","Warning")
    If ($MsgBoxInput -eq "Yes") {EndForm}
}

$Script:Countdown = 3600
$OKToolTip = "Click OK to close and uninstall Adobe Reader Now"
$CountdownSubtitle = "Adobe Reader will close and uninstall in"

$Label = New-Object System.Windows.Forms.Label
$Label.AutoSize = $False
$Label.Height = 120
$Label.Width = 630
$Label.Font = $Font
$Label.BackColor = "White"
$Label.ForeColor = "#4D4C5C"
$Label.Location = New-Object System.Drawing.Size(52,180)
$Label.Text = "Your computer will soon be upgraded to newer versions of Windows 10 and Office 365. In order to succeed,the upgrade process requires that Adobe Reader be closed and uninstalled first. It will not be available for use again until after the upgrade has completed."

$CountdownLabel = New-Object System.Windows.Forms.Label
$CountdownLabel.AutoSize = $False
$CountdownLabel.Height = 40
$CountdownLabel.Width = 530
$CountdownLabel.Font = $Font
$CountdownLabel.BackColor = "White"
$CountdownLabel.ForeColor = "#4D4C5C"
$CountdownLabel.Location = New-Object System.Drawing.Size(120,380)

$ProgressBar = New-Object System.Windows.Forms.ProgressBar
$ProgressBar.Location = New-Object System.Drawing.Size(52,340)
$ProgressBar.Size = New-Object System.Drawing.Size(635,35)
$ProgressBar.Style = "Continuous"
$ProgressBar.Maximum = $Script:Countdown
$ProgressBar.Minimum = 0

$OKButton = New-Object System.Windows.Forms.Button
$OKButton.Name = "OK_Button"
$OKButton.Size = New-Object System.Drawing.Size(80,40)
$OKButton.Location = New-Object System.Drawing.Size(330,450)
$OKButton.UseVisualStyleBackColor = $True
$OKButton.Text = "OK"
$OKButton.DataBindings.DefaultDataSourceUpdateMode = 0
$OKButton.Add_Click($OnOKClick)

$ToolTip = New-Object System.Windows.Forms.ToolTip
$ToolTip.IsBalloon = $False 
$ToolTip.InitialDelay = 100 
$ToolTip.ReshowDelay = 200 
$ToolTip.SetToolTip($OKButton,$OKToolTip) 

$Form = New-Object System.Windows.Forms.Form
$Form.Text = "Contoso LLC"
$Form.Font = $Font
$Form.Width = 770
$Form.Height = 580
$Form.MinimizeBox = $False
$Form.MaximizeBox = $False
$Form.ControlBox = $False
$Form.ShowIcon = $False
$Form.WindowState = "normal"
$Form.FormBorderStyle = "Fixed3D"
$Form.ShowInTaskbar = $True
$Form.StartPosition = "CenterScreen"
$Form.Topmost = $True
$Form.Controls.Add($ProgressBar)
$Form.Controls.Add($Label)
$Form.Controls.Add($CountdownLabel)
$Form.Controls.Add($OKButton)

$Timer = New-Object System.Windows.Forms.Timer
$Timer.Interval = 1000
$Timer.Add_Tick(
{
    If ($Script:Countdown -eq 0) {EndForm}

    $ProgressBar.Value  = $Script:Countdown
    $TimeRemain = New-Timespan -Seconds $Script:Countdown
    $HrsRemain = $TimeRemain.Hours
    $MinsRemain = $TimeRemain.Minutes
    $SecsRemain = $TimeRemain.Seconds

    If ($HrsRemain -ge 2) {$HrsText = "$HrsRemain hours"}
    If ($HrsRemain -eq 1) {$HrsText = "$HrsRemain hour"}
    If ($MinsRemain -ge 2) {$MinsText = "$MinsRemain minutes"}
    If ($MinsRemain -eq 1) {$MinsText = "$MinsRemain minute"}
    If ($SecsRemain -ge 2) {$SecsText = "$SecsRemain seconds"}
    If ($SecsRemain -eq 1) {$SecsText = "$SecsRemain second"}

    $CountdownLabel.Text  = "$CountdownSubtitle $HrsText $MinsText $SecsText"

    If ($HrsRemain -ge 1 -And $MinsRemain -eq 0) {$CountdownLabel.Text = "$CountdownSubtitle $HrsText $SecsText"}
    If ($HrsRemain -eq 0) {$CountdownLabel.Text = "$CountdownSubtitle $MinsText $SecsText"}
    If ($HrsRemain -eq 0 -And $MinsRemain -eq 0) {$CountdownLabel.Text = "$CountdownSubtitle $SecsText"}
    $Script:Countdown--
})

$Timer.Start()
[void][System.Windows.Forms.Application]::Run($Form)

解决方法

我决定通过检测登录过程的存在来“解决”此问题，这意味着屏幕已锁定。在这种情况下，我还是要关闭Adobe Reader。