非交互模式执行PowerShell脚本时出现Unsupported Pattern异常

我想用PowerShell静默卸载程序，流程是通过Winget启动卸载，再用UIAutomation点击卸载确认按钮。逐行交互执行脚本时多次测试都正常，但从文件运行或粘贴整个脚本块到PowerShell时，出现以下错误：

Exception calling "GetCurrentPattern" with "1" argument(s): "Unsupported Pattern."

试过在每个操作后加Start-Sleep排查，没用；也换过不同PowerShell版本、系统上下文运行脚本，问题依旧。完整脚本如下：

#import required assemblies
Add-Type -AssemblyName UIAutomationClient
Add-Type -AssemblyName UIAutomationTypes

#find and run winget (script runs in system context and cant find winget, but directly referencing .exe works)
$winget = "$env:programfiles\WindowsApps\Microsoft.DesktopAppInstaller_*_x64__8wekyb3d8bbwe\winget.exe"
&$winget uninstall dropbox --Disable-Interactivity

#find drobbox uninstaller process
$DBUninstallProc = (Get-Process | Where-Object {$_.ProcessName -eq 'Au_'})
#wait for GUI to load
$null = $DBUninstallProc.WaitForInputIdle(5000)

#get root element
$root = [Windows.Automation.AutomationElement]::RootElement

#Create a PropertyCondition used to grab the Uninstaller Window
$GetDBWindowCondition = New-Object Windows.Automation.PropertyCondition([Windows.Automation.AutomationElement]::ProcessIdProperty, $DBUninstallProc.Id)

#Get the Uninstaller window
$DBUninstallerUI = $root.FindFirst([Windows.Automation.TreeScope]::Children, $GetDBWindowCondition)

#Find the uninstall button
$UninstallButtonCondition = New-Object Windows.Automation.PropertyCondition([Windows.Automation.AutomationElement]::NameProperty, "Uninstall")
$button = $DBUninstallerUI.FindFirst([Windows.Automation.TreeScope]::Descendants, $UninstallButtonCondition)

#Click the uninstall button
$button.GetCurrentPattern([Windows.Automation.InvokePattern]::Pattern) #.Invoke();

问题根源是批量运行时，UI元素还未完全初始化就被脚本尝试访问，WaitForInputIdle无法保证UI控件的Pattern已经就绪。可以从以下几点优化：

• 循环等待窗口和控件就绪
  不要只等待进程空闲，要循环检查窗口和按钮元素是否存在，以及控件是否支持InvokePattern：

  # 等待卸载器窗口出现
  $DBUninstallerUI = $null
  while (-not $DBUninstallerUI) {
      Start-Sleep -Milliseconds 500
      $DBUninstallerUI = $root.FindFirst([Windows.Automation.TreeScope]::Children, $GetDBWindowCondition)
  }
  
  # 等待Uninstall按钮出现并确认支持InvokePattern
  $button = $null
  $invokePattern = $null
  while (-not $invokePattern) {
      Start-Sleep -Milliseconds 500
      $button = $DBUninstallerUI.FindFirst([Windows.Automation.TreeScope]::Descendants, $UninstallButtonCondition)
      if ($button) {
          try {
              $invokePattern = $button.GetCurrentPattern([Windows.Automation.InvokePattern]::Pattern)
          }
          catch {
              # 控件还未就绪，继续等待
              $button = $null
          }
      }
  }
  
  # 执行点击
  $invokePattern.Invoke()
  

• 改进进程查找逻辑
  原脚本中Get-Process | Where-Object {$_.ProcessName -eq 'Au_'}可能匹配多个进程，或者进程还未启动就查找，改成循环查找直到进程存在：

  $DBUninstallProc = $null
  while (-not $DBUninstallProc) {
      Start-Sleep -Milliseconds 500
      $DBUninstallProc = Get-Process -Name 'Au_' -ErrorAction SilentlyContinue
  }
  

• 调整Winget执行方式
  使用Start-Process并等待Winget启动卸载器后再继续，避免脚本超前执行：

  Start-Process -FilePath $winget -ArgumentList "uninstall dropbox --Disable-Interactivity" -Wait -NoNewWindow
  

整合后的完整脚本：

# 导入所需程序集
Add-Type -AssemblyName UIAutomationClient
Add-Type -AssemblyName UIAutomationTypes

# 定位Winget路径（避免通配符匹配多个版本）
$wingetPath = Get-ChildItem -Path "$env:programfiles\WindowsApps\Microsoft.DesktopAppInstaller_*_x64__8wekyb3d8bbwe\winget.exe" | Select-Object -Last 1 -ExpandProperty FullName
if (-not $wingetPath) {
    Write-Error "未找到Winget可执行文件"
    exit 1
}

# 启动Winget卸载Dropbox并等待操作完成
Start-Process -FilePath $wingetPath -ArgumentList "uninstall dropbox --Disable-Interactivity" -Wait -NoNewWindow

# 循环查找Dropbox卸载器进程
$DBUninstallProc = $null
while (-not $DBUninstallProc) {
    Start-Sleep -Milliseconds 500
    $DBUninstallProc = Get-Process -Name 'Au_' -ErrorAction SilentlyContinue
}

# 等待进程进入空闲状态
$null = $DBUninstallProc.WaitForInputIdle(5000)

# 获取UI自动化根元素
$root = [Windows.Automation.AutomationElement]::RootElement

# 创建卸载窗口查找条件（按进程ID匹配）
$windowCondition = New-Object Windows.Automation.PropertyCondition([Windows.Automation.AutomationElement]::ProcessIdProperty, $DBUninstallProc.Id)

# 循环等待卸载窗口出现
$uninstallWindow = $null
while (-not $uninstallWindow) {
    Start-Sleep -Milliseconds 500
    $uninstallWindow = $root.FindFirst([Windows.Automation.TreeScope]::Children, $windowCondition)
}

# 创建卸载按钮查找条件（按名称匹配）
$buttonCondition = New-Object Windows.Automation.PropertyCondition([Windows.Automation.AutomationElement]::NameProperty, "Uninstall")

# 循环等待按钮就绪并获取InvokePattern
$invokePattern = $null
while (-not $invokePattern) {
    Start-Sleep -Milliseconds 500
    $button = $uninstallWindow.FindFirst([Windows.Automation.TreeScope]::Descendants, $buttonCondition)
    if ($button) {
        try {
            $invokePattern = $button.GetCurrentPattern([Windows.Automation.InvokePattern]::Pattern)
        }
        catch {
            # 控件未完全初始化，重置按钮对象继续等待
            $button = $null
        }
    }
}

# 执行按钮点击操作
$invokePattern.Invoke()

内容的提问来源于stack exchange，提问作者jonathan