PowerShell使用.NET4.8 FlaUI时找不到AsButton方法求助

我在PowerShell脚本中尝试调用FlaUI的AsButton方法，但运行时提示找不到该方法。该脚本用于打开计算器并依次点击“Five”“Plus”“Nine”“Equals”按钮，最后获取计算结果。

脚本代码如下：

[System.Reflection.Assembly]::LoadFrom("c:\Temp\FlaUI.Core.dll")
[System.Reflection.Assembly]::LoadFrom("c:\Temp\FlaUI.UIA3.dll")

$calc = [Diagnostics.Process]::Start('calc')
#wait for the UI to appear
$null = $calc.WaitForInputIdle(5000)
sleep -s 2
$calcWindowId = ((Get-Process).where{ $_.MainWindowTitle -eq 'Calculator' })[0].Id

$uia = New-Object FlaUI.UIA3.UIA3Automation
$cf = $uia.ConditionFactory
$btnCondition = $cf.ByControlType('Button')
$desktop = $uia.GetDesktop()
$calc = $desktop.FindFirstDescendant($uia.ConditionFactory.ByProcessId($calcWindowId))
$calc.FindFirstDescendant($btnCondition.And($cf.ByName('Five'))).AsButton().Click()
$calc.FindFirstDescendant($btnCondition.And($cf.ByName('Plus'))).AsButton().Click()
$calc.FindFirstDescendant($btnCondition.And($cf.ByName('Nine'))).AsButton().Click()
$calc.FindFirstDescendant($btnCondition.And($cf.ByName('Equals'))).AsButton().Click()
$calc.FindFirstDescendant($cf.ByAutomationId('CalculatorResults')).Properties.Name.Value

运行后抛出如下异常：

Method invocation failed because [FlaUI.Core.AutomationElements.AutomationElement] does not contain a method named 'AsButton'.
At C:\Temp\test2.ps1:15 char:1
+ $calc.FindFirstDescendant($btnCondition.And($cf.ByName('Five'))).AsBu ...
+ ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
    + CategoryInfo          : InvalidOperation: (:) [], RuntimeException
    + FullyQualifiedErrorId : MethodNotFound
 
Method invocation failed because [FlaUI.Core.AutomationElements.AutomationElement] does not contain a method named 'AsButton'.
At C:\Temp\test2.ps1:16 char:1
+ $calc.FindFirstDescendant($btnCondition.And($cf.ByName('Plus'))).AsBu ...
+ ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
    + CategoryInfo          : InvalidOperation: (:) [], RuntimeException
    + FullyQualifiedErrorId : MethodNotFound
 
Method invocation failed because [FlaUI.Core.AutomationElements.AutomationElement] does not contain a method named 'AsButton'.
At C:\Temp\test2.ps1:17 char:1
+ $calc.FindFirstDescendant($btnCondition.And($cf.ByName('Nine'))).AsBu ...
+ ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
    + CategoryInfo          : InvalidOperation: (:) [], RuntimeException
    + FullyQualifiedErrorId : MethodNotFound
 
Method invocation failed because [FlaUI.Core.AutomationElements.AutomationElement] does not contain a method named 'AsButton'.
At C:\Temp\test2.ps1:18 char:1
+ $calc.FindFirstDescendant($btnCondition.And($cf.ByName('Equals'))).As ...
+ ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
    + CategoryInfo          : InvalidOperation: (:) [], RuntimeException
    + FullyQualifiedErrorId : MethodNotFound

我使用的是.NET4.8版本的FlaUI，已添加其他相关DLL，网上有同功能的代码可以正常运行，但我的脚本就是找不到AsButton方法，请问这是什么原因？

内容的提问来源于stack exchange，提问作者StackDos