对扩展属性的 powershell 调用静默失败（通过 Update-TypeData 添加）

Question

我的问题是：

• 为什么这个错误没有被抛出到代码中？
• 如何让错误被抛出到代码中？

• 我在哪里/我怎么能自己解决这个问题？ / 这个“特性”的文档在哪里？

  Function demo_problem
  {
      describe_global_error_variable
      $ret_value = "be loud please".extended_property
      write-host "returned a value=[$ret_value]."
      describe_global_error_variable
  }
  
  
  Function describe_global_error_variable
  {
      $cnt = $Error.Count
      write-host "`$Error .Count=[$($cnt)]." 
      $i=0
      while ($i -lt $cnt) {
          write-host "`$Error[$i].Exception.Message=[$($Error[$i].Exception.Message)]"
          $i += 1
          }
  }
  
  $script_block_throws = { 
          write-host "at beginning of script_block for script_block_throws.  `$this=[$this]."
          1/0
          return $true
          write-host "at end of script_block for script_block_throws.  `$this=[$this]."
      }
  
  $script_block_try_catch_throw = { 
          write-host "at beginning of script_block for script_block_try_catch_throw.  `$this=[$this]."
          try
          {
              1/0
              return $true
          }
          catch [Exception]{
              write-host "script_block_try_catch_throw caught an exception"
              throw "caught an exception" 
          }
          return $false
          write-host "at end of script_block for script_block_try_catch_throw.  `$this=[$this]."
      }
  
  try {
      Update-TypeData -Value:$script_block_throws -TypeName:System.String -MemberName:extended_property -Force -MemberType:ScriptProperty 
      demo_problem
      Update-TypeData -Value:$script_block_try_catch_throw -TypeName:System.String -MemberName:extended_property -Force -MemberType:ScriptProperty 
      demo_problem
  }
  catch [Exception]{
      write-host "exception got thrown out of the script block...."   
  }
  
  <#
  PS C:\ .\powershell_call_to_extended_property_fails_silently.ps1
  $Error .Count=[0]. \
  at beginning of script_block for script_block_throws.  $this=[be loud please].
  returned a value=[].
  $Error .Count=[1]. \
  $Error[0].Exception.Message=[Attempted to divide by zero.]
  $Error .Count=[1]. \
  $Error[0].Exception.Message=[Attempted to divide by zero.]
  at beginning of script_block for script_block_try_catch_throw.  $this=[be loud please].
  script_block_try_catch_throw caught an exception
  returned a value=[].
  $Error .Count=[3]. \
  $Error[0].Exception.Message=[caught an exception]
  $Error[1].Exception.Message=[Attempted to divide by zero.]
  $Error[2].Exception.Message=[Attempted to divide by zero.]
  #>
  

Answer 1

PowerShell 团队告诉我，属性的异常总是被屏蔽，因为在格式化和输出过程中会大量使用属性。 ScriptMethod 不会屏蔽异常。虽然从调试的角度来看这是不幸的，但通常属性不应该做的不仅仅是获取和设置状态。我还要补充一点，.NET 开发人员不希望抛出属性。

如果您不喜欢这种行为，请随时在http://connect.microsoft.com 网站上提交问题。我知道至少有一个 PowerShell 开发人员不喜欢异常是 always 隐藏的，即即使在格式化操作之外。对此有一些客户意见可以帮助开发人员提出改变行为的理由 - 至少在严格模式下是这样。

Answer 2

我真的认为这是某种范围问题或错误。我能够很容易地复制它。我能够解决问题的唯一方法是通过一种变通方法，如下所示：

Update-TypeData -Value:$script_block_try_catch_throw -TypeName:System.String -MemberName:extended_property -Force -MemberType:ScriptProperty -ErrorAction Stop
demo_problem
if($error[0].Exception.Message -eq "caught an exception")
{
    throw "I only exist to trigger the catch block"
}

我什至试过这个都没用：

Update-TypeData -Value:{try{&$script_block_try_catch_throw}catch{throw "Error!"}} -TypeName:System.String -MemberName:extended_property -Force -MemberType:ScriptProperty -ErrorAction Stop

我很惊讶这不起作用。