3

我的问题是：

  • 为什么这个错误没有被抛出到代码中？
  • 我怎样才能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“功能”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.]
#>
4

2 回答 2

5

PowerShell 团队告诉我的是，属性的​​异常总是被屏蔽，因为在格式化和输出期间属性被大量使用。ScriptMethod 不会屏蔽异常。虽然从调试的角度来看这是不幸的，但属性通常不应该做更多的事情，而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一个属性。

如果您不喜欢这种行为，请随时在http://connect.microsoft.com站点上提交问题。我知道至少有一个 PowerShell 开发人员不喜欢异常总是被隐藏，即即使在格式化操作之外。对此有一些客户输入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。

于 2013-11-04T21:42:59.117 回答
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解决方法，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"
}

我什至试过这个无济于事：

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

我很惊讶那没有用。

于 2013-11-04T03:31:48.413 回答