excel - 获取 Excel 元数据

Question

我正在使用 this PowerShell script这显示了如何获取 Excel 文件元数据:

$excel = New-Object -ComObject Excel.Application
$excel.Visible = $false
$workbook = $excel.Workbooks.Open("C:\test\excel.xls")
$binding = "System.Reflection.BindingFlags" -as [type]
foreach ($property in $workbook.BuiltInDocumentProperties) {
    $pn = [System.__ComObject].InvokeMember("name", $binding::GetProperty, $null, $property, $null)
    trap [System.Exception] {
        Write-Host -Foreground blue "Value not found for $pn"
        continue
    }
    "$pn`: " + [System.__ComObject].InvokeMember("value", $binding::GetProperty, $null, $property, $null)
}
$excel.Quit()

有人可以帮忙吗:

对于脚本行:

[System.__ComObject].InvokeMember("name", $binding::GetProperty, $null, $property, $null)

我的理解方式[System.__ComObject]表示 foreach 中返回对象的“类型”环形。

你能解释一下为什么吗

[System.__ComObject]$property.InvokeMember("name", $binding::GetProperty, $null, $property, $null)

导致“陷阱”被触发？不是 foreach 中返回的“对象”吗？循环，$property ?

另外，我找到了this Excel VBA code获得“最后保存时间”:

Function LastModified() as Date
    LastModified = ActiveWorkbook.BuiltinDocumentProperties("Last Save Time")
End Function

此代码适用于 Excel VBA。那么为什么这个等效的 PowerShell 代码不起作用:

$lst = $workbook.BuiltinDocumentProperties("Last Save Time")
[System.__ComObject]$lst.InvokeMember("value", $binding::GetProperty, $null, $property, $null)

Answer 1

来自 about_Trap documentation :

When a terminating error occurs that is not handled in another way in a script or command, Windows PowerShell checks for a Trap statement that handles the error. If a Trap statement is present, Windows PowerShell continues running the script or command in the Trap statement.

您在此处的代码逻辑与 foreach 中的代码逻辑不同。环形。第一行也与 VBA 示例不同，但该部分应该可以正常工作。

$lst = $excel.ActiveWorkbook.BuiltinDocumentProperties("Last save time") # like in VBA
$lst = $workbook.BuiltinDocumentProperties("Last Save Time")             # also fine

[System.__ComObject].InvokeMember("value", $binding::GetProperty, $null, $lst, $null)