使用PowerShell在网页上下载所有PDF

我在网上找到了以下代码，可以在网页上下载所有PDF：

$psPage = Invoke-WebRequest "https://www.pi.infn.it/~rizzo/ingegneria/appunti_fisII_ing_mecc/
"
$urls = $psPage.ParsedHtml.getElementsByTagName("A") | ? {$_.href -like "*.pdf"} | Select-Object -ExpandProperty href

$urls | ForEach-Object {Invoke-WebRequest -Uri $_ -OutFile ($_ | Split-Path -Leaf)}

但是PS给了我一个错误：

Invoke-WebRequest : The response content cannot be parsed because the Internet Explorer engine is not
available, or Internet Explorer's first-launch configuration is not complete. Specify the UseBasicParsing
parameter and try again.
At C:\Users\Raffaele\Desktop\Nuova cartella\a.ps1:1 char:11
+ $psPage = Invoke-WebRequest "https://www.pi.infn.it/~rizzo/ingegneria ...
+           ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
    + CategoryInfo          : NotImplemented: (:) [Invoke-WebRequest], NotSupportedException
    + FullyQualifiedErrorId : WebCmdletIEDomNotSupportedException,Microsoft.PowerShell.Commands.InvokeWebReq
   uestCommand

You cannot call a method on a null-valued expression.
At C:\Users\Raffaele\Desktop\Nuova cartella\a.ps1:2 char:1
+ $urls = $psPage.ParsedHtml.getElementsByTagName("A") | ? {$_.href -li ...
+ ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
    + CategoryInfo          : InvalidOperation: (:) [], RuntimeException
    + FullyQualifiedErrorId : InvokeMethodOnNull

Split-Path : Cannot bind argument to parameter 'Path' because it is null.
At C:\Users\Raffaele\Desktop\Nuova cartella\a.ps1:4 char:66
+ ... h-Object {Invoke-WebRequest -Uri $_ -OutFile ($_ | Split-Path -Leaf)}
+                                                        ~~~~~~~~~~~~~~~~
    + CategoryInfo          : InvalidData: (:) [Split-Path], ParameterBindingValidationException
    + FullyQualifiedErrorId : ParameterArgumentValidationErrorNullNotAllowed,Microsoft.PowerShell.Commands.S
   plitPathCommand

Invoke-WebRequest : Cannot validate argument on parameter 'Uri'. The argument is null or empty. Provide an
argument that is not null or empty, and then try the command again.
At C:\Users\Raffaele\Desktop\Nuova cartella\a.ps1:4 char:48
+ $urls | ForEach-Object {Invoke-WebRequest -Uri $_ -OutFile ($_ | Spli ...
+                                                ~~
    + CategoryInfo          : InvalidData: (:) [Invoke-WebRequest], ParameterBindingValidationException
    + FullyQualifiedErrorId : ParameterArgumentValidationError,Microsoft.PowerShell.Commands.InvokeWebReques
   tCommand

我怎样才能克服这个问题？为什么需要internet explorer引擎

---

编辑：我试图以以下方式修改代码：

$site = "https://www.pi.infn.it/~rizzo/ingegneria/appunti_fisII_ing_mecc/"
$psPage = Invoke-WebRequest -Uri $site -UseBasicParsing
$urls = $psPage.ParsedHtml.getElementsByTagName("A")
$urls |  where {$_.pathname -like "*pdf"} | % {Invoke-WebRequest -Uri "$site$($_.pathname)" -OutFile $_.pathname }

错误是：

You cannot call a method on a null-valued expression.
At C:\Users\Raffaele\Desktop\Nuova cartella\a.ps1:3 char:1
+ $urls = $psPage.ParsedHtml.getElementsByTagName("A")
+ ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
    + CategoryInfo          : InvalidOperation: (:) [], RuntimeException
    + FullyQualifiedErrorId : InvokeMethodOnNull

---

编辑2我试图以这种方式修改代码。新代码：

$psPage = Invoke-WebRequest -Uri -UseBasicParsing "https://www.pi.infn.it/~rizzo/ingegneria/appunti_fisII_ing_mecc/"
$urls = $psPage.ParsedHtml.getElementsByTagName("A") | ? {$_.href -like "*.pdf"} | Select-Object -ExpandProperty href
$urls | ForEach-Object {Invoke-WebRequest -Uri $_ -OutFile ($_ | Split-Path -Leaf)}

Windows PowerShell给了我一个新错误：

Invoke-WebRequest : Missing an argument for parameter 'Uri'. Specify a parameter of type 'System.Uri' and
try again.
At C:\Users\Raffaele\Desktop\Nuova cartella\b.ps1:1 char:29
+ $psPage = Invoke-WebRequest -Uri -UseBasicParsing "https://www.pi.inf ...
+                             ~~~~
    + CategoryInfo          : InvalidArgument: (:) [Invoke-WebRequest], ParameterBindingException
    + FullyQualifiedErrorId : MissingArgument,Microsoft.PowerShell.Commands.InvokeWebRequestCommand

You cannot call a method on a null-valued expression.
At C:\Users\Raffaele\Desktop\Nuova cartella\b.ps1:2 char:1
+ $urls = $psPage.ParsedHtml.getElementsByTagName("A") | ? {$_.href -li ...
+ ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
    + CategoryInfo          : InvalidOperation: (:) [], RuntimeException
    + FullyQualifiedErrorId : InvokeMethodOnNull

Split-Path : Cannot bind argument to parameter 'Path' because it is null.
At C:\Users\Raffaele\Desktop\Nuova cartella\b.ps1:3 char:66
+ ... h-Object {Invoke-WebRequest -Uri $_ -OutFile ($_ | Split-Path -Leaf)}
+                                                        ~~~~~~~~~~~~~~~~
    + CategoryInfo          : InvalidData: (:) [Split-Path], ParameterBindingValidationException
    + FullyQualifiedErrorId : ParameterArgumentValidationErrorNullNotAllowed,Microsoft.PowerShell.Commands.S
   plitPathCommand

Invoke-WebRequest : Cannot validate argument on parameter 'Uri'. The argument is null or empty. Provide an
argument that is not null or empty, and then try the command again.
At C:\Users\Raffaele\Desktop\Nuova cartella\b.ps1:3 char:48
+ $urls | ForEach-Object {Invoke-WebRequest -Uri $_ -OutFile ($_ | Spli ...
+                                                ~~
    + CategoryInfo          : InvalidData: (:) [Invoke-WebRequest], ParameterBindingValidationException
    + FullyQualifiedErrorId : ParameterArgumentValidationError,Microsoft.PowerShell.Commands.InvokeWebReques
   tCommand

---

以您的方式：首先，您必须删除URL中的“关于：”或将其替换为零：

$site = "https://www.pi.infn.it/~rizzo/ingegneria/appunti_fisII_ing_mecc/"
$psPage = Invoke-WebRequest $site
$urls = $psPage.ParsedHtml.getElementsByTagName("A") | ? {$_.href -like "*.pdf"} | Select-Object -ExpandProperty href | ForEach-Object {$_.replace("about:", "")}

其次，您必须重新创建完整的URL：

$urls | ForEach-Object {Invoke-WebRequest -Uri "$site$_" -OutFile $_ }

但是您可以使用

“textcontent”

或

“pathname”

简化：

---

这回答了你的问题吗？答案在错误消息中：要么完成IE的首次启动，要么使用-UseBasicPassing参数。嗨@DougMaurer，我添加了-UseBasicPassing，但我仍然有错误（幸运的是另一种错误）。我建议您阅读错误消息，您收到的新错误消息是清楚的（提示：您确实使用了-UseBasicPassing，但之后您忘记了它与url之间的空格）@bluf谢谢您的建议。我编辑了代码并编写了“新的”错误。你好@JPBlanc，请查看编辑。你试过我的吗？你的URI不完整。你好@JPBlanc，在第一次编辑中，我报告了你的代码和相应的错误。奇怪的是，它对我有效。用URL硬编码再试一次？最后一次在全新的shell中肯定有效。可能是隐藏字符有问题？@GennaroArguzzi，复制pa这是最后4行。

$site = "https://www.pi.infn.it/~rizzo/ingegneria/appunti_fisII_ing_mecc/"
$psPage = Invoke-WebRequest $site
$urls = $psPage.ParsedHtml.getElementsByTagName("A")
$urls |  where {$_.pathname -like "*pdf"} | % {Invoke-WebRequest -Uri "$site$($_.pathname)" -OutFile $_.pathname }