powershell - 由于 Internet Explorer 引擎不可用，无法解析响应内容，或者

Question

我需要使用 powershell 下载 channel 9 系列，但是我尝试的脚本有错误:

1. 这个脚本

   $url="https://channel9.msdn.com/blogs/OfficeDevPnP/feed/mp4high"
   $rss=invoke-webrequest -uri $url 
   $destination="D:\Videos\OfficePnP"
   [xml]$rss.Content|foreach{ 
     $_.SelectNodes("rss/channel/item/enclosure") 
   }|foreach{ 
       "Checking $($_.url.split("/")[-1]), we will skip it if it already exists in $($destination)"
     if(!(test-path ($destination + $_.url.split("/")[-1]))){ 
       "Downloading: " + $_.url 
       start-bitstransfer $_.url $destination 
     } 
   }
   

   失败并出现错误:

   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.

2. 我也尝试过这个

   # --- settings ---
   $feedUrl = "https://channel9.msdn.com/blogs/OfficeDevPnP/feed/mp4high"
   $mediaType = "mp4high"
   $overwrite = $false
   $destinationDirectory = join-path ([Environment]::GetFolderPath("MyDocuments")) "OfficeDevPnP"
   
   # --- locals ---
   $webClient = New-Object System.Net.WebClient
   
   # --- functions ---
   function PromptForInput ($prompt, $default) {
    $selection = read-host "$prompt`r`n(default: $default)"
    if ($selection) {$selection} else {$default}
   }
   
   function DownloadEntries {
    param ([string]$feedUrl) 
    $feed = [xml]$webClient.DownloadString($feedUrl)
   
    $progress = 0
    $pagepercent = 0
    $entries = $feed.rss.channel.item.Length
    $invalidChars = [System.IO.Path]::GetInvalidFileNameChars()
    $feed.rss.channel.item | foreach {
       $url = New-Object System.Uri($_.enclosure.url)
       $name = $_.title
       $extension = [System.IO.Path]::GetExtension($url.Segments[-1])
       $fileName = $name + $extension
   
       $invalidchars | foreach { $filename = $filename.Replace($_, ' ') }
       $saveFileName = join-path $destinationDirectory $fileName
       $tempFilename = $saveFilename + ".tmp"
       $filename
       if ((-not $overwrite) -and (Test-Path -path $saveFileName)) 
       {
           write-progress -activity "$fileName already downloaded" -status "$pagepercent% ($progress / $entries) complete" -percentcomplete $pagepercent
       }
       else 
       {
           write-progress -activity "Downloading $fileName" -status "$pagepercent% ($progress / $entries) complete" -percentcomplete $pagepercent
          $webClient.DownloadFile($url, $tempFilename)
          rename-item $tempFilename $saveFileName
       }
       $pagepercent = [Math]::floor((++$progress)/$entries*100)
     }
   }  
   
   # --- do the actual work ---
   [string]$feedUrl = PromptForInput "Enter feed URL" $feedUrl
   [string]$mediaType = PromptForInput "Enter media type`r`n(options:Wmv,WmvHigh,mp4,mp4high,zune,mp3)" $mediaType
   $feedUrl += $mediaType
   
   [string]$destinationDirectory = PromptForInput "Enter destination directory" $destinationDirectory
   
   # if dest dir doesn't exist, create it
   if (!(Test-Path -path $destinationDirectory)) { New-Item $destinationDirectory -type directory }
   
   DownloadEntries $feedUrl
   

   错误太多

   http://screencast.com/t/bgGd0s98Uc

Answer 1

在您的调用 Web 请求中，只需使用参数 -UseBasicParsing

例如在你的脚本(第2行)中你应该使用:

$rss = Invoke-WebRequest -Uri $url -UseBasicParsing

根据the documentation ，在未安装或配置 IE 的系统上此参数是必需的:

Uses the response object for HTML content without Document Object Model (DOM) parsing. This parameter is required when Internet Explorer is not installed on the computers, such as on a Server Core installation of a Windows Server operating system.