我在 Microsoft 网站上发现了一个关于 Windows 更新的示例 vbscript 程序（名为 WUA_SearchDownloadInstall.vbs）。
http://msdn.microsoft.com/en-us/library/aa387102%28VS.85%29.aspx
Set updateSession = CreateObject("Microsoft.Update.Session")
Set updateSearcher = updateSession.CreateupdateSearcher()
WScript.Echo "Searching for updates..." & vbCRLF
Set searchResult = _
updateSearcher.Search("IsInstalled=0 and Type='Software'")
WScript.Echo "List of applicable items on the machine:"
For I = 0 To searchResult.Updates.Count-1
Set update = searchResult.Updates.Item(I)
WScript.Echo I + 1 & "> " & update.Title
Next
If searchResult.Updates.Count = 0 Then
WScript.Echo "There are no applicable updates."
WScript.Quit
End If
WScript.Echo vbCRLF & "Creating collection of updates to download:"
Set updatesToDownload = CreateObject("Microsoft.Update.UpdateColl")
For I = 0 to searchResult.Updates.Count-1
Set update = searchResult.Updates.Item(I)
WScript.Echo I + 1 & "> adding: " & update.Title
updatesToDownload.Add(update)
Next
WScript.Echo vbCRLF & "Downloading updates..."
Set downloader = updateSession.CreateUpdateDownloader()
downloader.Updates = updatesToDownload
downloader.Download()
WScript.Echo vbCRLF & "List of downloaded updates:"
For I = 0 To searchResult.Updates.Count-1
Set update = searchResult.Updates.Item(I)
If update.IsDownloaded Then
WScript.Echo I + 1 & "> " & update.Title
End If
Next
Set updatesToInstall = CreateObject("Microsoft.Update.UpdateColl")
WScript.Echo vbCRLF & _
"Creating collection of downloaded updates to install:"
For I = 0 To searchResult.Updates.Count-1
set update = searchResult.Updates.Item(I)
If update.IsDownloaded = true Then
WScript.Echo I + 1 & "> adding: " & update.Title
updatesToInstall.Add(update)
End If
Next
WScript.Echo vbCRLF & "Would you like to install updates now? (Y/N)"
strInput = WScript.StdIn.Readline
WScript.Echo
If (strInput = "N" or strInput = "n") Then
WScript.Quit
ElseIf (strInput = "Y" or strInput = "y") Then
WScript.Echo "Installing updates..."
Set installer = updateSession.CreateUpdateInstaller()
installer.Updates = updatesToInstall
Set installationResult = installer.Install()
'Output results of install
WScript.Echo "Installation Result: " & _
installationResult.ResultCode
WScript.Echo "Reboot Required: " & _
installationResult.RebootRequired & vbCRLF
WScript.Echo "Listing of updates installed " & _
"and individual installation results:"
For I = 0 to updatesToInstall.Count - 1
WScript.Echo I + 1 & "> " & _
updatesToInstall.Item(i).Title & _
": " & installationResult.GetUpdateResult(i).ResultCode
Next
End If
他的脚本运行良好，直到它到达
downloader.Download()
在该行上，CMD 窗口输出
C:\wu-install\WUA_SearchDownloadInstall.vbs(37, 1) (null): 0x80240044
通过在前面添加 printf 行downloader.Download()，我可以看到错误在 Download() 中立即断言。
我的问题是：我怎样才能找到知道错误原因的线索？可能有办法捕获异常并让输出一些详细的错误消息。
我在这篇文章的帮助下进行了尝试（看起来像一个 VBscript 异常，如何应对？），并围绕问题行写：
On Error Resume Next
downloader.Download()
If Err.Number <> 0 Then
WScript.Echo Err.Description
WScript.Quit 4
End If
On Error Goto 0
但WScript.Echo Err.Description什么也没输出。我能怎么做？
我的环境：Windows 7 32 位。
[[[ 更新 ]]]
这个问题我回来了。我已经更新了我的脚本以使用 JScript。是的，它比 VBScript 方便。
现在我有这样的代码片段：
var downloader = updsession.CreateUpdateDownloader()
downloader.Updates = updatesToDownload
try {
downloader.Download()
}
catch(err) {
WScript.Echo("Oops, Download error.")
WScript.Echo("Possible reason:")
WScript.Echo("* On Windows Vista/7, This requires you Run as Administrator.")
WScript.Quit(3)
}
剩下的问题是：如何从 Download() 获取错误代码，以便检查错误原因。http://msdn.microsoft.com/en-us/library/windows/desktop/aa386134%28v=vs.85%29.aspx上的页面对我来说似乎太粗糙了，无法找到答案。
再次等待您的帮助。谢谢你。