在NuGet初始化脚本不工作时保存XML文档

Question

我正在尝试编写一个NuGet程序包init.ps1脚本，它将修改.targets文件（XML）的一个值并保存文档。脚本没有错误地成功完成所有事情，但是当我检查文档时，它并没有被更改。

下面是脚本：

Param($installPath, $toolsPath, $package) 

$proj = Get-Project 
$pack = $package 

# Detect if the project installing the NuGet package is a web application and 
# alters an xml element value in the .targets value to prevent duplication 
# of application resources when published. 

if ($proj.ExtenderNames -contains "WebApplication") { 
    # Begin to build neccessary path strings to find the .targets file. 
    # The targets file is currently located in 
    # \packages\packageName.packageVersion\build\packageName.targets. 
    $packageName = [string]$pack.Id 

    $packageRootDir = $installPath 

    # packageName.Version\build 
    $packageBuildFolderPath = Join-Path $packageRootDir "build" 

    # packageName.Version\build\packageName 
    $targetsFilePath = Join-Path $packageBuildFolderPath ($packageName + ".targets") 
    "$targetsFilePath" 

    if (Test-Path $targetsFilePath) { 
     # If the targets file path has correctly located the file then 
     # we edit the targets file to alter the CopyToOutputDirectory element. 

     # Load the targets file as an xml object 
     $xml = New-Object System.Xml.XmlDocument 
     $xml.Load($targetsFilePath) 
     "xml loaded" 
     # Search each ItemGroup element for the one containing a Content element. 
     foreach ($group in $xml.Project.ItemGroup) { 
      $nodeExists = $group.Content.CopyToOutputDirectory 

      if ($nodeExists) { 
       "$nodeExists" 
       # Edits the value when we find the correct node 
       $nodeExists = "Never" 
       "$nodeExists" 
      } 
     } 
     "xml modified" 

     # Save the updated document to the correct place. 
     $savePath = [string]$targetsFilePath 
     "$savePath" 
     $xml.Save($savePath) 
     "xml Saved to $savePath" 
    } 
} 

，这里是从一开始就包管理器输出，结束脚本块：

 
Executing script file 'path to tools/Init.ps1' 
'correct path to package/build/package.targets' 
xml loaded 
Always 
Never 
xml modified 
'correct path to package/build/package.targets' 
xml Saved to 'correct path to package/build/package.targets' 

Answer 1

你的代码修改变量$nodeExists的价值，但不包括值来自的XML节点。您可以验证通过在循环后考虑看看实际的XML数据：

$xml.Save([Console]::Out) 

实际修改节点的值更改您的代码是这样的：

foreach ($group in $xml.Project.ItemGroup) { 
    if ($group.Content.CopyToOutputDirectory) { 
     $group.Content.CopyToOutputDirectory = 'Never' 
    } 
} 

或类似这样的：

$xml.SelectNodes('//Content/CopyToOutputDirectory') | ForEach-Object { 
    $_.'#text' = 'Never' 
} 

注意，后者需要namespace manager，如果你的XML使用命名空间。