如何用PowerShell筛选XML中Dilbert节点下TTT的Default和CurrentValue

尝试读取XML文档，仅获取Dilbert节点下TTT子节点的Default和CurrentValue的名称与对应值，但当前PowerShell代码输出了Dilbert节点下所有子节点的相关值，无法缩小范围。

当前代码 #

[xml]$doc = Get-Content  c:\Temp\TTTOrderSettings.xml

foreach($key in $doc.Configuration.Key)
#foreach($key in $doc.Configuration.Key.Key)
{
  if( ($key.Name -eq "Dilbert") )
  {
    if($key.Key.Name -eq "TTT")
    {
      #Key = $key.Name
      #Value = $key.Value
      echo $key.Key.Name
      echo $key.Key.Value
      #echo $key.Key.Name.Default
    }
  }

当前输出 #

Selection
TTT
Front
Preview
Priority
Finish
RedFaced

Name         #text       
----         -----       
Default      SelectManual
CurrentValue SelectManual
Default      Enhanced    
CurrentValue Enhanced    
Default      False       
CurrentValue False       
Default      True        
CurrentValue True        
Default      PriorityASAP
CurrentValue PriorityASAP
Default      Fabulous    
CurrentValue Fabulous    
Default      false       
CurrentValue False 

XML文件内容 #

<?xml version="1.0" encoding="utf-16"?>
<Configuration>
    <Key Name="Archive">
        <Key Name="Selection">
            <Value Name="Default">SelectAll</Value>
            <Value Name="CurrentValue">SelectAll</Value>
        </Key>
        <Key Name="Front">
            <Value Name="Default">False</Value>
            <Value Name="CurrentValue">False</Value>
        </Key>
        <Key Name="Preview">
            <Value Name="Default">True</Value>
            <Value Name="CurrentValue">True</Value>
        </Key>
        <Key Name="Priority">
            <Value Name="Default">PriorityASAP</Value>
            <Value Name="CurrentValue">PriorityASAP</Value>
        </Key>
        <Key Name="Finish">
            <Value Name="Default">Fabulous</Value>
            <Value Name="CurrentValue">Fabulous</Value>
        </Key>
        <Key Name="RedFaced">
            <Value Name="Default">false</Value>
            <Value Name="CurrentValue">false</Value>
        </Key>
    </Key>
    <Key Name="Batch">
        <Key Name="TTT">
            <Value Name="Default">Off</Value>
            <Value Name="CurrentValue">Off</Value>
        </Key>
        <Key Name="Front">
            <Value Name="Default">False</Value>
            <Value Name="CurrentValue">False</Value>
        </Key>
        <Key Name="Preview">
            <Value Name="Default">True</Value>
            <Value Name="CurrentValue">True</Value>
        </Key>
        <Key Name="Priority">
            <Value Name="Default">PriorityASAP</Value>
            <Value Name="CurrentValue">PriorityASAP</Value>
        </Key>
        <Key Name="Finish">
            <Value Name="Default">Fabulous</Value>
            <Value Name="CurrentValue">Fabulous</Value>
        </Key>
        <Key Name="RedFaced">
            <Value Name="Default">false</Value>
            <Value Name="CurrentValue">false</Value>
        </Key>
        <Key Name="Scan">
            <Value Name="Default">Medium</Value>
            <Value Name="CurrentValue">Medium</Value>
        </Key>
        <Key Name="Type">
            <Value Name="Default">bed</Value>
            <Value Name="CurrentValue">bed</Value>
        </Key>
    </Key>
    <Key Name="Dilbert">
        <Key Name="Selection">
            <Value Name="Default">SelectManual</Value>
            <Value Name="CurrentValue">SelectManual</Value>
        </Key>
        <Key Name="TTT">
            <Value Name="Default">Enhanced</Value>
            <Value Name="CurrentValue">Enhanced</Value>
        </Key>
        <Key Name="Front">
            <Value Name="Default">False</Value>
            <Value Name="CurrentValue">False</Value>
        </Key>
        <Key Name="Preview">
            <Value Name="Default">True</Value>
            <Value Name="CurrentValue">True</Value>
        </Key>
        <Key Name="Priority">
            <Value Name="Default">PriorityASAP</Value>
            <Value Name="CurrentValue">PriorityASAP</Value>
        </Key>
        <Key Name="Finish">
            <Value Name="Default">Fabulous</Value>
            <Value Name="CurrentValue">Fabulous</Value>
        </Key>
        <Key Name="RedFaced">
            <Value Name="Default">false</Value>
            <Value Name="CurrentValue">False</Value>
        </Key>
    </Key>
    <Key Name="Flimsy">
        <Key Name="Softy">
            <Value Name="Default">true</Value>
            <Value Name="CurrentValue">True</Value>
        </Key>
        <Key Name="OrderType">
            <Value Name="Default">OrderTypeNew</Value>
            <Value Name="CurrentValue">OrderTypeNew</Value>
        </Key>
        <Key Name="Resolution">
            <Value Name="Default">Medium</Value>
            <Value Name="CurrentValue">Medium</Value>
        </Key>
        <Key Name="Boastable">
            <Value Name="Default">false</Value>
            <Value Name="CurrentValue">False</Value>
        </Key>
        <Key Name="Type">
            <Value Name="Default">Full</Value>
            <Value Name="CurrentValue">Full</Value>
        </Key>
        <Key Name="TTT">
            <Value Name="Default">Enhanced</Value>
            <Value Name="CurrentValue">Enhanced</Value>
        </Key>
        <Key Name="Front">
            <Value Name="Default">False</Value>
            <Value Name="CurrentValue">False</Value>
        </Key>
        <Key Name="Preview">
            <Value Name="Default">True</Value>
            <Value Name="CurrentValue">True</Value>
        </Key>
        <Key Name="Priority">
            <Value Name="Default">PriorityASAP</Value>
            <Value Name="CurrentValue">PriorityASAP</Value>
        </Key>
        <Key Name="Finish">
            <Value Name="Default">Fabulous</Value>
            <Value Name="CurrentValue">Fabulous</Value>
        </Key>
        <Key Name="RedFaced">
            <Value Name="Default">false</Value>
            <Value Name="CurrentValue">false</Value>
        </Key>
        <Key Name="Included">
            <Value Name="Default">true</Value>
            <Value Name="CurrentValue">true</Value>
        </Key>
    </Key>

</Configuration>

可以通过两种方式精准定位目标节点：

方法一：使用XPath直接查询 #

XPath是XML文档查询的高效方式，能直接定位到Dilbert下的TTT节点，再提取其Value子节点：

[xml]$doc = Get-Content c:\Temp\TTTOrderSettings.xml
# 用XPath定位目标节点
$tttNode = $doc.SelectSingleNode("//Key[@Name='Dilbert']/Key[@Name='TTT']")
# 输出Default和CurrentValue
$tttNode.Value

方法二：优化循环逻辑 #

原代码的问题在于，当$key.Name -eq "Dilbert"时，$key.Key是Dilbert下的所有子Key节点集合，直接判断$key.Key.Name -eq "TTT"不符合预期，需要遍历该集合：

[xml]$doc = Get-Content c:\Temp\TTTOrderSettings.xml

foreach($parentKey in $doc.Configuration.Key)
{
    if($parentKey.Name -eq "Dilbert")
    {
        # 遍历Dilbert下的所有子Key节点
        foreach($childKey in $parentKey.Key)
        {
            if($childKey.Name -eq "TTT")
            {
                # 输出TTT节点下的Value
                $childKey.Value
                break # 找到目标后退出循环，提升效率
            }
        }
    }
}

预期输出 #

两种方法都会得到如下结果：

Name         #text       
----         -----       
Default      Enhanced    
CurrentValue Enhanced    

内容的提问来源于stack exchange，提问作者Michele