powershell 操作XML

$file = "C:\Users\HHH\Desktop\ddd\Web.config"
$xml = New-Object -TypeName xml
$xml.Load($file)
function XmlAdd
{
    Param (
        $xml,
        $Pattern,
        $Content,
        $After = $null
    )
    $Content=$Content.Trim()
    $Content=[xml]$Content
    $pnode=Select-Xml -Xml $xml -XPath $Pattern
    if ($After -ne $null) {
        $After = [xml]$After
        $Location = $pnode.Node.InnerXml.IndexOf($After.OuterXml)
    }
    if ($pnode -ne $null) {
        if (-not ($pnode.Node.InnerXml.Contains($Content.OuterXml))) {
            if ($After -eq $null -or $Location -eq -1) {
                $pnode.Node.InnerXml+=$Content.OuterXml
            }else {
                $InsertLocation = $Location+$After.OuterXml.Length
                $AddString = $pnode.Node.InnerXml.Substring(0,$InsertLocation)+$Content.OuterXml+$pnode.Node.InnerXml.Substring($InsertLocation)
                $pnode.Node.InnerXml=$addstring
            }
        }
    }
}
$xpath = '//appSettings/add[@key="CompanyCode"]'
if (Select-Xml -Xml $xml -XPath $xpath){
    $item = Select-Xml -Xml $xml -XPath $xpath
    $item.Node.Value = "test"
    $xml.Save($file)
}
else {    
    $Content='<add key="CompanyCode" value="nnono" />'
    $Pattern="/configuration/appSettings"
    XmlAdd $xml $Pattern $Content
    $xml.Save($file)  
}
# 研究xml管理整理
# 函数
# outerxml    获取包含此节点及其所有子节点的标记
# innerxml    获取或设置仅表示此节点的子节点的标记
# substring   用于提取字符串中介于两个指定下标之间的字符 
# contains    用于判断字符串中是否包含指定的字符或字符串
# Xpath常用语法总结
## https://www.cnblogs.com/ruhai/p/10705719.html
# 命令
# Select-Xml
# select-object
# new-object

参考:https://blog.vichamp.com/2017/06/03/Mastering-Everyday-XML-Tasks-in-PowerShell/
https://www.cnblogs.com/Ulysse/p/14939143.html#/c/subject/p/14939143.html