PowerShell - 解析 XML 字符串

Question

I am running a SQL query and one of the fields returned contains a string that is formatted as XML. The string returned is a single line containing all the elements, I added carriage returns for readability. I have tried converting the string to XML using "convertto-xml" and it seems to create an XML object, but I cannot seem to parse it. I readily admit I am a newbie when it comes to dealing with XML, but I cannot seem to be able to parse the objects. I am specifically trying to find the value of the parameter named "TO". I have tried looking for "childnodes" and "innertext" but cannot enumerate the elements. I am not even sure if, after conversion, these are elements or attributes.

Here is the string:

$String = "
<ParameterValues>
    <ParameterValue>
        <Name>TO</Name>
        <Value>Address1@domain.com;address2@domain.com</Value>
    </ParameterValue>
    <ParameterValue>
        <Name>Subject</Name>
        <Value>Emailsubject</Value>
    </ParameterValue>
    <ParameterValue>
        <Name>Comment</Name>
        <Value>ReportComment</Value>
    </ParameterValue>
    <ParameterValue>
        <Name>RenderFormat</Name>
        <Value>MHTML</Value>
    </ParameterValue>
    <ParameterValue>
        <Name>Priority</Name>
        <Value>Normal</Value>
    </ParameterValue>
    <ParameterValue>
        <Name>IncludeLink</Name>
        <Value>true</Value>
    </ParameterValue>
    <ParameterValue>
        <Name>IncludeReport</Name>
        <Value>true</Value>
    </ParameterValue>
</ParameterValues>
"

I used: $Newstring = $string | convertto-xml

to get the XML object. How do I address the parametervalue "TO"? Dot addressing doesn't seem to work

Answer 1

As vonPryz commented, you can use the [xml] type accellerator to read the string as XML.

Then it is quite easy to get the values you seek:

[xml]$xml = $string
$to = ($xml.ParameterValues.ParameterValue | Where-Object { $_.Name -eq 'TO' }).Value -split ';'
$to

Result:

Address1@domain.com
address2@domain.com

Answer 2

Likewise to @Theo's good answer there are a few ways to get at the data, but they are all rooted in the [XML] type accelerator.

$String = "
<ParameterValues>
    <ParameterValue>
        <Name>TO</Name>
        <Value>Address1@domain.com;address2@domain.com</Value>
    </ParameterValue>
    <ParameterValue>
        <Name>Subject</Name>
        <Value>Emailsubject</Value>
    </ParameterValue>
    <ParameterValue>
        <Name>Comment</Name>
        <Value>ReportComment</Value>
    </ParameterValue>
    <ParameterValue>
        <Name>RenderFormat</Name>
        <Value>MHTML</Value>
    </ParameterValue>
    <ParameterValue>
        <Name>Priority</Name>
        <Value>Normal</Value>
    </ParameterValue>
    <ParameterValue>
        <Name>IncludeLink</Name>
        <Value>true</Value>
    </ParameterValue>
    <ParameterValue>
        <Name>IncludeReport</Name>
        <Value>true</Value>
    </ParameterValue>
</ParameterValues>
"

$String = [XML]$String

( $String.ParameterValues.ParameterValue | 
Where-Object{ $_.Name -eq 'TO' } ).Value

A slightly shorter version using the .Where() method:

#...
( $String.ParameterValues.ParameterValue).Where( { $_.Name -eq 'TO' } ).Value

The particular XML structure makes this a bit confusing. Inside each ParameterValue element is essentially a Name/Value pair that in concept looks a lot like a dictionary object. So if you have to go beyond getting just the one value maybe you can actually convert to a dictionary; something like:

$Hash = @{}
$String.ParameterValues.ParameterValue |
ForEach-Object{
    $Hash.Add( $_.Name, $_.Value )
}

$Hash.To
$Hash.Subject
$Hash.Comment
# ...