如果RSS Updated标头的更新与当前运行的日期相匹配，则检查RSS提要的<updated> </updated>，然后继续下载。
示例RSS提要：
<?xml version="1.0" encoding="UTF-8" ?>
<feed xmlns="http://www.w3.org/2005/Atom">
<title type="text"> Updates</title>
<subtitle type="html"><![CDATA[Latest updates]]></subtitle>
<link href="http://website/website.rss"></link>
<id>http://website</id>
<link rel="alternate" type="text/html" href="http://website/website.rss" ></link>
<link rel="self" type="application/atom+xml" href="https://website/site/download" ></link>
<logo>http://website/website</logo>
<updated>2020-03-28 T17:32:48+00:00</updated>
<entry>
<author>
<name>ueam</name>
</author>
<title type="text"><![CDATA[2.0.4516]]></title>
<link rel="alternate" type="text/html" href="https://website/site/download"></link>
<id>https://website/site/download</id>
<summary type="html"><![CDATA[<ul>
<li>Patched for March 23rd update</li>
<li>Fixed known bug JIRA</li>
</ul>]]></summary>
<content type="html"><![CDATA[]]></content>
<updated>2020-03-28 17:32:48</updated>
</entry>
<entry>
<author>
<name>Team</name>
</author>
<title type="text"><![CDATA[2.0.4516]]></title>
<link rel="alternate" type="text/html" href="https://website/site/download"></link>
<id>https://website/site/download</id>
<summary type="html"><![CDATA[<ul>
<li>
Patch for March 23rd update
</li>
</ul>]]></summary>
<content type="html"><![CDATA[]]></content>
<updated>2020-03-28 17:32:48</updated>
</entry>
<entry>
<author>
<name>Team</name>
</author>
<title type="text"><![CDATA[2.0.4514]]></title>
<link rel="alternate" type="text/html" href="https://website/site/download></link>
<id>https://website/site/download</id>
<summary type="html"><![CDATA[<ul>
<li>Fixed Bug</li>
此处
<updated>2020-03-28 17:32:48</updated>
显示了如果我今天运行，那么将继续下载，因为它与当天的匹配
下载将通过调用
Invoke-WebRequest -uri https://website/site/download
我只是不知道如何解析RSS以查看"更新的"并与当前日期进行比较，如果日期匹配，则继续下载。
更新：我尝试了以下
#Grab RSS
$rssString = Invoke-WebRequest "http://website/website.rss"
# convert rss to xml
$xml = [xml] $rssString
# select the <updated> node
$updateString = $xml.SelectSingleNode("/feed/updated").innerText
# convert string to date
$date = Get-Date $updateString
# compare to todays date
if($date.Date -eq (Get-Date).Date){
# proceed to download
}
您收到以下错误：Get-Date:无法将参数"Date"绑定到目标。设置"日期"时出现异常："无法将null转换为类型"System.DateTime"。">
当你运行
$updatestring
没有返回任何内容并且为空，似乎更新的节点没有被读取
RSS是xml，所以这样对待它：(
根<feed>下的<updated>节点似乎反映了最新的更新，因此请注意：
# convert rss to xml
$xml = [xml]$rssString;
# select the <updated> node
$updateString = $xml.SelectSingleNode("/feed/updated").innerText
# convert string to date
$date = Get-Date $updateString
# compare to todays date
if($date.Date -eq (Get-Date).Date){
# proceed to download
}