即使两个字符串相同，使用 ！= 的字符串比较也会返回 true

问：

我的 asp.net 应用程序中有以下代码：

if (i["ProjectDescription"] != null && properties.ItemEventProperties.AfterProperties["ProjectDescription"] != null && (Regex.Replace(i["ProjectDescription"].ToString(), "<.*?>", String.Empty) != Regex.Replace(properties.ItemEventProperties.AfterProperties["ProjectDescription"].ToString(), "<.*?>", String.Empty)))
 {
    var g = Regex.Replace(i["ProjectDescription"].ToString(), "<.*?>", String.Empty);
    var gg = Regex.Replace(properties.ItemEventProperties.AfterProperties["ProjectDescription"].ToString(), "<.*?>", String.Empty);
}

现在properties.ItemEventProperties.AfterProperties["ProjectDescription"] =

<div class=\"ExternalClassB4424BCE886A43C980835358CB67D0E8\"><p>This project will be to update Win Server 2008 or older server OS to Win Server 2016.q​123​​<br><br></p><p>It will exclude Win Server 2012.&#160;</p><p>Check attached spreadsheet in draft for list of servers and check the POF&#160;</p><p>Licenses&#58;</p><p>Tere will&#160; be a total of 9 Server VMs upgraded on-premises that require Win Server Licenses.&#160;<br></p><p>There are also 2 existing VMs running on Win Server 2012.<br></p><p>This will require&#160;​6 x (16 cores licenses x 3 hosts) ---&gt; Total 18 x 16 cores Win Standard License​<br>already have 5 x 16 cores Win Standard licenses</p><p>We will need to quote and order for additional 13​ x&#160; Win Server Standard16 cores licenses​<br></p><p>The VM's running on Cloud will be licensed through monthly hosting costs</p><p><strong>Cost Summary&#58;​</strong><br>Licenses - £12,612.60<br>Engineer Resources - £7,880.00<br></p></div>

这i["ProjectDescription"]=

<div class=\"ExternalClassB4424BCE886A43C980835358CB67D0E8\"><p>This project will be to update Win Server 2008 or older server OS to Win Server 2016.q​123<br><br></p><p>It will exclude Win Server 2012.&#160;</p><p>Check attached spreadsheet in draft for list of servers and check the POF&#160;</p><p>Licenses&#58;</p><p>Tere will&#160; be a total of 9 Server VMs upgraded on-premises that require Win Server Licenses.&#160;<br></p><p>There are also 2 existing VMs running on Win Server 2012.<br></p><p>This will require&#160;​6 x (16 cores licenses x 3 hosts) ---&gt; Total 18 x 16 cores Win Standard License​<br>already have 5 x 16 cores Win Standard licenses</p><p>We will need to quote and order for additional 13​ x&#160; Win Server Standard16 cores licenses​<br></p><p>The VM's running on Cloud will be licensed through monthly hosting costs</p><p><strong>Cost Summary&#58;​</strong><br>Licenses - £12,612.60<br>Engineer Resources - £7,880.00<br></p></div>

此外，结果将重新运行以下内容：-Regex

This project will be to update Win Server 2008 or older server OS to Win Server 2016.q​123It will exclude Win Server 2012. Check attached spreadsheet in draft for list of servers and check the POF Licenses:Tere will  be a total of 9 Server VMs upgraded on-premises that require Win Server Licenses. There are also 2 existing VMs running on Win Server 2012.This will require ​6 x (16 cores licenses x 3 hosts) ---> Total 18 x 16 cores Win Standard License​ already have 5 x 16 cores Win Standard licensesWe will need to quote and order for additional 13​ x  Win Server Standard16 cores licenses​The VM's running on Cloud will be licensed through monthly hosting costsCost Summary:​Licenses - £12,612.60Engineer Resources - £7,880.00

但是上面的字符串比较将返回 true，尽管 2 个字符串是相同的。那么谁能建议呢？