如何在C#中移除XML里名称全大写的属性（含示例）

Here's how you can strip out all attributes with fully uppercase names (like AIRPORTNAME in your sample XML) using C#. I'll cover two practical approaches—one with the modern LINQ to XML API, and another with the traditional XmlDocument for older projects.

Using LINQ to XML (Recommended) #

This method is straightforward and leverages LINQ for clean, readable code:

using System;
using System.Linq;
using System.Xml.Linq;

class Program
{
    static void Main()
    {
        // Your raw XML content
        string xmlContent = @"<Flight flightOriginDate=""2018-08-20"" scheduledTimeOfDeparture=""2018-08-20T16:15:00""> 
<FlightIdentification> 
<FLIGHTIDENTIFIGHER> ATS-FPL </FLIGHTIDENTIFIGHER> CLEAR 
<FlightNumber airlineIATACode=""two letter code"" number=""275"" operationalSuffix=""A""> 
<CommercialFlightNumber>275A</CommercialFlightNumber> --""concatnation of IATA Code, Number and operational Suffix"" 
</FlightNumber> 
</FlightIdentification> 
<DepartureAirport AIRPORTNAME=""PORTLAND INTL"" airportFunction=""Departure Airport"" -- HC MASTER > 
<AirportICAOCode>KPWM</AirportICAOCode> 
<AirportIATACode>PWM</AirportIATACode> 
</DepartureAirport> 
<ArrivalAirport airportName=""HEATHROW"" airportFunction="" Arrival Airport"" > 
<AirportICAOCode>EGLL</AirportICAOCode> 
<AirportIATACode>LHR</AirportIATACode> 
</ArrivalAirport> 
</Flight>";

        // Load XML into an XDocument
        XDocument doc = XDocument.Parse(xmlContent);

        // Find all attributes where the name is fully uppercase, then remove them
        doc.Descendants()
           .Attributes()
           .Where(attr => attr.Name.LocalName.All(char.IsUpper))
           .Remove();

        // Output the modified XML
        Console.WriteLine(doc.ToString());
    }
}

How this works: #

• XDocument.Parse() loads your XML string into an in-memory document.
• Descendants() grabs every element in the XML tree, and Attributes() pulls all attributes from those elements.
• The Where clause filters attributes whose local name (ignoring any namespace prefixes) consists entirely of uppercase letters.
• Remove() deletes all matching attributes in one go.

Using XmlDocument (Legacy Approach) #

If you're working with an older codebase that uses XmlDocument, this method will get the job done:

using System;
using System.Xml;
using System.Linq;

class Program
{
    static void Main()
    {
        string xmlContent = @"<Flight flightOriginDate=""2018-08-20"" scheduledTimeOfDeparture=""2018-08-20T16:15:00""> 
<FlightIdentification> 
<FLIGHTIDENTIFIGHER> ATS-FPL </FLIGHTIDENTIFIGHER> CLEAR 
<FlightNumber airlineIATACode=""two letter code"" number=""275"" operationalSuffix=""A""> 
<CommercialFlightNumber>275A</CommercialFlightNumber> --""concatnation of IATA Code, Number and operational Suffix"" 
</FlightNumber> 
</FlightIdentification> 
<DepartureAirport AIRPORTNAME=""PORTLAND INTL"" airportFunction=""Departure Airport"" -- HC MASTER > 
<AirportICAOCode>KPWM</AirportICAOCode> 
<AirportIATACode>PWM</AirportIATACode> 
</DepartureAirport> 
<ArrivalAirport airportName=""HEATHROW"" airportFunction="" Arrival Airport"" > 
<AirportICAOCode>EGLL</AirportICAOCode> 
<AirportIATACode>LHR</AirportIATACode> 
</ArrivalAirport> 
</Flight>";

        XmlDocument doc = new XmlDocument();
        doc.LoadXml(xmlContent);

        // Get all elements in the XML
        XmlNodeList allNodes = doc.SelectNodes("//*");
        foreach (XmlNode node in allNodes)
        {
            if (node.Attributes != null)
            {
                // Collect attributes to remove first (can't modify collection while iterating)
                var attributesToRemove = node.Attributes.Cast<XmlAttribute>()
                    .Where(attr => attr.Name.All(char.IsUpper))
                    .ToList();

                // Remove each matching attribute
                foreach (XmlAttribute attr in attributesToRemove)
                {
                    node.Attributes.Remove(attr);
                }
            }
        }

        // Output the updated XML
        Console.WriteLine(doc.OuterXml);
    }
}

Key notes for this method: #

• We first collect all attributes to remove into a list because you can't modify the XmlAttributeCollection while iterating over it (it causes an enumeration error).
• SelectNodes("//*") selects every element in the XML document, ensuring we don't miss any attributes.

Customizing the Filter #

If you need to adjust the logic (e.g., remove attributes where all letters are uppercase, even if there are non-letter characters like numbers or underscores), modify the filter condition to:

attr.Name.LocalName.Where(char.IsLetter).All(char.IsUpper)

This will ignore non-letter characters when checking if the name is "effectively" uppercase.

内容的提问来源于stack exchange，提问作者Mallik Naidu