Question

我有这个XML：

<?xml version="1.0" encoding="utf-8"?>
<JMF SenderID="InkZone-Controller" Version="1.2">
  <Command ID="cmd.00695" Type="Resource">
    <ResourceCmdParams ResourceName="InkZoneProfile" JobID="K_41">
      <InkZoneProfile ID="r0013" Class="Parameter" Locked="false" Status="Available" PartIDKeys="SignatureName SheetName Side Separation" DescriptiveName="Schieberwerte von DI" ZoneWidth="32">
        <InkZoneProfile SignatureName="SIG1">
          <InkZoneProfile Locked="False" SheetName="S1">
            <InkZoneProfile Side="Front">
              <ColorPool Class="Parameter" DescriptiveName="Colors for the job" Status="Available">
                <InkZoneProfile Separation="PANTONE 647 C" ZoneSettingsX="0 0,003 " />
              </ColorPool>
            </InkZoneProfile>
          </InkZoneProfile>
        </InkZoneProfile>
      </InkZoneProfile>
    </ResourceCmdParams>
  </Command>
</JMF>

我尝试使用XElement和Linq在特定节点（）之后添加节点。但我的LINQ查询总是返回null。试过这个：

            XElement InkZonePath = XmlDoc.Element("JMF").Elements("InkZoneProfile").Where(z => z.Element("InkZoneProfile").Attribute("Side").Value == "Front").SingleOrDefault();

而且：

            XmlDoc.Element("JMF")
                   .Elements("InkZoneProfile").Where(InkZoneProfile => InkZoneProfile.Attribute("Side")
                   .Value == "Front").FirstOrDefault().AddAfterSelf(new XElement("InkZoneProfile",
                   new XAttribute("Separation", x.colorname),
                   new XAttribute("ZoneSettingsX", x.colorvalues)));

我按照这些示例构建了这些查询：

Select XElement where child element has a value

Insert XElements after a specific node

LINQ-to-XML XElement query NULL

但它并没有像预期的那样奏效。 LINQ查询有什么问题？从我所读到的它应该起作用（逻辑上阅读我能理解的表达方式）。

由于

EDIT-1：整个writexml方法

public void writexml(xmldatalist XMLList, variables GlobalVars)
        {

            XmlWriterSettings settings = new XmlWriterSettings
            {
                Indent = true,
                IndentChars = "\t",
                NewLineChars = Environment.NewLine,
                NewLineHandling = NewLineHandling.Replace,
                Encoding = new UTF8Encoding(false)
            };

            string DesktopFolder = Environment.GetFolderPath(Environment.SpecialFolder.DesktopDirectory);
            string FileExtension = ".xml";
            string PathString = Path.Combine(DesktopFolder, "XML");
            System.IO.Directory.CreateDirectory(PathString);


            foreach (List<xmldata> i in XMLList.XMLArrayList)
            {
                int m = 0;
                foreach (var x in i)
                {

                    string XMLFilename = System.IO.Path.GetFileNameWithoutExtension(x.xml_filename);                    
                    GlobalVars.FullPath = Path.Combine(PathString, XMLFilename + FileExtension);


                    if (!File.Exists(GlobalVars.FullPath))
                    {
                        XDocument doc = new XDocument(
                         new XDeclaration("1.0", "utf-8", "yes"),

                         new XElement("JMF",
                             new XAttribute("SenderID", "InkZone-Controller"),
                             new XAttribute("Version", "1.2"),
                        new XElement("Command",
                             new XAttribute("ID", "cmd.00695"),
                             new XAttribute("Type", "Resource"),
                        new XElement("ResourceCmdParams",
                            new XAttribute("ResourceName", "InkZoneProfile"),
                            new XAttribute("JobID", "K_41"),
                        new XElement("InkZoneProfile",
                            new XAttribute("ID", "r0013"),
                            new XAttribute("Class", "Parameter"),
                            new XAttribute("Locked", "False"),
                            new XAttribute("Status", "Available"),
                            new XAttribute("PartIDKeys", "SignatureName SheetName Side Separation"),
                            new XAttribute("DescriptiveName", "Schieberwerte von DI"),
                            new XAttribute("ZoneWidth", "32"),
                        new XElement("InkZoneProfile",
                            new XAttribute("SignatureName", "SIG1"),
                        new XElement("InkZoneProfile",
                            new XAttribute("Locked", "false"),
                            new XAttribute("SheetName", "S1"),
                        new XElement("InkZoneProfile",
                            new XAttribute("Side", "Front"),
                        new XElement("ColorPoolClass",
                            new XAttribute("Class", "Parameter"),
                            new XAttribute("DescriptiveName", "Colors for the job"),
                            new XAttribute("Status", "Available")
                            )))))))));
                        doc.Save(GlobalVars.FullPath);

                        XDocument XmlDoc = new XDocument();
                        XmlDoc = XDocument.Load(GlobalVars.FullPath);
                        XElement InkZonePath = XmlDoc.Root.Descendants("InkZoneProfile").Where(z => (string)z.Attribute("Side") == "Front").SingleOrDefault();

                        if (InkZonePath != null)
                        {
                            InkZonePath.AddAfterSelf(new XElement("InkZoneProfile",
                                   new XAttribute("Separation", x.colorname),
                                   new XAttribute("ZoneSettingsX", x.colorvalues)));

                        }
                        XmlDoc.Save(GlobalVars.FullPath);

                        }//Closing !FileExists
                    }//Closing inner foreach


            }//Closing outer foreach


        }//Closing writexml method

Answer 1

您需要使用Descendants方法Elements：

XElement InkZonePath = XmlDoc.Root.Descendants("InkZoneProfile").Where(z => (string)z.Attribute("Side") == "Front").SingleOrDefault();

if(InkZonePath !=null)
   InkZonePath.AddAfterSelf(new XElement("InkZoneProfile",
               new XAttribute("Separation", x.colorname),
               new XAttribute("ZoneSettingsX", x.colorvalues)));

Answer 2

你可以改用Descendants。

List list = [1, 2, 3]
list.each { num ->
    // Do something
}

Answer 3

您当前代码的问题在于：InkZoneProfile由于JMF不是Descendants的直接子项，因此不会返回任何内容。请改用XElement InkZonePath = xdoc.Element("JMF").Descendants("InkZoneProfile") .SingleOrDefault(z => (string)z.Attribute("Side") == "Front")。

SonataAdminBundle custom rendering of text fields in list

这应该给你正确的结果： -

AddAfterSelf

在此之后，您可以使用if (InkZonePath != null) { InkZonePath.AddAfterSelf(new XElement("InkZoneProfile", new XAttribute("Separation", "Test"), new XAttribute("ZoneSettingsX", "Test2"))); } //Save XDocument xdoc.Save(@"C:\Foo.xml");添加要添加的节点。另请注意，我在此处使用了 SingleOrDefault ，但如果您有多个匹配节点，则可能会出现异常，在这种情况下请考虑使用 FirstOrDefault 。

<强>更新

添加新节点： -

var Dropdown = React.createClass({
    displayName: 'Dropdown',

    getInitialState: function () {
        return {
            options: []
        };
    },
    componentDidMount: function () {

        var component = this;

        $.ajax({
            url: 'branches.json',
            type: 'GET',
            dataType: 'JSON',
            success: function (data) {
                component.setState({
                    options: data
                });
            }
        });
    },
    handleClick: function () {

        //RUN YOUR CUSTOM HANDLER

    },
    render: function () {

        var i = 0;

        var options = this.state.options.map(function (option) {
            return React.createElement(
                'option',
                { value: option, key: i++ },
                option
            );
        });

        return React.createElement(
            'select',
            { onChange: this.handleClick },
            options
        );
    }

});

ReactDOM.render(React.createElement(Dropdown, null), document.getElementById('container'));

具有LINQ的XElement在特定节点之后添加节点

EDIT-1：整个writexml方法

3 个答案: