递归，将带有属性的xml文件解析为treeview c#答案

【问题标题】：Recursion, parsing xml file with attributes into treeview c#递归，将带有属性的xml文件解析为treeview c#
【发布时间】：2015-05-12 15:37:53
【问题描述】：

我目前正在处理一个项目，其中应用程序将接收 XML 文件并将其显示到 C# 中的树视图中。我正在使用 Visual Studio 10 编写此代码。

我无法限制属性显示的次数。我使用 foreach 循环遍历它拥有的每个属性并显示它，但它为节点下的每个子节点显示一次属性。如何修改此代码以仅显示一次属性？

using System;
using System.Collections.Generic;
using System.ComponentModel;
using System.Data;
using System.Drawing;
using System.Linq;
using System.Text;
using System.Windows.Forms;
using System.Xml;

namespace xmlToTreeview
{
    public partial class Form1 : Form
    {
        string samplePath = Application.StartupPath + @"\\sample.xml";
        public Form1()
        {
            InitializeComponent();
            DisplayTreeView(samplePath);
        }

        private void DisplayTreeView(string pathname)
        {
            try
            {
                // SECTION 1. Create a DOM Document and load the XML data into it.
                XmlDocument dom = new XmlDocument();
                dom.Load(pathname);


                // SECTION 2. Initialize the TreeView control.
                treeView1.Nodes.Clear();
                treeView1.Nodes.Add(new TreeNode(dom.DocumentElement.Name));
                TreeNode tNode = new TreeNode();
                tNode = treeView1.Nodes[0];

                // SECTION 3. Populate the TreeView with the DOM nodes.
                AddNode(dom.DocumentElement, tNode);

            }
            catch (XmlException xmlEx)
            {
                MessageBox.Show(xmlEx.Message);
            }
            catch (Exception ex)
            {
                MessageBox.Show(ex.Message);
            }
        }
        private void AddNode(XmlNode inXmlNode, TreeNode inTreeNode)
        {
            XmlNode xNode;
            TreeNode tNode;
            XmlNodeList nodeList;
            int i;

            // Loop through the XML nodes until the leaf is reached.
            // Add the nodes to the TreeView during the looping process.

            if (inXmlNode.HasChildNodes)
            {
                nodeList = inXmlNode.ChildNodes;

                for (i = 0; i <= nodeList.Count - 1; i++)
                {
                    xNode = inXmlNode.ChildNodes[i];
                    inTreeNode.Nodes.Add(new TreeNode(xNode.Name));
                    tNode = inTreeNode.Nodes[i];

                    //Check if the XmlNode has attributes
                    if (inXmlNode.Attributes.Count != 0)
                    {
                        foreach (XmlAttribute att in inXmlNode.Attributes)
                        {
                            inTreeNode.Text = inTreeNode.Text + " " + att.Name + ": " + att.Value;
                        }
                    }
                    AddNode(xNode, tNode);
                }
            }
            else
            {
                // Here you need to pull the data from the XmlNode based on the
                // type of node, whether attribute values are required, and so forth.
                inTreeNode.Text = (inXmlNode.OuterXml).Trim();
            }
            treeView1.ExpandAll();
        }
    }
}

这是我的xml的一个例子

<?xml version="1.0" encoding="utf-8"?>
<DataConfiguration xmln="abcefg12345" xmlns:xsi="12345abcefg" xsi:schemaLocation="12345abcefg12345abcefg">
  <Hosts>
    <Sites>
        <Site Name="ss">
            <Host Id="aa">
                <Address Host="www.www.com"> </Address>
            </Host>
            <Host Id="ee">
                <Address Host="www.www.com"> </Address>
            </Host>
            <Host Id="dd">
                <Address Host="www.www.com"> </Address>
            </Host> 
            <Host Id="pp">
                <Address Scheme="ppp" Host="www.www.com" Path="www.www.com"/>
                <Address Scheme="ppp" Host="www.www.com" Path="www.www.com/"/>
            </Host>
            <Host Id="ss">
                <Address Scheme="ppp" Host="www.www.com" Path="www.www.com"/>
                <Address Scheme="ppp" Host="www.www.com" Path="www.www.com"/>
            </Host> 
            <Host Id="561">
                <Address Host="www.www.com"> </Address>
            </Host> 
        </Site>
        <Site Name="hihi">
            <Host Id="cc">
                <Address Host="www.www.com"> </Address>
            </Host>
            <Host Id="sdD">
                <Address Host="www.www.com"> </Address>
            </Host>
            <Host Id="8uj">
                <Address Scheme="ppp" Host="www.www.com" Path="www.www.com"/>
                <Address Scheme="ppp" Host="www.www.com" Path="www.www.com"/>

            </Host>
            <Host Id="222">
                <Address Scheme="ppp" Host="www.www.com" Path="www.www.com"/>
                <Address Scheme="ppp" Host="www.www.com" Path="www.www.com"/>               
            </Host>
            <Host Id="hhh">
                <Address Scheme="ppp" Host="www.www.com" Path="www.www.com"/>
            </Host>
            <Host Id="hhh">
                <Address Scheme="ppp" Host="www.www.com" Path="www.www.com"/>
            </Host>             
        </Site>     
    </Sites>
            <Host Id="hhh">
                <Address Scheme="ppp" Host="www.www.com" Path="www.www.com"/>
            </Host>
            <Host Id="hhh">
                <Address Scheme="ppp" Host="www.www.com" Path="www.www.com"/>
            </Host>
            <Host Id="hhh">
                <Address Scheme="ppp" Host="www.www.com" Path="www.www.com"/>
            </Host>         
            <Host Id="hhh">
                <Address Scheme="ppp" Host="www.www.com" Path="www.www.com"/>
            </Host>

</Hosts>
<DataPools>
    <DataPool Id="sss" default="sure">
        <DataGroup Id="sss" Parent="aaa" UserCanSelectHost="sure" >
            <HostId Parent="hhhh">I'm breaking here</HostId>
            <DataSources>
                <empty/>
            </DataSources>
        </DataGroup>
        <DataGroup Id="ccc" UserCanSelectHost="whynot" >
            <HostId>God I'm breaking here again, i hope you can fix me</HostId>
            <DataSources>
                <empty/>
            </DataSources>
        </DataGroup>
        <DataGroup Id="sss" UserCanSelectHost="yessure" >
            <HostId>cry face</HostId>
                <webfg displaygroup="sss" provider="sss" id="ccc" principal="ccc" nioarc="ccc" nap="ccc" group="ccc">
                </webfg>

                <nhood port="1234"/>
            <ServerNames>
              <!-- insert comment -->
              <!-- insert comment -->
              <!-- insert comment -->
              <ServerName>myname</ServerName>
              <ServerName>yourname</ServerName>
            </ServerNames>
            <!-- insert comment -->
            <Implementations>
              <Implementation>
                <Name>yourname</Name>
                <Type>typeme</Type>
                <Assembly>visionme</Assembly>
                <Path>ohno</Path>
              </Implementation>
            </Implementations>-->
                <cfgman port="ccc" />               
                <webservice provider="ccc"  />
                <webservice provider="ccc"  />
                <webservice provider="ccc"  />
                    <parameters>
                        <useeventpush value="ccc"/>
                    </parameters>
                <webservice provider="ccc"  />
                        <pollingFrequency value="1000"/>
        </DataGroup>
    </DataPool>
    <DataGroup Id="ccc " UserCanSelectHost="ccc" >
        <DataGroup Id="ccc " UserCanSelectHost="ccc" >
            <HostId>idk</HostId>
            <DataSources>
                <empty/>
            </DataSources>
        </DataGroup>
        <DataGroup Id="ccc " UserCanSelectHost="ccc" >
            <HostId>idk</HostId>
            <DataSources>
                <empty/>
            </DataSources>
        </DataGroup>
        <DataGroup Id="default" UserCanSelectHost="true" >
            <HostId>idk</HostId>
        </DataGroup>
    </DataGroup>    
</DataPools>    
</DataConfiguration>

【问题讨论】：

标签： c# xml recursion attributes treeview

【解决方案1】：

您需要通过子节点将循环通过属性移出循环：

    private void AddNode(XmlNode inXmlNode, TreeNode inTreeNode)
    {
        // Loop through the XML nodes until the leaf is reached.
        // Add the nodes to the TreeView during the looping process.

        if (inXmlNode.HasChildNodes)
        {
            //Check if the XmlNode has attributes
            foreach (XmlAttribute att in inXmlNode.Attributes)
            {
                inTreeNode.Text = inTreeNode.Text + " " + att.Name + ": " + att.Value;
            }

            var nodeList = inXmlNode.ChildNodes;
            for (int i = 0; i < nodeList.Count; i++)
            {
                var xNode = inXmlNode.ChildNodes[i];
                var tNode = inTreeNode.Nodes[inTreeNode.Nodes.Add(new TreeNode(xNode.Name))];
                AddNode(xNode, tNode);
            }
        }
        else
        {
            // Here you need to pull the data from the XmlNode based on the
            // type of node, whether attribute values are required, and so forth.
            inTreeNode.Text = (inXmlNode.OuterXml).Trim();
        }
        treeView1.ExpandAll();
    }

更新

如果要过滤掉命名空间属性，可以加extension methods：

public static class XmlNodeExtensions
{
    public static bool IsDefaultNamespaceDeclaration(this XmlAttribute attr)
    {
        if (attr == null)
            return false;
        if (attr.NamespaceURI != "http://www.w3.org/2000/xmlns/")
            return false;
        return attr.Name == "xmlns";
    }

    public static bool IsNamespaceDeclaration(this XmlAttribute attr)
    {
        if (attr == null)
            return false;
        if (attr.NamespaceURI != "http://www.w3.org/2000/xmlns/")
            return false;
        return attr.Name == "xmlns" || attr.Name.StartsWith("xmlns:");
    }
}

然后用它来跳过不需要的XmlAttribute 实例。您还可以将XmlElement类型的所有节点的文本显式设置为名称+属性数据，而不仅仅是那些具有子元素的元素，仅将OuterXml用于文本节点：

    private void AddNode(XmlNode inXmlNode, TreeNode inTreeNode)
    {
        if (inXmlNode is XmlElement)
        {
            // An element.  Display element name + attribute names & values.
            foreach (var att in inXmlNode.Attributes.Cast<XmlAttribute>().Where(a => !a.IsNamespaceDeclaration()))
            {
                inTreeNode.Text = inTreeNode.Text + " " + att.Name + ": " + att.Value;
            }
            // Add children
            foreach (XmlNode xNode in inXmlNode.ChildNodes)
            {
                var tNode = inTreeNode.Nodes[inTreeNode.Nodes.Add(new TreeNode(xNode.Name))];
                AddNode(xNode, tNode);
            }
        }
        else
        {
            // Not an element.  Character data, comment, etc.  Display all text.
            inTreeNode.Text = (inXmlNode.OuterXml).Trim();
        }
        treeView1.ExpandAll();
    }

如果你真的想只过滤掉默认命名空间定义而留下其他的，你可以这样做：

            // An element.  Display element name + attribute names & values.
            foreach (var att in inXmlNode.Attributes.Cast<XmlAttribute>().Where(a => !a.IsDefaultNamespaceDeclaration()))
            {
                inTreeNode.Text = inTreeNode.Text + " " + att.Name + ": " + att.Value;
            }

顺便说一句，我不建议这样做，因为以下实际上意味着同一件事，即命名空间 http://somenamespace 中具有本地名称 DataConfiguration 的元素：

<ss:DataConfiguration xmlns:ss="http://somenamespace"/>
<DataConfiguration xmlns="http://somenamespace"/>

您的树将显示第一个元素的命名空间，但不显示第二个元素。

更新 2

要将XmlDeclaration 包含在树中，请将顶层循环更改为：

        treeView1.Nodes.Clear();
        foreach (XmlNode xNode in dom.ChildNodes)
        {
            var tNode = treeView1.Nodes[treeView1.Nodes.Add(new TreeNode(xNode.Name))];
            AddNode(xNode, tNode);
        }

更新 3

将循环放入DisplayTreeView 中以包含XmlDeclaration 循环：

    private void DisplayTreeView(string pathname)
    {
        try
        {
            // SECTION 1. Create a DOM Document and load the XML data into it.
            XmlDocument dom = new XmlDocument();
            dom.Load(pathname);

            // SECTION 2. Initialize the TreeView control.
            treeView1.Nodes.Clear();

            // SECTION 3. Populate the TreeView with the XML nodes.
            foreach (XmlNode xNode in dom.ChildNodes)
            {
                var tNode = treeView1.Nodes[treeView1.Nodes.Add(new TreeNode(xNode.Name))];
                AddNode(xNode, tNode);
            }
        }
        catch (XmlException xmlEx)
        {
            MessageBox.Show(xmlEx.Message);
        }
        catch (Exception ex)
        {
            MessageBox.Show(ex.Message);
        }
    }

【讨论】：

我明白了，现在可以解决问题了，谢谢！此外，我在所有子节点后面都获得了 xmlns= 命名空间，我应该如何解决这个问题？看起来它们只在我使用 OutXml 显示剩余信息时出现。还有一个问题，节点有长度吗？因为我的评论节点在节点末尾被截断了。
@StudentPlusOne - 答案已更新。节点文本的长度没有限制。确保你的树是Scrollable。
感谢您的回答，您更新的代码有效，它将删除所有包含“xmln=”的属性，但这也会从中删除部分属性，是否有不同的方法正在做？使用扩展方法也是一件很聪明的事情，我学到了很多东西！谢谢
@StudentPlusOne - "xmln=" 是您的问题中的错字，还是您真的有一个名为 xmln 的属性？标准命名空间属性前缀是xmlns，所以我认为这是一个错误。
代码是这样的，红色表示“xmln="属性重复postimg.org/image/apmg0fpl7

【解决方案2】：

尝试简单的递归算法

        static void Main(string[] args)
        {
            string input =
                "<a>" +
                   "<b>" +
                      "<c>val1</c>" +
                      "<d>val2</d>" +
                   "</b>" +
                   "<e>val3</e>" +
                   "<f>val4</f>" +
               "</a>";

            XmlDocument doc = new XmlDocument();
            doc.LoadXml(input);
            RecursiveRead(doc.DocumentElement);

        }
        static string RecursiveRead(XmlNode node)
        {
            List<string> children = new List<string>();
            bool done = false;

            if (node.HasChildNodes)
            {
                foreach (XmlNode child in node)
                {
                    children.Add(RecursiveRead(child));
                }
                Console.WriteLine("table : {0}; children : {1}", node.Name, string.Join(",", children.ToArray()));
                //string cmd = "INSERT INTO " + second + " (" + first + ") VALUES ('" + xml.Value + "')";
                //SqlCommand command = new SqlCommand(cmd, conn);
                //command.ExecuteNonQuery();
            }
            else
            {
                return node.Value;
            }
            return node.Name;
        }

【讨论】：