如何使用C＃将XML文件/字符串渲染到Winforms中的TreeView组件中

本文概述

1.了解渲染逻辑
2.完整的例子

是否在寻找一种将整个XML文档呈现到Winforms的可扩展TreeView中的方法？你当然不希望遍历每个节点, 并根据节点包含的类型和数据写很多” if” , 不是吗？相反, 我们希望与你分享一种有趣的方法, 该方法如何将任何XML文件结构自动呈现到Winforms的TreeView组件中, 这将使你的生活更轻松。
在本文中, 我们将向你展示如何使用C＃将整个XML文档呈现到Winforms应用程序的TreeView中。
1.了解渲染逻辑在此示例中, 我们将有一个treeView1变量, 该变量代表通过工具箱中的拖放添加到表单的TreeView组件。第一步, 你需要创建一个包含XML字符串的变量, 可以从本地或远程源获取该变量, 因此, 基本上由你决定如何从要呈现的XML文件中检索数据。接下来, 使用创建的实例中的LoadXml方法使用你拥有的字符串XML数据创建XmlDocument的新结构。
因为我们假设你可能已经在treeView中包含了一些数据, 所以我们将使用TreeView的Nodes.Clear方法清除渲染过程之前的所有节点。现在, 你知道, 在每个XML文件上都有一个文档名称, 用于定义文件的含义, 例如：

< ?xml version="1.0" encoding="UTF-8"?> < urlset xmlns="http://www.sitemaps.org/schemas/sitemap/0.9"> < url> < loc> https://www.sitemaps.org/< /loc> < lastmod> 2016-11-21< /lastmod> < /url> < /urlset>

在先前的XML文件上, 文档名称为urlset, 以此类推。按照我们的逻辑, 我们还将添加此节点, 并且它将基本上包含文件的所有节点。这必须手动完成, 因此使用Node.Add将节点添加到treeView中, 然后将该节点存储到变量中, 该变量将作为辅助方法AddNode的参数提供：

try{// 1. Read XML File from a local pathstring xmlString = File.ReadAllText(@"C:\Users\sdkca\Desktop\myXMLFile.xml", Encoding.UTF8); // 2. Create a XML DOM Document and load the data into it.XmlDocument dom = new XmlDocument(); dom.LoadXml(xmlString); // 3. Initialize the TreeView control. treeView1 can be created dinamically// and attached to the form or you can just drag and drop the widget from the toolbox// into the Form.// Clear any previous content of the widgettreeView1.Nodes.Clear(); // Create the root tree node, on any XML file the container (first root)// will be the DocumentElement name as any content must be wrapped in some node first.treeView1.Nodes.Add(new TreeNode(dom.DocumentElement.Name)); // 4. Create an instance of the first node in the treeview (the one that contains the DocumentElement name)TreeNode tNode = new TreeNode(); tNode = treeView1.Nodes[0]; // 5. Populate the TreeView with the DOM nodes with the helper 'AddNode' functionthis.AddNode(dom.DocumentElement, tNode); }catch (XmlException xmlEx){MessageBox.Show(xmlEx.Message); }catch (Exception ex){MessageBox.Show(ex.Message); }

辅助方法AddNode如下：

/// < summary> /// Renders a node of XML into a TreeNode. Recursive if inside the node there are more child nodes./// < /summary> /// < param name="inXmlNode"> < /param> /// < param name="inTreeNode"> < /param> private void AddNode(XmlNode inXmlNode, TreeNode inTreeNode){XmlNode xNode; TreeNode tNode; XmlNodeList nodeList; // Loop through the XML nodes until the leaf is reached.// Add the nodes to the TreeView during the looping process.// If the node has child nodes, the function will call itself.if (inXmlNode.HasChildNodes){nodeList = inXmlNode.ChildNodes; for (int i = 0; i < = nodeList.Count - 1; i++){xNode = inXmlNode.ChildNodes[i]; inTreeNode.Nodes.Add(new TreeNode(xNode.Name)); tNode = inTreeNode.Nodes[i]; 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(); }}

基本上, 它将每个XML节点转换为TreeView节点。
2.完整的例子既然我们已经解释了逻辑, 我们就可以继续执行表单了。在此示例中, 我们将在表单上有2个元素, 一个TreeView即treeView1和一个按钮即button1, 我们从工具箱中拖动它们并将其手动附加到表单上。
然后, 在我们的代码中, 我们将向按钮添加一个事件侦听器, 因此, 当用户单击一个打开的文件对话框时, 将显示一个对话框, 并允许他选择一个将呈现到树视图中的XML文件：

using System; using System.IO; using System.Text; using System.Windows.Forms; using System.Xml; namespace Sandbox{public partial class Form1 : Form{public Form1(){InitializeComponent(); }/// < summary> /// When the user clicks on the Load XML button, an open File Dialog will/// appear, allowing you to pick an XML file to render in the treeview/// < /summary> /// < param name="sender"> < /param> /// < param name="e"> < /param> private void Button1_Click(object sender, EventArgs e){OpenFileDialog saveFileDialog1 = new OpenFileDialog(); saveFileDialog1.Filter = "XML Files (*.xml)|*.xml"; saveFileDialog1.FilterIndex = 2; saveFileDialog1.RestoreDirectory = true; if (saveFileDialog1.ShowDialog() == DialogResult.OK){this.RenderXMLFile(saveFileDialog1.FileName); }}private void RenderXMLFile(string filepath){try{// 1. Read XML File from a local pathstring xmlString = File.ReadAllText(filepath, Encoding.UTF8); // 2. Create a XML DOM Document and load the data into it.XmlDocument dom = new XmlDocument(); dom.LoadXml(xmlString); // 3. Initialize the TreeView control. treeView1 can be created dinamically// and attached to the form or you can just drag and drop the widget from the toolbox// into the Form.// Clear any previous content of the widgettreeView1.Nodes.Clear(); // Create the root tree node, on any XML file the container (first root)// will be the DocumentElement name as any content must be wrapped in some node first.treeView1.Nodes.Add(new TreeNode(dom.DocumentElement.Name)); // 4. Create an instance of the first node in the treeview (the one that contains the DocumentElement name)TreeNode tNode = new TreeNode(); tNode = treeView1.Nodes[0]; // 5. Populate the TreeView with the DOM nodes.this.AddNode(dom.DocumentElement, tNode); }catch (XmlException xmlEx){MessageBox.Show(xmlEx.Message); }catch (Exception ex){MessageBox.Show(ex.Message); }}/// < summary> /// Renders a node of XML into a TreeNode. Recursive if inside the node there are more child nodes./// < /summary> /// < param name="inXmlNode"> < /param> /// < param name="inTreeNode"> < /param> 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]; this.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(); }}} }

如本文开头所述, 此方法适用于XML的每种结构, 只需加载一个随机文件, 它就会在Tree View中呈现。这种方法是通用的, 但可以轻松自定义, 因此你可以随意修改以添加条件以按数据和其他内容进行过滤。
【如何使用C＃将XML文件/字符串渲染到Winforms中的TreeView组件中】编码愉快！