C#使用哈希表实现XML文件查询

// Hashtable.Add(Object, Object) 方法
using System.Collections;
namespace _107_1
{
    public class SamplesHashtable
    {
 
        public static void Main()
        {
            // Creates and initializes a new Hashtable.
            var myhash = new Hashtable//集合方法
            {
                { "one", "The" },
                { "two", "quick" },
                { "three", "brown" },
                { "four", "fox" }
            };
            //等效语句，Add方法
            //var myhash = new Hashtable();
            //myhash.Add("one", "The");
            //myhash.Add("two", "quick");
            //myhash.Add("three", "brown");
            //myhash.Add("four", "fox");
 
            // Displays the Hashtable.
            Console.WriteLine("The Hashtable contains the following:");
            PrintKeysAndValues(myhash);
        }
 
        public static void PrintKeysAndValues(Hashtable myhash)
        {
            Console.WriteLine("\t-KEY-\t-VALUE-");
            foreach (DictionaryEntry de in myhash)
                Console.WriteLine($"\t{de.Key}:\t{de.Value}");
        }
    }
}
/*
运行效果：
The Hashtable contains the following:
        -KEY-   -VALUE-
        three:  brown
        four:   fox
        two:    quick
        one:    The
*/

// 用哈希表查询XML文件
using System.Collections;
using System.Xml;
 
namespace _107
{
    public partial class Form1 : Form
    {
        private Label? label1;
        private Label? label2;
        static ComboBox? comboBox1;
        static ComboBox? comboBox2;
 
        public Form1()
        {
            InitializeComponent();
            StartPosition = FormStartPosition.CenterScreen;
            Load += Form1_Load;
        }
 
        private void Form1_Load(object? sender, EventArgs e)
        {
            // 
            // label1
            // 
            label1 = new Label
            {
                AutoSize = true,
                Location = new Point(12, 21),
                Name = "label1",
                Size = new Size(68, 17),
                TabIndex = 0,
                Text = "电台名称："
            };
            // 
            // label2
            // 
            label2 = new Label
            {
                AutoSize = true,
                Location = new Point(12, 52),
                Name = "label2",
                Size = new Size(68, 17),
                TabIndex = 1,
                Text = "电台网址："
            };
            // 
            // comboBox1
            // 
            comboBox1 = new ComboBox
            {
                FormattingEnabled = true,
                Location = new Point(77, 13),
                Name = "comboBox1",
                Size = new Size(195, 25),
                TabIndex = 2
            };
            // 
            // comboBox2
            // 
            comboBox2 = new ComboBox
            {
                FormattingEnabled = true,
                Location = new Point(77, 44),
                Name = "comboBox2",
                Size = new Size(195, 25),
                TabIndex = 3
            };
            // 
            // Form1
            // 
            AutoScaleDimensions = new SizeF(7F, 17F);
            AutoScaleMode = AutoScaleMode.Font;
            ClientSize = new Size(284, 81);
            Controls.Add(comboBox2);
            Controls.Add(comboBox1);
            Controls.Add(label2);
            Controls.Add(label1);
            Name = "Form1";
            Text = "用哈希表查询XML文件";
 
            Myhash();
        }
 
        static void Myhash()
        {
            Hashtable myHashtable = SelectXML("BroadCastInfo.xml");     //使用自定义方法实例化哈希表对象
            IDictionaryEnumerator IDEnumerator = myHashtable.GetEnumerator();
            while (IDEnumerator.MoveNext())                             //循环访问哈希表
            {
                comboBox1!.Items.Add(IDEnumerator.Value!.ToString()!);  //显示电台名称
                comboBox2!.Items.Add(IDEnumerator.Key.ToString()!);     //显示电台网址
            }
            comboBox1!.SelectedIndex = comboBox2!.SelectedIndex = 0;    //设置默认选项
        }
 
        #region 在XML文件中查找电台地址及名称
        /// <summary>
        /// 在XML文件中查找电台地址及名称,BCastInfo文件存储于启动目录
        /// </summary>
        /// <param name="strPath">XML文件路径</param>
        /// <returns>Hashtable对象，用来记录找到的电台地址及名称</returns>
        static Hashtable SelectXML(string strPath)
        {
            Hashtable HTable = [];  //实例化哈希表对象
            XmlDocument doc = new();//实例化XML文档对象
            doc.Load(strPath);      //加载XML文档
            XmlNodeList xnl = doc.SelectSingleNode("BCastInfo")!.ChildNodes;//获取NewDataSet节点的所有子节点
            string strVersion = "";     //定义一个字符串，用来记录电台地址
            string strInfo = "";        //定义一个字符串，用来记录电台名称
            foreach (XmlNode xn in xnl) //遍历所有子节点
            {
                XmlElement xe = (XmlElement)xn;//将子节点类型转换为XmlElement类型
                if (xe.Name == "DInfo") //判断节点名为DInfo
                {
                    XmlNodeList xnlChild = xe.ChildNodes;   //继续获取xe子节点的所有子节点
                    foreach (XmlNode xnChild in xnlChild)   //遍历
                    {
                        XmlElement xeChild = (XmlElement)xnChild;//转换类型
                        if (xeChild.Name == "Address")
                        {
                            strVersion = xeChild.InnerText; //记录电台地址
                        }
                        if (xeChild.Name == "Name")
                        {
                            strInfo = xeChild.InnerText;    //记录电台名称
                        }
                    }
                    HTable.Add(strVersion, strInfo);        //向哈希表中添加键值
                }
            }
            return HTable;
        }
        #endregion
    }
}