C#拆分字符串正则表达式Regex.Split和String.Split方法

public static string[] Split (string input, string pattern);
参数
input    String
要拆分的字符串。

pattern    String
要匹配的正则表达式模式。

返回
String[]
字符串数组。

例外
ArgumentException
出现正则表达式分析错误。

ArgumentNullException
input 或 pattern 为 null。

RegexMatchTimeoutException
发生超时。 有关超时的详细信息，请参阅“备注”部分。

// 用正则表达式拆分字符串为一个子字符串数组
using System.Text.RegularExpressions;

namespace _086_2
{
    public class Example
    {
        public static void Main()
        {
            string input = @"01-31-2024";
            string pattern = @"(-)|(/)";

            foreach (string result in Regex.Split(input, pattern))
            {
                Console.WriteLine("{0}", result);
            }
        }
    }
}
// 运行结果：
/*
01
-
31
-
2024

*/

public string[] Split (params char[]? separator);

参数
separator    Char[]
分隔字符的数组、不包含分隔符的空数组或 null。

返回
String[]
一个数组，其元素包含此实例中的子字符串，这些子字符串由 separator 中的一个或多个字符分隔。 有关详细信息，请参阅“备注”部分。

// 将空格字符和制表 \t 符作为分隔符
namespace _086_1
{
    internal class Program
    {
        private static void Main(string[] args)
        {
            ArgumentNullException.ThrowIfNull(args);
            string s = "Today\tI'm going to school";
            string[] subs = s.Split(' ', '\t');

            foreach (var sub in subs)
            {
                Console.WriteLine($"Substring: {sub}");
                //Console.WriteLine("Substring: {0}", sub);//等效语句
            }
        }
    }
}
// 运行结果：
/*
Substring: Today
Substring: I'm
Substring: going
Substring: to
Substring: school

 */

// 使用Split(String, String)方法拆分字符串
// 使用String对象的Split(Char[])方法拆字符串。
using System.Text.RegularExpressions;
namespace _086
{
    public partial class Form1 : Form
    {
        private GroupBox? groupBox1;
        private Button? button2;
        private Button? button1;
        private TextBox? textBox2;
        private TextBox? textBox1;
        private Label? label2;
        private Label? label1;

        public Form1()
        {
            InitializeComponent();
            Load += Form1_Load;
        }
        private void Form1_Load(object? sender, EventArgs e)
        {
            // 
            // label1
            // 
            label1 = new Label
            {
                AutoSize = true,
                Location = new Point(6, 23),
                Name = "label1",
                Size = new Size(68, 17),
                TabIndex = 0,
                Text = "源字符串："
            };
            // 
            // label2
            // 
            label2 = new Label
            {
                AutoSize = true,
                Location = new Point(6, 48),
                Name = "label2",
                Size = new Size(68, 17),
                TabIndex = 1,
                Text = "子字符串："
            };
            // 
            // textBox1
            // 
            textBox1 = new TextBox
            {
                Location = new Point(72, 17),
                Name = "textBox1",
                Size = new Size(262, 23),
                TabIndex = 2
            };
            // 
            // textBox2
            // 
            textBox2 = new TextBox
            {
                Font = new Font("Microsoft YaHei UI", 7F),
                Location = new Point(72, 48),
                Multiline = true,
                Name = "textBox2",
                Size = new Size(181, 153),
                TabIndex = 3
            };
            // 
            // button1
            // 
            button1 = new Button
            {
                Location = new Point(259, 48),
                Name = "button1",
                Size = new Size(75, 23),
                TabIndex = 4,
                Text = "拆分1",
                UseVisualStyleBackColor = true
            };
            button1.Click += Button1_Click;
            // 
            // button2
            // 
            button2 = new Button
            {
                Location = new Point(259, 74),
                Name = "button2",
                Size = new Size(75, 23),
                TabIndex = 5,
                Text = "拆分2",
                UseVisualStyleBackColor = true
            };
            button2.Click += Button2_Click;
            // 
            // groupBox1
            // 
            groupBox1 = new GroupBox
            {
                Location = new Point(12, 12),
                Name = "groupBox1",
                Size = new Size(340, 207),
                TabIndex = 0,
                TabStop = false,
                Text = "拆分字符串"
            };
            groupBox1.Controls.Add(button2);
            groupBox1.Controls.Add(button1);
            groupBox1.Controls.Add(textBox2);
            groupBox1.Controls.Add(textBox1);
            groupBox1.Controls.Add(label2);
            groupBox1.Controls.Add(label1);
            groupBox1.SuspendLayout();

            // 
            // Form1
            // 
            AutoScaleDimensions = new SizeF(7F, 17F);
            AutoScaleMode = AutoScaleMode.Font;
            ClientSize = new Size(364, 231);
            Controls.Add(groupBox1);
            Name = "Form1";
            StartPosition = FormStartPosition.CenterScreen;
            Text = "使用正则表达式拆分字符串";
            groupBox1.ResumeLayout(false);
            groupBox1.PerformLayout();
        }
        /// <summary>
        /// 拆分1:使用正则表达式根据数字进行拆分
        /// 遍历拆分后的字符串集合
        /// </summary>
        private void Button1_Click(object? sender, EventArgs e)
        {
            if (textBox1!.Text != "")
            {
                textBox2!.Text = "";
                string[] str = MyRegex().Split(textBox1!.Text);
                foreach (string s in str)
                {
                    textBox2!.Text += s + Environment.NewLine;
                }
            }
            else
            {
                MessageBox.Show("源字符串不能为空", "拆分1");
            }
        }
        /// <summary>
        /// 拆分2
        /// </summary>
        private void Button2_Click(object? sender, EventArgs e)
        {
            if(textBox1!.Text != "")
            {
                textBox2!.Text = "";
                string s = textBox1!.Text;
                char[] separators = ['1', '2', '3', '4', '5', '6', '7', '8', '9'];

                string[] subs = s.Split(separators/*, StringSplitOptions.RemoveEmptyEntries*/);//注释后与正则方法输出相同结果

                foreach (var sub in subs)
                {
                    textBox2!.Text += sub + Environment.NewLine;
                }
            }
            else
            {
                MessageBox.Show("源字符串不能为空", "拆分2");
            }
        }

        [GeneratedRegex("[1-9]")]
        private static partial Regex MyRegex();
    }
}