C#使用Sleep(Int32)方法实现动态显示时间

public static void Sleep (int millisecondsTimeout);

// 使用Sleep方法动态时间
namespace _065
{
    public partial class Form1 : Form
    {
        private Label? label1;
        private static TextBox? textBox1;
 
        public Form1()
        {
            InitializeComponent();
            Load += Form1_Load;
        }
        private void Form1_Load(object? sender, EventArgs e)
        {
            // 
            // label1
            // 
            label1 = new Label
            {
                AutoSize = true,
                Location = new Point(12, 8),
                Name = "label1",
                Size = new Size(188, 17),
                TabIndex = 0,
                Text = "每秒种获取一次系统时间并显示："
            };
            // 
            // textBox1
            // 
            textBox1 = new TextBox
            {
                ForeColor = Color.Red,
                Location = new Point(12, 29),
                Multiline = true,
                Name = "textBox1",
                Size = new Size(360, 45),
                TabIndex = 1
            };
            // 
            // Form1
            // 
            AutoScaleDimensions = new SizeF(7F, 17F);
            AutoScaleMode = AutoScaleMode.Font;
            ClientSize = new Size(384, 86);
            Controls.Add(textBox1);
            Controls.Add(label1);
            Name = "Form1";
            StartPosition = FormStartPosition.CenterScreen;
            Text = "用Sleep方法动态显示时间";
            Sleep_Func();
        }
        private static void Sleep_Func()
        {
            Thread th = new(      //创建线程对象
                () =>             //使用Lambda表达式
                {
                    while (true)  //无限循环
                    {
                        Parallel.Invoke(//在窗体线程中执行
                          () =>   //使用Lambda表达式
                            {
                                textBox1!.Text = //显示系统时间
                                    DateTime.Now.ToString("F");
                            });
                        Thread.Sleep(1000);      //线程挂起1000毫秒
                    }
                })
            {
                IsBackground = true   //设置线程为后台线程
            };
            th.Start();               //开始执行线程
        }
    }
}