c# radiobutton

using System;
using System.Windows.Forms;

namespace RadioButtonExample
{
    public class Form1 : Form
    {
        private GroupBox groupBox1;
        private RadioButton radioButton1;
        private RadioButton radioButton2;
        private Label label1;

        public Form1()
        {
            // Initialize components
            this.groupBox1 = new GroupBox();
            this.radioButton1 = new RadioButton();
            this.radioButton2 = new RadioButton();
            this.label1 = new Label();

            // Set properties for groupBox1
            this.groupBox1.Location = new System.Drawing.Point(12, 12);
            this.groupBox1.Size = new System.Drawing.Size(200, 100);
            this.groupBox1.Text = "Choose an option";

            // Set properties for radioButton1
            this.radioButton1.Location = new System.Drawing.Point(6, 20);
            this.radioButton1.Size = new System.Drawing.Size(80, 20);
            this.radioButton1.Text = "Option 1";
            this.radioButton1.CheckedChanged += new EventHandler(this.RadioButton_CheckedChanged);

            // Set properties for radioButton2
            this.radioButton2.Location = new System.Drawing.Point(6, 50);
            this.radioButton2.Size = new System.Drawing.Size(80, 20);
            this.radioButton2.Text = "Option 2";
            this.radioButton2.CheckedChanged += new EventHandler(this.RadioButton_CheckedChanged);

            // Set properties for label1
            this.label1.Location = new System.Drawing.Point(12, 120);
            this.label1.Size = new System.Drawing.Size(200, 20);
            this.label1.Text = "No option selected";

            // Add controls to groupBox1
            this.groupBox1.Controls.Add(this.radioButton1);
            this.groupBox1.Controls.Add(this.radioButton2);

            // Add controls to form
            this.Controls.Add(this.groupBox1);
            this.Controls.Add(this.label1);

            // Set form properties
            this.Text = "RadioButton Example";
            this.Size = new System.Drawing.Size(250, 200);
        }

        private void RadioButton_CheckedChanged(object sender, EventArgs e)
        {
            if (radioButton1.Checked)
            {
                label1.Text = "You selected Option 1";
            }
            else if (radioButton2.Checked)
            {
                label1.Text = "You selected Option 2";
            }
            else
            {
                label1.Text = "No option selected";
            }
        }

        [STAThread]
        static void Main()
        {
            Application.EnableVisualStyles();
            Application.SetCompatibleTextRenderingDefault(false);
            Application.Run(new Form1());
        }
    }
}

解释说明：

1. 命名空间和类：代码使用 System 和 System.Windows.Forms 命名空间，并定义了一个名为 Form1 的类，继承自 Form 类。
2. 控件初始化：在构造函数中，初始化了 GroupBox、两个 RadioButton 和一个 Label 控件，并设置了它们的属性。
3. 事件处理：为每个 RadioButton 的 CheckedChanged 事件添加了事件处理程序 RadioButton_CheckedChanged，当选择改变时更新 Label 文本。
4. 主方法：Main 方法是应用程序的入口点，创建并运行 Form1 实例。

这个示例展示了如何在 Windows Forms 应用程序中使用 RadioButton 控件，并根据用户的选择更新界面。