在选定内容上使用ComboBox.DataSource项目

using System;
using System.Collections.Generic;
using System.Windows.Forms;

public class MainForm : Form
{
    private ComboBox comboBox;

    public MainForm()
    {
        comboBox = new ComboBox();
        comboBox.Location = new System.Drawing.Point(50, 50);
        comboBox.Size = new System.Drawing.Size(200, 30);
        this.Controls.Add(comboBox);

        // 创建数据源
        List<string> items = new List<string> { "Option 1", "Option 2", "Option 3" };

        // 绑定数据源
        comboBox.DataSource = items;
    }

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

// 假设 items 是数据源列表
items.Add("New Option");
comboBox.Refresh(); // 强制刷新 ComboBox 显示