C#, Task, basic data, 非同步取得基本資料。

basic.data.repo.cs

using Dapper;
using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading.Tasks;

/// 專門載入基本資料。如：下拉選單 Select 或 AutoComplete 的項目清單。
/// C#9.0
namespace YourProject.DB.BasicData
{
    /// <summary>
    /// 專案代碼
    /// </summary>
    public record ProjectCodeName
    {
        public string ProCode { get; set; }
        public string ProName { get; set; }

        /// <summary>
        /// 顯示名稱
        /// </summary>
        public override string ToString()
        {
            return $"{ProCode}-{ProName}";
        }
    }

    /// <summary>
    /// Repository：專案代碼
    /// </summary>
    public class ProjectCodeNameRepo
    {
        ProjectCodeName[] _codeList = null;

        /// <summary>
        /// Task：載入專案代碼。
		/// ※一建構就立刻（非同步）執行。
        /// </summary>
        Task<ProjectCodeName[]> LoadTask = Task.Run(() =>
        {
            using (var conn = DBHelper.YourDB.Open())
            {
                //# GO
                var codeList = conn.Query<ProjectCodeName>(@"SELECT ProCode, ProName FROM ProjectTable(NOLOCK) ORDER BY ProCode Desc ").ToArray();
                return codeList;
            }
        });

        /// <summary>
        /// 專案代碼
        /// </summary>
        public ProjectCodeName[] CoceList
        {
            get
            {
                if (_codeList == null)
                    _codeList = LoadTask.Result; // 等 LoadTask 跑完並取值。

                return _codeList;
            }
        }

        /// <summary>
        /// AutoCompoete:SearchFunc:專案代碼
        /// </summary>
        public async Task<IEnumerable<ProjectCodeName>> SearchFunc(string keyword)
        {
            if (_codeList == null)
                _codeList = await LoadTask; // 等 LoadTask 跑完並取值。

            return _codeList.Where(c => keyword == null || c.ProName.Contains(keyword) || c.ProCode.Contains(keyword));
        }
    }
}