IT界影武者-程序元

最近在寫專案稍微記錄一下定義泛型的API的物件，下次懶得再回想，直接呼叫調用，順便有跟同事講這一塊自己是怎麼使用列舉說明和定義API的物件

以.Net Core Web Api為例，建立新專案，這些步驟直接略過了，定義以下要回傳的狀態以及列舉說明擴充方法

using System;
using System.Collections.Generic;
using System.ComponentModel;
using System.Linq;
using System.Threading.Tasks;

namespace WebApplication1.ViewModel
{
   
    public enum ResponseCode
    {
        [Description("成功")]
        Success = 200,
        [Description("查無此資料")]
        NotFound = 404,
    }
    public class ResponseVM<T>
    {

        /// <summary>
        /// 執行成功與否
        /// </summary>
        public bool IsSuccess { get; set; }
        /// <summary>
        /// 狀態碼
        /// </summary>
        public ResponseCode ResponseCode { get; set; }
        /// <summary>
        /// 錯誤訊息
        /// </summary>
        public string Message { get; set; }

        /// <summary>
        /// 資料本體
        /// </summary>
        public T Data { get; set; }
        public ResponseVM<T> Success()
        {
            ResponseCode = ResponseCode.Success;
            IsSuccess = true;
            Message = ResponseCode.Success.GetEnumDescription();
            return this;
        }
        public ResponseVM<T> Success(T data)
        {
            ResponseCode = ResponseCode.Success;
            IsSuccess = true;
            Data = data;
            Message = ResponseCode.Success.GetEnumDescription();
            return this;
        }

        public ResponseVM<T> Fail(ResponseCode responseCode)
        {
            ResponseCode = responseCode;
            IsSuccess = false;
            Message = responseCode.GetEnumDescription();
            return this;
        }
    }
}

上述定義了列舉狀態之後，再回頭定義擴充方法，定義取說明

namespace WebApplication1
{
    public static class MyExtensions
    {
        public static string GetEnumDescription(this Enum value)
        {
            FieldInfo fi = value.GetType().GetField(value.ToString());

            DescriptionAttribute[] attributes = (DescriptionAttribute[])fi.GetCustomAttributes(typeof(DescriptionAttribute), false);
            //若取不到屬性，則取名稱
            if ((attributes != null) && (attributes.Length > 0))
                return attributes[0].Description;
            else
                return value.ToString();
        }
    }
}

定義一個回傳的Customer資料物件

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

namespace WebApplication1.ViewModel
{
    public class ReponseCustomerVM
    {
        public string CustomerId { get; set; }

        public string CustomerName { get; set; }
    }
}

API端部分塞假資料，若是回傳成功把撈取資料的塞在Success物件裡面。

        [HttpGet]
        [Route("Customer/All")]
        public ResponseVM<List<ReponseCustomerVM>> GetCustomers()
        {
            var responseCustomers = new List<ReponseCustomerVM>();
            responseCustomers.Add(new ReponseCustomerVM
            {
                CustomerId = "001",
                CustomerName = "AA"
            });
            responseCustomers.Add(new ReponseCustomerVM
            {
                CustomerId = "002",
                CustomerName = "BB"
            });
            return new ResponseVM<List<ReponseCustomerVM>>()
                   .Success(responseCustomers);
        }

老E隨手寫