/*

https://www.ptt.cc/bbs/C_Sharp/M.1618563753.A.310.html

*/

​

using System;

using System.Collections.Generic;

using System.Linq;

public class Program

{

    public static void Main()

    {

        // 股票代號陣列

        string[] stock_num = new string[] { "2330", "3008" };

​

        // 陣列 轉為 List<Stock>

        StockList stockList = new StockList(stock_num.Select(s => new Stock { Code = s }).ToList());

​

        // 新增資料

        stockList.AddStock(new Stock { Code = "0050", Name = "元大台灣50", Value = 139.25M, Qty = 3000 });

        stockList.AddStock(new Stock { Code = "VTI", Name = "Vanguard Total Stock Market ETF", Value = 217.15M, Qty = 10 });

​

        // 修改資料

        stockList.EditStock(new Stock { Code = "2330", Name = "大立光", Value = 3140M, Qty = 10 });

        stockList.EditStock(new Stock { Code = "3008", Name = "台積電", Value = 610M, Qty = 500 });

​

        // 刪除資料

        stockList.DeleteStock("VTI");

​

        // 依代碼查詢單筆資料

        Console.WriteLine(stockList.FindCodeOrDefault("2330"));

        Console.WriteLine(stockList.FindCodeOrDefault("0056")); // 找不到會回傳 null

​

        // 查詢所有資料

        foreach (var stock in stockList.QueryAll())

        {

            Console.WriteLine(stock);

        }

    }

}

​

public class StockList

{

    private List<Stock> _stockList = new List<Stock>();

​

    public StockList(List<Stock> stockList)

    {

        if (stockList != null) _stockList = stockList;

    }

​

    public Stock FindCodeOrDefault(string code)

    {

        return _stockList.Find(f => f.Code == code);

    }

​

    public bool AddStock(Stock addStock)

    {

        if (FindCodeOrDefault(addStock.Code) != null) return EditStock(addStock);

​

        _stockList.Add(addStock);

        return true;

    }

​

    public bool EditStock(Stock editStock)

    {

        var stock = FindCodeOrDefault(editStock.Code);

        if (stock == null) return false;

​

        stock.Name = editStock.Name;

        stock.Value = editStock.Value;

        stock.Qty = editStock.Qty;

        return true;

    }

​

    public bool DeleteStock(string code)

    {

        var deleteStock = _stockList.SingleOrDefault(s => s.Code == code);

​

        _stockList.Remove(deleteStock);

        return true;

    }

​

    public List<Stock> QueryAll()

    {

        return _stockList;

    }

}

​

public class Stock

{

    public string Code { get; set; }

    public string Name { get; set; }

    public decimal Value { get; set; }

    public int Qty { get; set; }

​

    public override string ToString()

    {

        return $"股票代號: {Code}、股票名稱: {Name}、股票價值: {Qty * Value}";

    }

}

​