C# 将从文本文件加载到 List<> 中的数组值相乘

Question

所以我有一个数组 strArray，它存储我的文本文件的值，它有 3 列。我认为这称为二维或三维数组，不确定。或者也许是一维的。我有一个名为 Inventory 的 List<>，它向其中添加了数据。

我目前有三个成功的专栏我只需要第四个。第四列是第二列和第三列相乘，就是一个总价。第二列是整数，"Number of Items"，第三列是小数，"Price"，第四列是小数，"Total Price" 即商品数量 * 价格。

我将继续 post 我的代码，我还使用四个列表框作为数据 。三列（或三个列表框）工作正常，但我只需要弄清楚第四个。

抱歉，代码量太大，我想如果我复制了所有代码，就可以更轻松地查看之前是否发生错误。 btnLoadInfo_Click 是主要问题所在的 event/method。

namespace TCSCapstone
{
public partial class frmInventory : Form
{
    List<frmInventory> Inventory = new List<frmInventory>();

    public frmInventory()
    {
        InitializeComponent();
    }

    public string ItemName { get; set; }
    public int NumberOfItems { get; set; }
    public decimal Price { get; set; }
    public decimal TotalPrice { get; set; }

    string selectedList = "";

    private void cmbList_SelectedIndexChanged(object sender, EventArgs e)
    {
        selectedList = this.cmbList.GetItemText(this.cmbList.SelectedItem);

        lstItemName.DataSource = null;
        lstNumberOfItems.DataSource = null;
        lstPrice.DataSource = null;

        lstItemName.Items.Clear();
        lstNumberOfItems.Items.Clear();
        lstPrice.Items.Clear();
        lstTotalPrices.Items.Clear();

        if (selectedList == "Creative Construction")//if the selected combo box item equals the exact string selected
        {
            selectedList = "creative"; //then the string equals creative, which is creative.txt but I add the .txt in the btnLoadInfo method
        } else if (selectedList == "Paradise Building")
        {
            selectedList = "paradise";//this is for paradise.txt
        }
        else if (selectedList == "Sitler Construction")
        {
            selectedList = "sitler";//this is for sitler.txt
        }
        else
        {
            MessageBox.Show("Please select one of the items.");
        }
    }`



        private void btnLoadInfo_Click(object sender, EventArgs e)
    {
        Inventory.Clear(); //Clears the entire Inventory List

         using (StreamReader invReader = new StreamReader(selectedList + 
 ".txt"))
         {
             while (invReader.Peek() >= 0)
             {
                 string str;
                 string[] strArray;
                 str = invReader.ReadLine();

                 strArray = str.Split(',');
                 frmInventory currentItem = new frmInventory();

                 currentItem.ItemName = strArray[0];
                 currentItem.NumberOfItems = int.Parse(strArray[1]);
                 currentItem.Price = 
 decimal.Parse(strArray[2]);

                 strArray[1].
                 currentItem.TotalPrice = decimal.Parse(strArray[1] * 
strArray[2]);

                 Inventory.Add(currentItem);

             }
         }


         displayLists(); //Calls the displayLists method to update list 
//boxes at the end of the button click event
     }//end of btnLoadInfo

     void displayLists()
     {
         //Resets the listboxes datasources by setting them to null
         lstItemName.DataSource = null;
         lstNumberOfItems.DataSource = null;
         lstPrice.DataSource = null;

         lstItemName.Items.Clear();
         lstNumberOfItems.Items.Clear();
         lstPrice.Items.Clear();
         lstTotalPrices.Items.Clear();

         lstItemName.DisplayMember = "ItemName";
         lstItemName.ValueMember = "";
         lstItemName.DataSource = Inventory;

         lstNumberOfItems.DisplayMember = "NumberOfItems";
         lstNumberOfItems.ValueMember = "";
         lstNumberOfItems.DataSource = Inventory;

         lstPrice.DisplayMember = "Price";
         lstPrice.ValueMember = "";
         lstPrice.DataSource = Inventory;
     }

Answer 1

您正在尝试将两个字符串相乘。相反，乘以您已经解析的数值：

currentItem.TotalPrice = currentItem.NumberOfItems * currentItem.Price;

Answer 2

您的 TotalPrice 属性应该是一个数学方程式，而不是您独立于商品数量及其价格设置的东西。

将属性更改为：

public decimal TotalPrice{
  get{ return NumberOfItems * Price; }
}

删除循环中设置 TotalPrice 的行；不再需要，因为您已经设置了商品价格和商品数量；总价内在地遵循这些

C# 将从文本文件加载到 List<> 中的数组值相乘

C# Multiplying the values of an array together which are loaded from a textfile into a List<>

c#

arrays

streamreader

filereader