[英]How could I iterate through list of abstract type, containing non-abstract types derived from that abstract class?
我需要遍歷我創建的列表,但不能訪問里面的對象。 我嘗試了一些不同的功能,但沒有任何效果,我擔心我使用了錯誤的工具來完成這項工作。
namespace WholesaleApp
{
internal class Program : Wholesale
{
static string filePath = "C:\\Wholesale.txt";
static void Main(string[] args)
{
List<Merchandise> productList = new List<Merchandise>();
productList = ReadFromFile(filePath);
foreach(Merchandise merchandise in productList)
{
//this is where I'm trying to access objects inside and display them
}
}
}
}
這是我的抽象 class:
namespace WholesaleApp
{
internal abstract class Merchandise
{
public string merchandiseName { get; set; }
public int merchandiseAmount { get; set; }
public Merchandise(string name, int amount)
{
merchandiseName = name;
merchandiseAmount = amount;
}
}
}
這是從Merchandise
抽象 class 派生的三個類之一:
namespace WholesaleApp
{
internal class MerchandiseClothing : Merchandise
{
public string clothSize { get; set; }
public string clothType { get; set; }
public MerchandiseClothing(string _clothType, string _clothSize, string name, int amount) : base(name, amount)
{
clothType = _clothType;
clothSize = _clothSize;
}
public void ReturnAll()
{
Console.Write(merchandiseName+" of type: "+clothSize+" in amount: "+merchandiseAmount+ " and jeep status is: "+clothType);
}
}
}
最后,我的 function 將所有內容添加到最終列表中:
namespace WholesaleApp
{
internal class Wholesale
{
static public List<Merchandise> ReadFromFile(string filePath)
{
List<Merchandise> result = new List<Merchandise>();
string line;
StreamReader reader = null!;
try
{
reader = new StreamReader(filePath);
line = reader.ReadLine()!;
while (line != null)
{
string[] words = line.Split(';');
if (words[0] == "MerchandiseComputer")
{
result.Add(new MerchandiseComputer(words[1], words[2], Int32.Parse(words[3])));
}
else if (words[0] == "MerchandiseCarParts")
{
result.Add(new MerchandiseCarParts(bool.Parse(words[1]), words[3], words[2], Int32.Parse(words[4])));
}
else if (words[0] == "MerchandiseClothing")
{
result.Add(new MerchandiseClothing(words[1], words[2], words[3], Int32.Parse(words[4])));
}
line = reader.ReadLine()!;
}
}
catch (Exception e)
{
Console.WriteLine(e.Message);
}
finally
{
reader.Close();
}
return result;
}
}
}
應該可以在這里迭代已經迭代對象。 如果您想使用每個特定 class 中的特定字段,您可以在此處檢查類型並做任何您想做的事情。 例如:
foreach (Merchandise merchandise in productList)
{
if (merchandise is MerchandiseClothing clothing)
{
Console.WriteLine(clothing.clothSize); //Can be use any field from Clothing class
Console.WriteLine(clothing.merchandiseAmount); //And also from parent
}
else if (merchandise is MerchandiseComputer computer)
{
//Do what you want
}
}
但是,最好在Merchandise
class 中創建像WriteToConsole
這樣的抽象方法,並在每個實現中覆蓋它。 就像MerchandiseClothing
class 中的ReturnAll
方法
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