C# 方法返回一个ParentClass对象，该对象可以是两种子类类型之一。如何公开ChildClass属性？

根据下面的代码，我有一个GetOrderPreviewSecurity（）方法返回一个安全性，它是Stock和MutualFund的父类

GetOrderPreviewSecurity（）方法实际上只将股票类型或互惠基金类型返回给安全属性。我遇到的问题是试图访问下面//注释中描述的特定于子级的属性

有没有一种方法可以强制强制转换或清理这个比“var newThing=（ChildClass）SecurityClass；”和使用newThing更干净的方法

public class Stock : Security
{
   public string Ask;
   public string Bid;
}

public class MutualFund : Security
{
   public string AssetClass;
   public string Category;
}

public Security PreviewSecurity;

  public Security GetOrderPreviewSecurity(_orderTickerText){
     //Do stuff
     if (boolean thing)
        return new Stock();
     else if (boolean thing)
        return new MutualFund();
     else
        return new Security("empty");
  }

//Some stuff

        private void ExecutePreviewOrder()
        {            
            if (!string.IsNullOrEmpty(_orderTickerText) && _orderShareQuantity > 0)
            {   
                //Returns a **Security**
                PreviewSecurity = _portfolioService.GetOrderPreviewSecurity(_orderTickerText);

                if (PreviewSecurity is Stock)
                {
                    //PreviewSecurity is still a Security type. 
                    //No Bid or Ask properties available
                    PreviewBid = PreviewSecurity.Bid; 
                    PreviewAsk = PreviewSecurity.Ask;

                }
                else if (PreviewSecurity is MutualFund)
                {
                    //PreviewSecurity is still a Security type.
                    //No AssetClass or Category propeties available 
                    PreviewAssetClass = PreviewSecurity.AssetClass;
                    PreviewCategory = PreviewSecurity.Category;
                }
            }
        }

---

我没有看到任何问题，铸造安全回来，一旦你有类型检查它

if (PreviewSecurity is Stock)
{
    PreviewBid = (Stock)PreviewSecurity.Bid; 
    PreviewAsk = (Stock)PreviewSecurity.Ask;
}
else if (PreviewSecurity is MutualFund)
{
    PreviewAssetClass = (MutualFund)PreviewSecurity.AssetClass;
    PreviewCategory = (MutualFund)PreviewSecurity.Category;
}

---

我没有看到任何问题，铸造安全回来，一旦你有类型检查它

if (PreviewSecurity is Stock)
{
    PreviewBid = (Stock)PreviewSecurity.Bid; 
    PreviewAsk = (Stock)PreviewSecurity.Ask;
}
else if (PreviewSecurity is MutualFund)
{
    PreviewAssetClass = (MutualFund)PreviewSecurity.AssetClass;
    PreviewCategory = (MutualFund)PreviewSecurity.Category;
}

---

你需要在整件事的周围有一组括号，如下所示：

if (PreviewSecurity is Stock)
{
    PreviewBid = ((Stock)PreviewSecurity).Bid;
    PreviewAsk = ((Stock)PreviewSecurity).Ask;
}
else if (PreviewSecurity is MutualFund)
{
    PreviewAssetClass = ((MutualFund)PreviewSecurity).AssetClass;
    PreviewCategory = ((MutualFund)PreviewSecurity).Category;
}

---

我认为问题在于点的优先级高于强制转换运算符，因此首先应用点运算符，然后将强制转换运算符应用于点运算符返回的任何内容

你需要在整件事的周围放上一组括号，如下所示：

if (PreviewSecurity is Stock)
{
    PreviewBid = ((Stock)PreviewSecurity).Bid;
    PreviewAsk = ((Stock)PreviewSecurity).Ask;
}
else if (PreviewSecurity is MutualFund)
{
    PreviewAssetClass = ((MutualFund)PreviewSecurity).AssetClass;
    PreviewCategory = ((MutualFund)PreviewSecurity).Category;
}

---

我认为问题在于点的优先级高于强制转换运算符，因此首先应用点运算符，然后将强制转换运算符应用于点运算符返回的任何内容

尝试：

PreviewSecurity as Stock

，

PreviewSecurity as MutualFund

尝试：

PreviewSecurity as Stock

，

PreviewSecurity as MutualFund

我同意我认为这也应该行得通。出于某种原因，我的编译器没有它。我忽略了一些括号问题？我同意我认为这也应该有效。由于某种原因，我的编译器没有它。我忽略了一些括号问题？就是这样！非常感谢，成功了！非常感谢。