如何从阵列与不同类

Question

执行方法我有2类：

1. 类T1与字段ID。
2. 类T2继承自T1 类T2具有唯一字段SomeProperty。

此外，我有独特的属性和数组，包含两个类型的对象（T1和T2）。我需要通过这个属性获得ID，但我不知道它是如何正确实现的。

public class T_One 
{ 
    protected int id; 
    public T_One(int foo) 
    { 
     id = foo; 
    } 
    public int ID 
    { 
     get { return id; } 
    } 
} 
public class T_Two : T_One 
{ 
    protected int someProperty; 
    public T_Two(int id, int foo) : base(id) 
    { 
     someProperty = foo; 
    } 
    public int Property 
    { 
     get { return someProperty; } 
    } 
} 
//I have some solution, but I think it's BAD idea with try-catch. 
public int GetObjectIDByProperty(Array Objects, int property) 
{ 
    for(int i = 0; i < Objects.Length; i++) 
     { 
      try 
      { 
       if (((T_Two)(Objects.GetValue(i))).Property == property) 
       { 
        return ((T_Two)Objects.GetValue(i)).ID; 
       } 
      } 
      catch 
      { 
       //cause object T_one don't cast to object T_Two 
      } 
     } 
    return -1; //Object with this property didn't exist 
} 

Answer 1

您可以通过转换来访问该方法。

请事先与is运营商确认类型。其次是投以防止使用try/catch块，你也可以使用的foreach，而不是for使代码更简单：

public int GetObjectIDByProperty(Array Objects, int property) 
    { 
     foreach(T_One myT_One in Objects) 
     { 
      //Check Type with 'is' 
      if (myT_One is T_Two)) 
      { 
       //Now cast: 
       T_Two myT_Two = (T_Two)myT_One;  

       if (myT_Two.Property == property) 
        return myT_Two.ID; 
      } 
     } 

     return -1; //Object with this property didn't exist 
    }