c# - 如何在传递接口(interface)时访问不同具体类的属性

Question

我正在学习 C# 并试图了解在将接口(interface)传递给使用者类时如何访问类的不同属性。请指导我。

public interface ITest
{
    int ID {get; set;}
}

public class TestA: ITest
{
    public int A {get; set;}
}

public class TestB: ITest
{
    public int B {get; set;}
}


public void Test(ITest test)
{
    // how to check/access property of TestA 
    // how to check/access property of TestB
}

尝试:

   public void Test(ITest test)
    {
        if(test.GetType() == typeof(TestA))
        {
             test.A = 45678;
        }
    }

Answer 1

如果您需要对接口(interface)的继承者做一些特定于实现的事情，请不要嗅探类型...编写一个特定于实现的方法来为您做这件事。现在调用者不需要进一步了解接口(interface):

void Main()
{
    var tests = new ITest[] { new TestA { A = 1, ID = 0 }, new TestB { B = 10, ID = 1 } };
    foreach (var test in tests)
    {
        test.DoSomeProcessing();
    }
}

public interface ITest
{
    int ID { get; set; }
    void DoSomeProcessing();
}

public class TestA : ITest
{
    public int A { get; set; }
    public int ID { get; set; }
    public void DoSomeProcessing()
    {
        Console.WriteLine("A = " + this.A);
    }
}

public class TestB : ITest
{
    public int B { get; set; }
    public int ID { get; set; }
    public void DoSomeProcessing()
    {
        Console.WriteLine("B = " + this.B);
    }
}