c# - 如何从抽象超类中引用子类的字段？

Question

类似：如何通过反射访问抽象父类中的实例字段？，但只是名义上，没有人实际使用或引用反射。

约束：

C＃

必须使用抽象类来继承

必须能够将字符串作为字段标识符传递（愿意协商）

public class ViewModel : BaseClass
{
 public Car Car { get; set; }
}
public abstract class BaseClass
{
 public object GetField(string field){
  //return Car if .GetField("Car") is called
 }
}

我认为这需要反思，但我无法完全理解它。如本例所示，如何访问 Car 字段？

Answer 1

试试这个：

[TestFixture]
public class TravisSerialisationTest
{
    [Test]
    public void GetPropertyValueTest()
    {
        var volvo = "Volvo";
        var viewModel = new ViewModel() { Car = volvo };
        var field = viewModel.GetField(() => viewModel.Car);
        Assert.AreEqual(volvo,field);
    }
}

public class ViewModel : BaseClass
{
    public string Car { get; set; }
}

public abstract class BaseClass
{
    public T GetField<T>(Expression<Func<T>> propertyExpression )
    {
        return propertyExpression.Compile().Invoke();
    }
}

Answer 2

尝试这样的事情：

    public class ViewModel : BaseClass
    {
        public string Car { get; set; }
    }
    public abstract class BaseClass
    {
        public object GetField(string name)
        {
            MemberInfo member = GetType()
                .GetMember( name, BindingFlags.Public | BindingFlags.NonPublic | BindingFlags.Instance | BindingFlags.Static )
                .FirstOrDefault();
            if(member == null)
            {
                return null;
            }
            PropertyInfo property = member as PropertyInfo;
            if(property != null)
            {
                return property.GetValue( this, null );
            }
            FieldInfo field = member as FieldInfo;
            if(field != null)
            {
                return field.GetValue( this );
            }
            return null;
         }
    }