c# - 如何在C#中将entitybase类型转换为实体类型

Question

我在 .NET 3.5 中尝试了以下代码，但在注释中显示的行出现异常:

无法将类型“TUnpaid”转换为“ClassLibrary1.Unpaid”

如何在 .NET 3.5 中解决这个问题？

namespace ClassLibrary1
{
    public class EntityBase
    {
        public virtual void Save<T>(T dok) where T : EntityBase, new()
        {
        }
    }

    public class Unpaid : EntityBase
    {
        public override void Save<TUnpaid>(TUnpaid dok)
        {
            // Cannot convert type 'TUnpaid' to 'ClassLibrary1.Unpaid'  
            var kup = (Unpaid)dok;
        }
    }
}

Answer 1

如果您将 EntityBase 类设为泛型，我认为您可以解决这个问题:

public class EntityBase<T>
{
    public virtual void Save<T>(T dok) where T : EntityBase<T>, new()
    {
    }
}

public class Unpaid : EntityBase<Unpaid>
{
    public override void Save<Unpaid>(Unpaid dok)
    {
        // dok is now of type Unpaid and doesn't need the cast
    }
}