类型“TNestedInterface”必须可转换为“INestedInterfaceTest”才能将其用作参数“TNestedInterface”

public interface INestedInterfaceTest<TChildType>
    where TChildType : INestedInterfaceTest<TChildType>
{
     List<TChildType> children { get; set; }
}

public abstract class NestedInterfaceTest : INestedInterfaceTest<NestedInterfaceTest>
{
    public List<NestedInterfaceTest> children { get; set; }

    public TNestedInterface GetNestedInterface<TNestedInterface>()
        where TNestedInterface : NestedInterfaceTest, new()
    {
        return GateWay<TNestedInterface>.GetNestedInterface();
    }
}

public class GateWay<TNestedInterface>
    where TNestedInterface : class, INestedInterfaceTest<TNestedInterface>, new()
{
    public static TNestedInterface GetNestedInterface()
    {
        return new TNestedInterface();
    }
}

抽象类中的 GetNestedInterface 方法出现问题。 错误信息是：类型“TNestedInterface”必须可转换为“INestedInterfaceTest”，才能将其用作通用类“GateWay”中的参数“TNestedInterface”.

但是...，我的抽象类嵌套接口测试实施嵌套接口测试界面。 我在这里缺少什么？

在没有递归接口实现的情况下，以下内容确实有效：

public interface INestedInterfaceTest
{
}

public abstract class NestedInterfaceTest : INestedInterfaceTest
{
    public List<NestedInterfaceTest> children { get; set; }

    public TNestedInterface GetNestedInterface<TNestedInterface>()
        where TNestedInterface : NestedInterfaceTest, new()
    {
        return GateWay<TNestedInterface>.GetNestedInterface();
    }
}

public class GateWay<TNestedInterface>
    where TNestedInterface : class, INestedInterfaceTest, new()
{
    public static TNestedInterface GetNestedInterface()
    {
        return new TNestedInterface();
    }
}

看来递归执行的时候出了问题。

你缺少一个通用的约束GetNestedInterface<>()。改成这样：

public TNestedInterface GetNestedInterface<TNestedInterface>()
    where TNestedInterface : 
        NestedInterfaceTest, 
        INestedInterfaceTest<TNestedInterface>, // new
        new()
{
    return GateWay<TNestedInterface>.GetNestedInterface();
}

请注意，第二个约束是新的。