C#泛型接口实现遇CS0314错误，求正确语法解决方案

错误提示 #

The type 'TPoint' cannot be used as type parameter 'TPoint' in the generic type or method 'IShape'. There is no boxing conversion or type parameter conversion from 'TPoint' to 'Domain.Entities.IPoint'. [Domain]csharp(CS0314)

问题根源 #

1. IContainer缺少TPoint的约束：仅约束了TShape实现IShape<TPoint>，但未明确TPoint必须实现IPoint，编译器无法推断TPoint满足IShape的泛型要求。
2. Shapes属性类型错误：TShape本身是绑定了特定TPoint的形状实现（而非泛型类型），但代码中错误地将其声明为List<TShape<TPoint>>。

修复步骤 #

1. 修正IContainer接口定义 #

补充TPoint的约束，并修正Shapes属性类型：

public interface IContainer<TShape, TPoint> 
    where TShape : IShape<TPoint>
    where TPoint : IPoint // 新增TPoint的约束
{
    public Guid Id { get; set; }
    public List<TShape> Shapes { get; set; } // 修正为List<TShape>
}

2. 修正Container模型实现 #

同步调整Shapes属性的类型：

public class Container : IContainer<Shape, Point>
{
    public Guid Id { get; set; }
    public List<Shape> Shapes { get; set; } // 修正为List<Shape>
}

修复后完整代码 #

接口定义 #

public interface IPoint
{
    public double X { get; set; }
    public double Y { get; set; }
}

public interface IShape<TPoint> where TPoint : IPoint
{
    public Guid Id { get; set; }
    public List<TPoint> Coordinates { get; set; }
}

public interface IContainer<TShape, TPoint> 
    where TShape : IShape<TPoint>
    where TPoint : IPoint
{
    public Guid Id { get; set; }
    public List<TShape> Shapes { get; set; }
}

模型实现 #

public class Point : IPoint
{
    public double X { get; set; }
    public double Y { get; set; }
}

public class Shape: IShape<Point>
{
    public Guid Id { get; set; }
    public List<Point> Coordinates { get; set; }
}

public class Container : IContainer<Shape, Point>
{
    public Guid Id { get; set; }
    public List<Shape> Shapes { get; set; }
}

内容的提问来源于stack exchange，提问作者zwoolli