使用别名时无法隐式转换类型错误

Question

我刚开始学习 C#，并且有 C++ 背景。我通过以下方式使用别名：

using CreationFunction = Func<Microsoft.Xna.Framework.Vector2, GAShooter.Entity>;

然后在我的 class 中有一个这样的字典：

private Dictionary<String, CreationFunction> creators;

然而，当我尝试在构造函数中像这样初始化它时：

creators = new Dictionary<String, CreationFunction>();

我收到一个错误。它说它不能隐式转换类型。是什么赋予了？

编辑：完整代码

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;

using CreationFunction = Func<Microsoft.Xna.Framework.Vector2, GAShooter.Entity>;

namespace GAShooter
{
    class EntityFactory
    {
        private Dictionary<String, CreationFunction> creators;

        public EntityFactory()
        {
            creators = new Dictionary<String, CreationFunction>();
        }

        public void RegisterCreator(String name, CreationFunction function)
        {
            creators[name] = function;
        }

        public Entity Create(String name)
        {
            var creator = creators[name];
            return creator();
        }
    }
}

错误的全文是：

cannot implicitly convert type 'Dictionary<string,Func <Microsoft.Xna.Framework.Vector2, GAShooter.Entity> to type 'Dictionary<String, CreationFunction>'

Answer 1

我认为问题出在您的别名定义中，您应该将其更改为

using CreationFunction = System.Func<Microsoft.Xna.Framework.Vector2, GAShooter.Entity>;

Create a using alias to make it easier to qualify an identifier to a namespace or type. The right side of a using alias directive must always be a fully-qualified type regardless of the using directives that come before it.

阅读更多 here。

使用别名时无法隐式转换类型错误

cannot implicitly convert type error when using aliases

.net

c#

generics

alias