如何使用泛型类的成员创建对象集合? [英] How could I create an object collection with members from generic class?

问题描述

我想将一个成员添加到泛型类的集合中，但是它会产生两个错误，如下所示:

I want to add a member to a collection of a generic class, but it generates two errors as below:

Error   1   The best overloaded method match for ''Test.TransitionToolManager.Add(Test.StyleHandleCollection<object>)'' has some invalid arguments

Error   2   Argument 1: cannot convert from ''Test.StyleHandleCollection<Test.Plane>'' to ''Test.StyleHandleCollection<object>''

我做错了什么?
这是代码:

What am I doing wrong?
Here is the code:

namespace Test
{
    public interface ITransitionTool
    {
    }

    public class Plane : ITransitionTool
    {
    }

    public class Car : ITransitionTool
    {
    }

    public class Style
    {
        private Color mColor = new Color();
    }

    public class StyleHandle<T>
    {
        private List<T> mUserObjects = new List<T>();

        public void Adduser(T obj)
        {
            mUserObjects.Add(obj);
        }

        public void RemoveUser(T obj)
        {
            mUserObjects.Remove(obj);
        }
    }

    public class StyleHandleCollection<T>
    {
        public Dictionary<string, StyleHandle<T>> mDict = null;

        public StyleHandleCollection()
        {
            mDict = new Dictionary<string, StyleHandle<T>>();
        }
    }

    public class TransitionToolManager
    {
        private Dictionary<Type, StyleHandleCollection<object>> mCollection = null;

        public TransitionToolManager()
        {
            mCollection = new Dictionary<Type, StyleHandleCollection<object>>();
        }

        public void Add(StyleHandleCollection<object> collection)
        {
            mCollection.Add(typeof(object), collection);
        }
    }

    public class Document
    {
        private TransitionToolManager mMgr = null;

        public Document()
        {
            mMgr = new TransitionToolManager();
            StyleHandleCollection<Plane> planeStyles = new StyleHandleCollection<Plane>(); // error happens in this line...
            mMgr.Add(planeStyles);
        }
    }
}

推荐答案

您的问题似乎是当方法要求类型为Test.Plane的Test.TransitionToolManager.Add和StyleHandleCollection时，您传递了Test.TransitionToolManager.Add和StyleHandleCollection类型的StyleHandleCollection c3>.您正在尝试传递错误的集合类型.设置您的planeStyles类型为StyleHandleCollection<object>，然后查看是否仍然出现错误.

希望这会有所帮助，

Ed:)

Your issue seems to be that you pass Test.TransitionToolManager.Add a StyleHandleCollection of type Test.Plane when the method requires it to be of type object. You are trying to pass in the wrong collection type. Make your planeStyles of type StyleHandleCollection<object> and see if you still get the error.

Hope this helps,

Ed :)

这是我的解决方案，尽管它并不完美，但可以. :)

Here is my solution, though it is not perfect, it works. :)

namespace Test
{
    public interface ITransitionTool
    {
    }

    public class Plane : ITransitionTool
    {
    }

    public class Car : ITransitionTool
    {
    }

    public interface IStyleCollection
    {
    }

    public class Style
    {
        private Color mColor = new Color();
    }

    public class StyleHandle<T>
    {
        private List<T> mUserObjects = new List<T>();

        public void Adduser(T obj)
        {
            mUserObjects.Add(obj);
        }

        public void RemoveUser(T obj)
        {
            mUserObjects.Remove(obj);
        }
    }

    public class StyleHandleCollection<T> : IStyleCollection
    {
        public Dictionary<string, StyleHandle<T>> mDict = null;

        public StyleHandleCollection()
        {
            mDict = new Dictionary<string, StyleHandle<T>>();
        }
    }

    public class TransitionToolManager
    {
        private Dictionary<Type, IStyleCollection> mCollection = null;

        public TransitionToolManager()
        {
            mCollection = new Dictionary<Type, IStyleCollection>();
        }

        public void Add<T>(StyleHandleCollection<T> collection)
        {
            mCollection.Add(typeof(object), collection);
        }
    }

    public class Document
    {
        private TransitionToolManager mMgr = null;

        public Document()
        {
            mMgr = new TransitionToolManager();
            StyleHandleCollection<Plane> planeStyles = new StyleHandleCollection<Plane>();
            mMgr.Add(planeStyles);
        }
    }
}

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