写更少代码的需求

当我们重复写一些繁杂的代码，或C#的一些方法，我们就想能不能有更便捷的方法呢？当然在unity中，我们对它进行扩展。

对unity的类或C#的类进行扩展有以下两点要注意：

1、这个类必须声明为static，扩展的方法也必须要声明为static

2、在使用时，就可以直接调用扩展的方法

扩展Unity的属性

Demo

using UnityEngine;

using System.Collections;

//It is common to create a class to contain all of your

//extension methods. This class must be static.

public static class ExtensionMethods

{

    //Even though they are used like normal methods, extension

    //methods must be declared static. Notice that the first

    //parameter has the 'this' keyword followed by a Transform

    //variable. This variable denotes which class the extension

    //method becomes a part of.

    public static void ResetTransformation(this Transform trans)

    {

        trans.position = Vector3.zero;

        trans.localRotation = Quaternion.identity;

        trans.localScale = new Vector3(1, 1, 1);

    }

}

使用方法

using UnityEngine;

using System.Collections;

public class SomeClass : MonoBehaviour

{

    void Start () {

        //Notice how you pass no parameter into this

        //extension method even though you had one in the

        //method declaration. The transform object that

        //this method is called from automatically gets

        //passed in as the first parameter.

        transform.ResetTransformation();

    }

}

扩展C#的方法

为C#的集合扩展一个方法，当在调用时，就可以直接调用CFirstOrDefault

public static T CFirstOrDefault<T>(this IEnumerable<T> source)

{

    if (source != null)

    {

        foreach (T item in source)

        {

            return item;

        }

    }

    return default(T);

}

文档资料

文档：http://unity3d.com/learn/tutorials/modules/intermediate/scripting/extension-methods