C# 方法中的this参数

用C#的this关键字，对Unity中的Transform类进行扩展的一个实例:

public static class GameHelper
{
    public static void FindChildRecursive(this Transform node, string name, ref Transform target)
    {
        if (!node || string.IsNullOrEmpty(name))
            return;

        if (node.name == name)
            target = node;
        else
        {
            foreach (Transform item in node)
                FindChildRecursive(item, name, ref target);
        }
    }

    public static void FindChildrenRecursive(this Transform node, string[] names, ref List<Transform> list)
    {
        if (!node || names == null)
            return;

        if (list == null)
            list = new List<Transform>();

        int index = Array.FindIndex(names, n => n == node.name);
        if (index > -1)
            list.Add(node);

        foreach (Transform item in node)
            FindChildrenRecursive(item, names, ref list);
    }
}

这里的扩展方法一般用来查找模型具体骨骼。