cocos2dx-lua中handler解析

先看一段代码：

local c=c or {}

function c:onTouch()
    print "test in onTouch"
end

function handler(obj, method)
    return function(...)
        return method(obj, ...)
    end
end

测试：

1：

print(handler(c,c.onTouch))
print(c.onTouch(c))

输出

function: 0x7f0d0884ae00                                                                                                

test in onTouch

2:

print(handler(c,c.onTouch))
print((function()c.onTouch(c)end))

输出

function: 0x7f44d8d2ab40                                                                                                

function: 0x7f44d8d29e30 

 

结论：

handler只不过是对method进行封装 套了一层匿名function并返回该匿名方法

所以handler(c,c.onTouch)()等价于c:onTouch()等价于c.onTouch(c)也同样等价于(function()c.onTouch(c)end())()