cocos2d-x3.4，lua版本Layer封裝了onTouch事件，但沒有封裝onClick事件，遊戲按鈕資源通常是一張圖片，使用ccui.Button有點浪費；

在Layer.onTouch事件中判斷是否點選圖片比較麻煩，began事件後，移動手勢，ended事件座標點就會跟began事件不在一個點上；

檢視widget原始碼可知，按鈕點選事件是在onTouchBegan，onTouchMoved、onTouchEnded中呼叫hitTest判斷圖片矩形是否與觸控點一致，都重合時才會觸發點選事件；

這裡對Layer的onTouch修改下，讓其在限定範圍內的移動小於20畫素（容差值）才觸發點選事件，在onClick方法中再判斷是否點選目標圖片即可，這樣可以省去很多觸控判斷，也可以實現點選功能，省去ccui.Button類效能也相應得到些提升；

開啟檔案：src/cocos/framework/extends/LayerEx.lua，編輯以下程式碼：

--[[

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]]

local Layer = cc.Layer

function Layer:onTouch(callback, isMultiTouches, swallowTouches)
    if type(isMultiTouches) ~= "boolean" then isMultiTouches = false end
    if type(swallowTouches) ~= "boolean" then swallowTouches = false end
    self.touchhandler__ = true
    local began = nil
    self:registerScriptTouchHandler(function(state, ...)
        local args = {...}
        local event = {name = state}
        if isMultiTouches then
            args = args[1]
            local points = {}
            for i = 1, #args, 3 do
                local x, y, id = args[i], args[i + 1], args[i + 2]
                points[id] = {x = x, y = y, id = id}
            end
            event.points = points
        else
            event.x = args[1]
            event.y = args[2]
        end
        local bool = callback(event)
        
        --自定義新增點選事件 by jt 2016/04/20
        if self.clickCallBack ~= nil then
            if state == "began" then
                began = event
            elseif state == "ended" then
                local offset = 20--誤差值，
                local rect = cc.rect(began.x-offset,began.y-offset,began.x+offset,began.y+offset)
                if event.x >= rect.x and event.y >= rect.y and event.x <= rect.width and event.y <= rect.height then
                    self.clickCallBack(event)
                end 
            end
        end
        return bool
    end, isMultiTouches, 0, swallowTouches)
    self:setTouchEnabled(true)
    return self
end

function Layer:onClick(callback)
    self.clickCallBack = callback
    if not self.touchhandler__ then
        self:onTouch(function(event)
            return true
        end)
    end
    return self
end

function Layer:removeTouch()
    self:unregisterScriptTouchHandler()
    self:setTouchEnabled(false)
    return self
end

function Layer:onKeypad(callback)
    self:registerScriptKeypadHandler(callback)
    self:setKeyboardEnabled(true)
    return self
end

function Layer:removeKeypad()
    self:unregisterScriptKeypadHandler()
    self:setKeyboardEnabled(false)
    return self
end

function Layer:onAccelerate(callback)
    self:registerScriptAccelerateHandler(callback)
    self:setAccelerometerEnabled(true)
    return self
end

function Layer:removeAccelerate()
    self:unregisterScriptAccelerateHandler()
    self:setAccelerometerEnabled(false)
    return self
end
 

local LoginView = class("LoginView",cc.load("mvc").ViewBase)

local MotionUtil = {}

----------------------
---- @param #node
---- @param #event 
---- @return bool(是否目標觸屏物件)
function MotionUtil:checkPointToNode(node,event)
    if not node:isVisible() then return false end
    local point =  node:convertToNodeSpace(event)
    local size = node:getContentSize()
    local rect = cc.rect(0,0,size.width,size.height)
    if cc.rectContainsPoint(rect,point) then
        return true
    end 
    return false
end


function LoginView:ctor()
	self.spr_btn = cc.Sprite:create("btn_test.png"):addTo(self)--圖片路徑請自行定義修改

	--事件層
    self.touchLayer = display.newLayer()
        :onTouch(handler(self, self.onTouch))
        :onClick(handler(self, self.onClick))
        :addTo(self)
end

function LoginView:onTouch(event)
    --onTouch事件處理，比如觸控按下圖片變顏色，鬆開還原

    return true --這裡要返回true，onClick才會被呼叫
end


function LoginView:onClick(event)
	
<span style="white-space:pre">	</span>if MotionUtil:checkPointToNode(self.spr_btn,event) then
		print("點中了spr_btn")
	end

end