cocos2d-x lua简单封装一个EditBox,添加一个label放到EditBox上面用于放占位符，并进行各种设置，代码如下：

local NewEditBox = class("NewEditBox", function (  )
    local editBoxSize = cc.size(0, 0)
    return  ccui.EditBox:create(editBoxSize,"LoginRegister/Login_tt.png")
end)

local editBox = nil--EditBox

PlaceHolderLabel = nil --占位符所在的label
PlaceHolderString = nil--占位符
PlaceHolderFontSize = nil--占位符字体大小
PlaceHolderFontName = nil --占位符字体名称
PlaceHolderColor = nil--占位符字体颜色

function NewEditBox:create(  )
    editBox = NewEditBox.new()
    PlaceHolderLabel = cc.Label:create()
    PlaceHolderLabel:addTo(editBox)
    return editBox
end

function NewEditBox:setPlaceHolder( _placeHolderContent,_placeHolderFontSize,_placeHolderFontName,_placeHolderColor)
    --获取到editBox的锚点及原点来设置占位符所在的label的位置信息
    local ap = editBox:getAnchorPoint()
    local px,py = editBox:getPosition()
    local eSize = editBox:getContentSize()

    --设置占位符所在label的位置信息
    PlaceHolderLabel:setAnchorPoint(ap)

    PlaceHolderLabel:setPosition(px,py)
    PlaceHolderLabel:setDimensions(eSize.width, eSize.height)
    --设置占位符对齐方式
    PlaceHolderLabel:setAlignment(0,1)
    --给label设置内容
    PlaceHolderLabel:setString(_placeHolderContent)
    PlaceHolderLabel:setTextColor(_placeHolderColor)
    PlaceHolderLabel:setSystemFontSize(_placeHolderFontSize)
    PlaceHolderLabel:setSystemFontName(_placeHolderFontName)

    --赋值
    PlaceHolderString = _placeHolderContent
    PlaceHolderFontSize = _placeHolderFontSize
    PlaceHolderFontName = _placeHolderFontName
    PlaceHolderColor = _placeHolderColor
end

--设置占位符内容
function NewEditBox:setPlaceHolderString( _placeHolderContent )
    -- body
    PlaceHolderString = _placeHolderContent
    PlaceHolderLabel:setString(_placeHolderContent)
end
--设置占位符的fontSize
function NewEditBox:setPlaceHolderFontSize( _placeHolderFontSize )
    -- body
    PlaceHolderFontSize = _placeHolderFontSize
    PlaceHolderLabel:setSystemFontSize(_placeHolderFontSize)
end
--设置占位符的fontName
function NewEditBox:setPlaceHolderFontName( _placeHolderFontName )
    -- body
    PlaceHolderFontSize = _placeHolderFontName
    PlaceHolderLabel:setSystemFontName(_placeHolderFontName)
end
--设置占位符的颜色
function NewEditBox:setPlaceHolderColor( _placeHolderColor )
    -- body
    PlaceHolderColor = _placeHolderColor
    PlaceHolderLabel:setTextColor(_placeHolderColor)
end

--获取到占位符所在的label
function NewEditBox:getPlaceHolderLabel()
    return PlaceHolderLabel
end

return NewEditBox