button中的文字使用setdata无法修改

<button class=‘txt’ style=‘background: rgba(255, 255, 255, 255);padding:0px 20px 0px 25px;’ bindtap=“sayfocus”>{{say}}</button>

sayfocus:function(e)

{

var that = this;

that.setData(

{say:“haha”}

)

},

当中的{{say}}在开发环境显示没问题，到手机上就没效果了