// wxapp.js
WxApp.prototype.reply=function(){
console.log('reply this.body:',this.body);// undefined
console.log('\n');
let content=this.body;
let message=this.wxMsg;
let xml=util.tpl(content,message);
//...
}g.js
wechat.reply.call(this);
util.js
exports.tpl=function(content,message){
console.log('contet:',content);
//...
type=content.type||type; // 报错
//...
}