// Global.js
var Global = {};
module.exports = Global;
// 調用的頁面
let Global = require('./Global');
Global.userToken = 'token';

例如點擊按鈕就新增一個子組件，同時需要使用ref引用子組件，我像下面這樣把ref寫在handleClick里面時，因為不在render里面，會報錯:addComponentAsRefTo(...): Only a ReactOwner can have refs.
var Father = React.createClass({
getInitalState:function(){
return {children:[]}
},
handleClick:function(){
var childrenTemp = this.state.children
this.setState{children:childrenTemp.push(<Child ref="childRef">)}
},

render:function(){
return (
<div>{this.state.children}</div>
)
}
})