react className 样式控制

1.<div className={ "formbox " + this.state.classArr }></div>

2. this.state.classArr = [];

<div className={ "formbox  " + this.state.classArr.jion("  ") }> </div>

this.state.classArr.pop()

this.state.classArr.push(".demo")  可以更改class  页面也会出发更新

Like (){
this.setState({
　　isLike:!this.state.isLike
});
console.log(11);
}

<span className="like" onClick={ this.Like }><span className={ this.state.isLike ? 'active iconfont' : 'iconfont' } >&#xe870;</span>喜欢</span>