未选择的按钮class为detail-btn，选择后class为detail-btn detail-selected （注意图片变换下）

html:

<div class="detail-btn" @click="chooseOrder($event)"></div>


css:

.detail-btn{
    width: .43rem;
    height: .45rem;
    background: url(../images/list-no.png) no-repeat;
    background-size: 98%;
}
.detail-selected{
    background: url(../images/list-select.png) no-repeat;
    background-size: 98%;
}


js:

                chooseOrder:function(e){
                        if (e.target.className.indexOf("detail-selected") == -1) {
                            e.target.className = "detail-btn detail-selected"; //切换按钮样式
                           //写逻辑
                        } else {
                            e.target.className = "detail-btn";//切换按钮样式
                           //写逻辑
                        }
                 },