constructor() {
    super(...arguments)
    this.state = {
      bgShadow: false,
      skuPop: false
    }
  }
  handleClickBtn() {
    this.setState(() => {
      return {
        skuPop: !this.state.skuPop,
        bgShadow: !this.state.bgShadow
      }
    })
  }

点击相应的按钮触发handleClickBtn给添加样式
bg-shadow,bg-shadow_hide是黑色背景遮罩，

sku-select__box_pop是利用transform: translateY(0%);弹出来动画
过渡效果主要是transtions

{<View onClick={this.handleClickBtn.bind(this)} className={`${bgShadow && "bg-shadow bg-shadow_hide"}`} ></View>}
<View className={`sku-select__box ${skuPop && "sku-select__box_pop"}`} >
  <SkuSelect />
</View>

.bg-shadow {
  height: 200vw;
  width: 100vw;
  position: fixed;
  top: 0;
  left: 0;
  z-index: 1;
  background: transparent;
  transition: background 0.3s ease-in; &_hide {
    background: rgba($color: #000000, $alpha: 0.5);
  }
}
.sku-select__box {
  position: fixed;
  bottom: 0;
  z-index: 1;
  transform: translateY(100%);
  transition: transform 0.3s ease-in; &_pop {
    transform: translateY(0%);
  }
}