如何设置vue可以读取的，对swiper事件处理程序有反应的变量

Question

我正在使用vue-awesome-swiper，我希望能够在特定条件下显示或隐藏“下一个/上一个”按钮。

具体地说，当幻灯片到达开头时，它应该显示NEXT按钮，然后到达结尾时，它应该隐藏该按钮并显示PREVIOUS按钮。

[如果可能，我希望将其设置为v-if可以挂接的变量。我该怎么做？

HTML

   <div id="swiper">
<div class="menu-tabs-icon-label">
    <swiper ref="productMenu" :options="swiperNavMenu">
        <swiper-slide>
            <div class="nav-item">
                <a href="#"> Item 1 </a>
            </div>
        </swiper-slide>
        <swiper-slide>
            <div class="nav-item">
                <a href="#"> Item 2 </a>
            </div>
        </swiper-slide>
        <swiper-slide>
            <div class="nav-item ">
                <a href="#"> Item 3 </a>
            </div>
        </swiper-slide>
    <div v-if="reachedEnd" class="swiper-button-prev" slot="button-prev"></div>
    <div v-if="reachedBeginning" class="swiper-button-next" slot="button-next"></div> 
    </swiper>
    </div>
</div>

JS

  new Vue({
  el: "#swiper",
  components: {
    LocalSwiper: VueAwesomeSwiper.swiper,
    LocalSlide: VueAwesomeSwiper.swiperSlide
  },
  data: {
    swiperNavMenu: {
      freeMode: true,
      slidesPerView: 5.75,
      on: {
        reachBeginning: function() {
          reachedBeginning = true; 
        },
        reachEnd: function() {
          reachedEnd = true;
        }
      }
    }
  },
  computed: {
    swiperA() {
      return this.$refs.productMenu.swiper;
    }
  }
});

Answer 1

您的问题与reachedBeginning和reachedEnd变量未定义有关

...
data() {
  return {
    reachedBeginning: false,
    reachedEnd: false,
    swiperNavMenu: {
      freeMode: true,
      slidesPerView: 5.75,
      on: {
        reachBeginning: ()=> {
          this.reachedBeginning = true; 
        },
        reachEnd: ()=> {
          this.reachedEnd = true;
        }
      }
    }
  }  
},
...

Answer 2

我发现答案在于将实例绑定到变量。最终代码应如下所示：

data() {
const self = this; // this is the line that fixes it all
return { 
  reachedEnd: false,
  swiperNavMenu: {
    on: {
      reachEnd: function(){
        self.reachedEnd=true
      }
    }
  }
 };
},

仍然要感谢糖的指引。