vue監聽頁面元素寬度和高度變化

參考文檔：element-resize-detector的github連接

1.安裝element-resize-detector

npm install element-resize-detector

2.引入到script中

<script>
import elementResizeDetectorMaker from "element-resize-detector";
</script>

3.在mounted中使用

mounted() {
    this.watchSize();
  },
  methods: {
      watchSize() {
      const _this = this;
      var erd = elementResizeDetectorMaker();
      erd.listenTo(this.$refs.fan, (element) => { // 這裏的this.$refs.fan指定要監聽的元素對象，對應的是<div ref="fan"></div>
        var width = element.offsetWidth;
        var height = element.offsetHeight;
        _this.$nextTick(() => { // 這裏填寫監聽改變後的操做
          //const element_style = _this.$refs.gif1.style;
          //console.log("Size: " + width + "x" + height);
          //if (width > height) {
          // element_style.height = "100%";
          // element_style.width = "auto";
          //} else {
          // element_style.height = "auto";
          // element_style.width = "100%";
          //}
        });
      });
    },
  }