1.html代码

<div
    class="callback float"
    @click="onClick"
    @mousedown="down"
    @touchstart="down"
    @mousemove="move"
    @touchmove="move"
    @mouseup="end"
    @touchend="end"
    ref="fu"
  >
    <!-- <p @click="callback">返回</p> -->
    <img @click="callback" src="@/assets/images/callbs.jpg" alt />
  </div>

2.再data中定义

data() {
    return {
      isLoading: false,
      flags: false, //控制使用
      position: {
        x: 0,
        y: 0,
      },
      nx: "",
      ny: "",
      dx: "",
      dy: "",
      xPum: "",
      yPum: "",
    };
  },

3.js代码

methods: {
    callback() {
      this.$router.go(-1);
    },
    onRefresh() {
      // window.location.reload();
      setTimeout((res) => {
        console.log(res);
        this.isLoading = false;
      }, 1000);
    },
    down() {
      this.flags = true;
      var touch;
      if (event.touches) {
        touch = event.touches[0];
      } else {
        touch = event;
      }
      this.position.x = touch.clientX;
      this.position.y = touch.clientY;
      this.dx = this.$refs.fu.offsetLeft;
      this.dy = this.$refs.fu.offsetTop;
    },
    move() {
      if (this.flags) {
        var touch;
        if (event.touches) {
          touch = event.touches[0];
        } else {
          touch = event;
        }
        this.nx = touch.clientX - this.position.x;
        this.ny = touch.clientY - this.position.y;
        this.xPum = this.dx + this.nx;
        this.yPum = this.dy + this.ny;
        let width = window.innerWidth - this.$refs.fu.offsetWidth; //屏幕宽度减去自身控件宽度
        let height = window.innerHeight - this.$refs.fu.offsetHeight; //屏幕高度减去自身控件高度
        this.xPum < 0 && (this.xPum = 0);
        this.yPum < 0 && (this.yPum = 0);
        this.xPum > width && (this.xPum = width);
        this.yPum > height && (this.yPum = height);
        // if (this.xPum >= 0 && this.yPum >= 0 && this.xPum<= width &&this.yPum<= height) {
        this.$refs.fu.style.left = this.xPum + "px";
        this.$refs.fu.style.top = this.yPum + "px";
        // }
        //阻止页面的滑动默认事件
        document.addEventListener(
          "touchmove",
          function () {
            event.preventDefault();
          },
          false
        );
      }
    },
    //鼠标释放时候的函数
    end() {
      this.flags = false;
    },
    onClick() {
      //在这里我是作为子组件来使用的
      this.$emit("click");
    },
  },

4.style样式

<style scoped>
.callback p {
  font-size: 16px;
  color: #fff;
  background: rgba(56, 57, 58, 0.5);
  border-radius: 50%;
  text-align: center;
  width: 50px;
  height: 50px;
  line-height: 50px;
  font-family: PingFang SC;
  font-weight: 600;
  box-shadow: 0 0 10px #fff;
}
.callback img {
  display: block;
  width: 50px;
  height: 50px;
  box-shadow: 0 0 10px rgb(133, 129, 129);
  border-radius: 50%;
  background: #fff;
}
.callback {
  position: fixed;
  top: 40px;
  left: 20px;
  z-index: 99999;
}
.float {
  position: fixed;
  right: 20px;
  top: 60%;
  touch-action: none;
  text-align: center;
  width: 50px;
  height: 50px;
  border-radius: 24px;
  line-height: 48px;
  color: white;
}
</style>