vue实现可拖拽移动悬浮球

在Vue中实现一个可拖拽移动的悬浮球可以通过组合API和原生DOM事件来完成。以下是一个简单的示例：

<template>
  <div id="app">
    <div
      class="draggable"
      :style="{ top: ballPosition.y + 'px', left: ballPosition.x + 'px' }"
      @mousedown="handleMouseDown"
      @touchstart="handleTouchStart"
    >
      拖动我
    </div>
  </div>
</template>
 
<script>
import { reactive, toRefs } from 'vue';
 
export default {
  setup() {
    const state = reactive({
      isDragging: false,
      ballPosition: { x: 0, y: 0 },
    });
 
    const handleMouseMove = (event) => {
      if (state.isDragging) {
        state.ballPosition.x = event.clientX - 25;
        state.ballPosition.y = event.clientY - 25;
      }
    };
 
    const handleMouseUp = () => {
      state.isDragging = false;
      document.removeEventListener('mousemove', handleMouseMove);
      document.removeEventListener('mouseup', handleMouseUp);
    };
 
    const handleMouseDown = (event) => {
      state.isDragging = true;
      handleMouseMove(event);
      document.addEventListener('mousemove', handleMouseMove);
      document.addEventListener('mouseup', handleMouseUp);
    };
 
    const handleTouchMove = (event) => {
      if (state.isDragging) {
        state.ballPosition.x = event.touches[0].clientX - 25;
        state.ballPosition.y = event.touches[0].clientY - 25;
      }
    };
 
    const handleTouchEnd = () => {
      state.isDragging = false;
      document.removeEventListener('touchmove', handleTouchMove);
      document.removeEventListener('touchend', handleTouchEnd);
    };
 
    const handleTouchStart = (event) => {
      state.isDragging = true;
      handleTouchMove(event);
      document.addEventListener('touchmove', handleTouchMove);
      document.addEventListener('touchend', handleTouchEnd);
    };
 
    return {
      ...toRefs(state),
      handleMouseDown,
      handleTouchStart,
    };
  },
};
</script>
 
<style>
.draggable {
  width: 50px;
  height: 50px;
  position: absolute;
  cursor: pointer;
  background-color: #3498db;
  border-radius: 50%;
  color: white;
  text-align: center;
  line-height: 50px;
  z-index: 1000;
  user-select: none;
}
</style>

在这个示例中，.draggable 元素是悬浮球，它绑定了 mousedown 和 touchstart 事件处理函数，以便在用户开始拖动时进行响应。handleMouseMove 和 handleTouchMove 函数用于更新悬浮球的位置，handleMouseUp、handleTouchEnd 和 handleMouseDown 函数用于处理拖动结束。这些函数在 setup 函数中返回，以便它们可以作为事件处理函数使用。