js 拖拽div排列排序

<div id="container">
  <div class="item" draggable="true">Item 1</div>
  <div class="item" draggable="true">Item 2</div>
  <div class="item" draggable="true">Item 3</div>
  <div class="item" draggable="true">Item 4</div>
</div>

#container {
  display: flex;
  flex-direction: column;
}

.item {
  padding: 10px;
  margin: 5px;
  border: 1px solid #ccc;
  cursor: grab;
}

const container = document.getElementById('container');
let draggedItem = null;

container.addEventListener('dragstart', (event) => {
  draggedItem = event.target;
  event.dataTransfer.effectAllowed = 'move';
});

container.addEventListener('dragover', (event) => {
  event.preventDefault();
  const overItem = event.target;
  if (overItem && overItem.classList.contains('item') && overItem !== draggedItem) {
    const rect = overItem.getBoundingClientRect();
    const relY = event.clientY - rect.top;
    const height = rect.bottom - rect.top;
    const parentRect = container.getBoundingClientRect();
    const offset = relY - height / 2;
    if (offset < parentRect.height / 2) {
      container.insertBefore(draggedItem, overItem);
    } else {
      container.insertBefore(draggedItem, overItem.nextSibling);
    }
  }
});

container.addEventListener('dragend', () => {
  draggedItem = null;
});