区域外事件捕捉：如何让进度条拖动到区域外仍触发鼠标移动事件？

const button = document.querySelector('button');
button?.addEventListener('mousedown', handleMoveStart);

let startPoint: { x: number; y: number } | undefined;

let originalOnSelectStart: Document['onselectstart'] = null;

function handleMoveStart(e: MouseEvent) {
  e.stopPropagation();
  if (e.ctrlKey || [1, 2].includes(e.button)) return;
  window.getSelection()?.removeAllRanges();

  e.stopImmediatePropagation();
  window.addEventListener('mousemove', handleMoving);
  window.addEventListener('mousedown', handleMoveEnd);

  originalOnSelectStart = document.onselectstart;
  document.onselectstart = () => false;

  startPoint = { x: e.x, y: e.y };
}

function handleMoving(e: MouseEvent) {
  if (!startPoint) return;
  // DO Something
}

function handleMoveEnd(e: MouseEvent) {
  window.removeEventListener('mousemove', handleMoving);
  window.removeEventListener('mousedown', handleMoveEnd);
  startPoint = undefined;
  if (document.onselectstart !== originalOnSelectStart) {
    document.onselectstart = originalOnSelectStart;
  }
}