当用户点击视图背景时,如何让键盘消失？

<div id="keyboard-overlay" style="position: fixed; top: 0; left: 0; width: 100%; height: 100%; background-color: rgba(0, 0, 0, 0.5); z-index: 999999;">
</div>

#keyboard-overlay {
  position: fixed;
  top: 0;
  left: 0;
  width: 100%;
  height: 100%;
  background-color: rgba(0, 0, 0, 0.5);
  z-index: 999999;
}

document.addEventListener('click', function(event) {
  var target = event.target;
  if (target.tagName === 'BODY') {
    var overlay = document.getElementById('keyboard-overlay');
    var overlayRect = overlay.getBoundingClientRect();
    var x = event.clientX - overlayRect.left;
    var y = event.clientY - overlayRect.top;
    var opacity = 0.5;
    if (x < overlayRect.width / 2) {
      opacity = 0;
    }
    overlay.style.opacity = opacity;
  }
});

document.addEventListener('keydown', function(event) {
  var overlay = document.getElementById('keyboard-overlay');
  if (event.key === 'E') {
    overlay.style.opacity = 0;
  }
});