在DOM元素上模拟按键

// 模拟按下某个按键
function simulateKeyPress(element, keyCode) {
  var event = new Event('keydown');
  event.keyCode = keyCode;
  element.dispatchEvent(event);
}

// 模拟释放某个按键
function simulateKeyRelease(element, keyCode) {
  var event = new Event('keyup');
  event.keyCode = keyCode;
  element.dispatchEvent(event);
}

// 获取需要模拟按键的DOM元素
var targetElement = document.getElementById('target');

// 模拟按下键盘上的A键
simulateKeyPress(targetElement, 65);

// 模拟释放键盘上的A键
simulateKeyRelease(targetElement, 65);