我试着这样做，事情没有完全工作的原因是上下文菜单实际上被绑定到oncontextmenu事件。

function contextMenuClick(element){
    var evt = element.ownerDocument.createEvent('MouseEvents');

    var RIGHT_CLICK_BUTTON_CODE = 2; // the same for FF and IE

    evt.initMouseEvent('contextmenu', true, true,
         element.ownerDocument.defaultView, 1, 0, 0, 0, 0, false,
         false, false, false, RIGHT_CLICK_BUTTON_CODE, null);

    if (document.createEventObject){
        // dispatch for IE
       return element.fireEvent('onclick', evt)
     }
    else{
       // dispatch for firefox + others
      return !element.dispatchEvent(evt);
    }
}

为了更好地衡量，这里有一点关于参数的文档：

var myEvt = document.createEvent('MouseEvents');
myEvt.initMouseEvent(
   'click'          // event type
   ,true           // can bubble?
   ,true           // cancelable?
   ,window      // the event's abstract view (should always be window)
   ,1              // mouse click count (or event "detail")
   ,100           // event's screen x coordinate
   ,200           // event's screen y coordinate
   ,100           // event's client x coordinate
   ,200           // event's client y coordinate
   ,false         // whether or not CTRL was pressed during event
   ,false         // whether or not ALT was pressed during event
   ,false         // whether or not SHIFT was pressed during event
   ,false         // whether or not the meta key was pressed during event
   ,1             // indicates which button (if any) caused the mouse event (1 = primary button)
   ,null          // relatedTarget (only applicable for mouseover/mouseout events)
);

问得好！
我做了一些研究，似乎可以通过将button或which属性设置为2（在此处记录）来触发is shown here之类的鼠标事件，并使其成为右键单击。
也许这段代码可以工作：

function rightClick(element){
  var evt = element.ownerDocument.createEvent('MouseEvents');

  var RIGHT_CLICK_BUTTON_CODE = 2; // the same for FF and IE

  evt.initMouseEvent('click', true, true,
      element.ownerDocument.defaultView, 1, 0, 0, 0, 0, false,
      false, false, false, RIGHT_CLICK_BUTTON_CODE, null);

  if (document.createEventObject){
    // dispatch for IE
    return element.fireEvent('onclick', evt)
  }
  else{
    // dispatch for firefox + others
    return !element.dispatchEvent(evt);
  }
}

如果你不关心上下文菜单在哪里启动，这里是一个更正确的版本

function fireContextMenu(el) {
  var evt = el.ownerDocument.createEvent("HTMLEvents")
  evt.initEvent('contextmenu', true, true) // bubbles = true, cancelable = true

  if (document.createEventObject) {
    return el.fireEvent('oncontextmenu', evt)
  }
  else {
    return !el.dispatchEvent(evt)
  }
}

如果你这样做，我们可能不得不使用前一个，修复它在IE中的行为，并适当地填充screenX，screenY，clientX，clientY等

我在firefox和chrome中尝试了这个方法，但是调度contextmenu事件并不能使浏览器打开上下文菜单。事件被触发是因为我对oncontextmenu的回调被触发了，但是上下文菜单仍然没有。有人有什么想法吗，因为我使用了上面的所有代码示例？