由于奇怪的原因,我必须在下拉框中更改所选元素,而不是通过e.selectedIndex,而是通过模拟鼠标和按键事件。
我尝试了以下内容:
//e = the dropdown
e.focus();
//my custom function to fire mouse events. This opens the dropdown.
fireMouseEvent("mousedown", e);
//firing the key press, tried it via keydown, keypress and keyup. Nothing works.
var evt = e.ownerDocument.createEvent("KeyEvents");
evt.initKeyEvent("keydown", true, true, null, false, false, false, false, 40, 0);
evt.initKeyEvent("keypress", true, true, null, false, false, false, false, 40, 0);
evt.initKeyEvent("keyup", true, true, null, false, false, false, false, 40, 40);
e.dispatchEvent(evt);
我做错了什么或这是不可能的?
谢谢。
答案 0 :(得分:2)
这适用于大多数现代浏览器。它来自Yahoo UI Library,有几处编辑: http://developer.yahoo.com/yui/docs/UserAction.js.html
var customEvent;
var type = 'keydown';
var bubbles = true;
var cancelable = true;
var view = window;
var ctrlKey = false;
var altKey = false;
var shiftKey = false;
var metaKey = false;
var keyCode = 40;
var charCode = 40;
try {
//try to create key event
customEvent = document.createEvent("KeyEvents");
/*
* Interesting problem: Firefox implemented a non-standard
* version of initKeyEvent() based on DOM Level 2 specs.
* Key event was removed from DOM Level 2 and re-introduced
* in DOM Level 3 with a different interface. Firefox is the
* only browser with any implementation of Key Events, so for
* now, assume it's Firefox if the above line doesn't error.
*/
//TODO: Decipher between Firefox's implementation and a correct one.
customEvent.initKeyEvent(type, bubbles, cancelable, view, ctrlKey,
altKey, shiftKey, metaKey, keyCode, charCode);
} catch (ex /*:Error*/){
/*
* If it got here, that means key events aren't officially supported.
* Safari/WebKit is a real problem now. WebKit 522 won't let you
* set keyCode, charCode, or other properties if you use a
* UIEvent, so we first must try to create a generic event. The
* fun part is that this will throw an error on Safari 2.x. The
* end result is that we need another try...catch statement just to
* deal with this mess.
*/
try {
//try to create generic event - will fail in Safari 2.x
customEvent = document.createEvent("Events");
} catch (uierror /*:Error*/){
//the above failed, so create a UIEvent for Safari 2.x
customEvent = document.createEvent("UIEvents");
} finally {
customEvent.initEvent(type, bubbles, cancelable);
//initialize
customEvent.view = view;
customEvent.altKey = altKey;
customEvent.ctrlKey = ctrlKey;
customEvent.shiftKey = shiftKey;
customEvent.metaKey = metaKey;
customEvent.keyCode = keyCode;
customEvent.charCode = charCode;
}
}
//fire the event
document.dispatchEvent(customEvent);