这在 IE 中有效，但我无法在 Opera 或 Firefox 中使用。当且仅当当前焦点是 SELECT 下拉菜单时，我想阻止退格键离开。
<html>
<body>
<select id="testselect">
<option value="1">1</option>
<option value="2">2</option>
<option value="3">3</option>
<option value="4">4</option>
</select>
<script language="javascript">
document.getElementById("testselect").onkeydown = function(e) {
if(!e) {
e = event;
}
alert(e.keyCode);
if (e.keyCode == 8 || e.keyCode == 46) {
e.returnValue = false;
e.cancelBubble = true;
if (e.stopPropagation) { e.stopPropagation(); alert("stoppropagation");}
if (e.preventDefault) { e.preventDefault(); alert("preventdefault");}
return false;
}
};
</script>
</body>
</html>
最佳答案
使用 jquery - 仅用于选择下拉菜单
$(document).ready(function(){
//for IE use keydown, for Mozilla keypress
//as described in scr: http://www.codeproject.com/KB/scripting/PreventDropdownBackSpace.aspx
$('select').keypress(function(event){if (event.keyCode == 8) {return false;}});
$('select').keydown(function(event){if (event.keyCode == 8) {return false;}});
}
对于页面中除输入控件和textarea之外的所有元素如下
<script type="text/javascript">
//set this variable according to the need within the page
var BACKSPACE_NAV_DISABLED = true;
function fnPreventBackspace(event){if (BACKSPACE_NAV_DISABLED && event.keyCode == 8) {return false;}}
function fnPreventBackspacePropagation(event){if(BACKSPACE_NAV_DISABLED && event.keyCode == 8){event.stopPropagation();}return true;}
$(document).ready(function(){
if(BACKSPACE_NAV_DISABLED){
//for IE use keydown, for Mozilla keypress
//as described in scr: http://www.codeproject.com/KB/scripting/PreventDropdownBackSpace.aspx
$(document).keypress(fnPreventBackspace);
$(document).keydown(fnPreventBackspace);
//Allow Backspace is the following controls
$('input').keypress(fnPreventBackspacePropagation);
$('input').keydown(fnPreventBackspacePropagation);
$('textarea').keypress(fnPreventBackspacePropagation);
$('textarea').keydown(fnPreventBackspacePropagation);
}
});
</script>
关于javascript - 如何防止 Backspace 在 javascript 中导航回来？，我们在Stack Overflow上找到一个类似的问题： https://stackoverflow.com/questions/1773178/