在IE上,我可以用jQuery(非常不标准,但工作)做到这一点
if ($.browser.msie)
$(document).keydown(function(e) { if (e.keyCode == 8) window.event.keyCode = 0;});
但是是否有可能在Firefox上运行,或者在跨浏览器上获得额外的好处呢?
郑重声明:
$(document).keydown(function(e) { if (e.keyCode == 8) e.stopPropagation(); });
什么也不做。
$(document).keydown(function(e) { if (e.keyCode == 8) e.preventDefault(); });
解决了问题,但使退格键在页面上无法使用,这比原来的行为更糟糕。
编辑:
我这样做的原因是我不是在创建一个简单的网页,而是一个大型的应用程序。仅仅因为你在错误的地方按了退格键而失去了10分钟的工作,这是非常令人恼火的。通过防止退格键返回,防止错误和讨厌用户的比例应该远远超过1000/1。
编辑2:我不是想阻止历史航行,只是想阻止事故。
EDIT3: @brentonstrines评论(因为这个问题太受欢迎了,所以移到这里):这是一个长期的“修复”,但你可以支持Chromium bug来改变webkit中的这种行为
这段代码解决了这个问题,至少在IE和Firefox中是这样(我还没有测试过其他浏览器,但如果其他浏览器也存在这个问题,我认为它有合理的工作机会)。
// Prevent the backspace key from navigating back.
$(document).unbind('keydown').bind('keydown', function (event) {
if (event.keyCode === 8) {
var doPrevent = true;
var types = ["text", "password", "file", "search", "email", "number", "date", "color", "datetime", "datetime-local", "month", "range", "search", "tel", "time", "url", "week"];
var d = $(event.srcElement || event.target);
var disabled = d.prop("readonly") || d.prop("disabled");
if (!disabled) {
if (d[0].isContentEditable) {
doPrevent = false;
} else if (d.is("input")) {
var type = d.attr("type");
if (type) {
type = type.toLowerCase();
}
if (types.indexOf(type) > -1) {
doPrevent = false;
}
} else if (d.is("textarea")) {
doPrevent = false;
}
}
if (doPrevent) {
event.preventDefault();
return false;
}
}
});
对于任何感兴趣的人,我把一个jQuery插件放在一起,它包含了toolman的(加上@MaffooClock/@cdmckay的评论)和@Vladimir Kornea的想法。
用法:
//# Disable backspace on .disabled/.readOnly fields for the whole document
$(document).disableBackspaceNavigation();
//# Disable backspace on .disabled/.readOnly fields under FORMs
$('FORM').disableBackspaceNavigation();
//# Disable backspace on .disabled/.readOnly fields under #myForm
$('#myForm').disableBackspaceNavigation();
//# Disable backspace on .disabled/.readOnly fields for the whole document with confirmation
$(document).disableBackspaceNavigation(true);
//# Disable backspace on .disabled/.readOnly fields for the whole document with all options
$(document).disableBackspaceNavigation({
confirm: true,
confirmString: "Are you sure you want to navigate away from this page?",
excludeSelector: "input, select, textarea, [contenteditable='true']",
includeSelector: ":checkbox, :radio, :submit"
});
插件:
//# Disables backspace initiated navigation, optionally with a confirm dialog
//# From: https://stackoverflow.com/questions/1495219/how-can-i-prevent-the-backspace-key-from-navigating-back
$.fn.disableBackspaceNavigation = function (vOptions) {
var bBackspaceWasPressed = false,
o = $.extend({
confirm: (vOptions === true), //# If the caller passed in `true` rather than an Object, default .confirm accordingly,
confirmString: "Are you sure you want to leave this page?",
excludeSelector: "input, select, textarea, [contenteditable='true']",
includeSelector: ":checkbox, :radio, :submit"
}, vOptions)
;
//# If we are supposed to use the bConfirmDialog, hook the beforeunload event
if (o.confirm) {
$(window).on('beforeunload', function () {
if (bBackspaceWasPressed) {
bBackspaceWasPressed = false;
return o.confirmString;
}
});
}
//# Traverse the passed elements, then return them to the caller (enables chainability)
return this.each(function () {
//# Disable backspace on disabled/readonly fields
$(this).bind("keydown keypress", function (e) {
var $target = $(e.target /*|| e.srcElement*/);
//# If the backspace was pressed
if (e.which === 8 /*|| e.keyCode === 8*/) {
bBackspaceWasPressed = true;
//# If we are not using the bConfirmDialog and this is not a typeable input (or a non-typeable input, or is .disabled or is .readOnly), .preventDefault
if (!o.confirm && (
!$target.is(o.excludeSelector) ||
$target.is(o.includeSelector) ||
e.target.disabled ||
e.target.readOnly
)) {
e.preventDefault();
}
}
});
});
}; //# $.fn.disableBackspaceNavigation
这里的其他答案已经确定,如果没有允许退格的白名单元素,就不能做到这一点。这种解决方案并不理想,因为白名单不像仅仅是文本区域和文本/密码输入那样简单,而且经常被发现是不完整的,需要更新。
However, since the purpose of suppressing the backspace functionality is merely to prevent users from accidentally losing data, the beforeunload solution is a good one because the modal popup is surprising--modal popups are bad when they are triggered as part of a standard workflow, because the user gets used to dismissing them without reading them, and they are annoying. In this case, the modal popup would only appear as an alternative to a rare and surprising action, and is therefore acceptable.
问题是onbeforeunload模式不能在用户导航离开页面时弹出(例如单击链接或提交表单时),而且我们不想开始将特定的onbeforeunload条件列入白名单或黑名单。
对于一个通用的解决方案,折衷的理想组合如下:跟踪是否按下了退格,如果是的话,只弹出onbeforeunload模式。换句话说:
function confirmBackspaceNavigations () {
// http://stackoverflow.com/a/22949859/2407309
var backspaceIsPressed = false
$(document).keydown(function(event){
if (event.which == 8) {
backspaceIsPressed = true
}
})
$(document).keyup(function(event){
if (event.which == 8) {
backspaceIsPressed = false
}
})
$(window).on('beforeunload', function(){
if (backspaceIsPressed) {
backspaceIsPressed = false
return "Are you sure you want to leave this page?"
}
})
} // confirmBackspaceNavigations
这已经在IE7+, FireFox, Chrome, Safari和Opera中进行了测试。只需将这个函数放到global.js中,并从任何您不希望用户意外丢失数据的页面调用它。
注意onbeforeunload模式只能被触发一次,所以如果用户再次按下退格键,该模式将不会再次触发。
注意,这不会触发hashchange事件,但是在这种情况下,您可以使用其他技术来防止用户意外丢失数据。