为什么在keydown回调中返回false不会停止按钮单击事件? [英] Why does returning false in the keydown callback does not stop the button click event?
问题描述
我有一个按钮和以下的javascript例程。
I have a button and the following javascript routine.
$("button").keydown( function(key) {
switch(key.keyCode) {
case 32: //space
return false;
}
} );
据我了解,返回false;
会阻止按键被处理。所以 $(按钮)。click();
不会被调用。对于其他keyCodes,这可以按预期工作。例如,如果我拦截 40
,这是向下按钮,页面就不会滚动。
as I understood it, the return false;
would stop the keypress from being processed. So $("button").click();
would not be called. For other keyCodes, this works as expected. For example, if I intercept40
, which is the down button, the page is not scrolling.
我注意到了在Firefox中的这种行为。
I noticed this behavior in Firefox.
为什么返回false;
不会停止空格上的按钮点击事件? javascript规范对此有什么看法?
Why does the return false;
does not stop the button click event on space? What does the javascript spec say about this?
推荐答案
希望这能回答你的问题:
Hope this answers your question:
<input type="button" value="Press" onkeydown="doOtherStuff(); return false;">
return false;
成功取消事件浏览器,如果在HTML中的事件处理程序属性的末尾调用。据我所知,此行为未在任何地方正式指定。
return false;
successfully cancels an event across browsers if called at the end of an event handler attribute in the HTML. This behaviour is not formally specified anywhere as far as I know.
如果您通过DOM元素上的事件处理程序属性设置事件(例如 button.onkeydown = function(evt){...}
)或使用 addEventListener
/ attachEvent
(例如 button.addEventListener(keydown,function(evt){...},false)
)然后只返回 false <来自该函数的/ code>在每个浏览器中都不起作用,你需要执行
returnValue
和 preventDefault()
来自我的其他答案的东西。 preventDefault
在 DOM 2 spec ,由大多数主流现代浏览器实现。 returnValue
是特定于IE的。
If you instead set an event via an event handler property on the DOM element (e.g. button.onkeydown = function(evt) {...}
) or using addEventListener
/attachEvent
(e.g. button.addEventListener("keydown", function(evt) {...}, false)
) then just returning false
from that function does not work in every browser and you need to do the returnValue
and preventDefault()
stuff from my other answer. preventDefault
is specified in the DOM 2 spec and is implemented by most mainstream modern browsers. returnValue
is IE-specific.
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