我想做的是,当您按住w或s时,它应该每秒调用一次函数。但现在它只延迟第一个电话,然后每秒打12个电话。提前感谢任何愿意回答的人。我你想要更多的信息,只要问。
<!DOCTYPE html>
<script src="//ajax.googleapis.com/ajax/libs/jquery/1.11.0/jquery.min.js"></script>
<script language="javascript" type="text/javascript">
function call(direction) {
$.ajax({ url: '/' + direction });
}
</script>
<script>
document.onkeydown = function (event) {
var key_press = String.fromCharCode(event.keyCode);
var key_code = event.keyCode;
if (key_press == "W") {
direction = 'down';
} else if (key_press == "S") {
direction = 'up';
}
var update = setTimeout(function () {
call(direction)
}, 250);
}
document.onkeyup = function (event) {
clearTimeout(update);
}
</script>
使用setInterval而不是setTimeout。也可以将更新视为全局变量
var update = '';
document.onkeydown = function (event) {
var key_press = String.fromCharCode(event.keyCode);
var key_code = event.keyCode;
if (key_press == "W") {
direction = 'down';
} else if (key_press == "S") {
direction = 'up';
}
if (!update) {
update = setInterval(function () {
call(direction)
}, 1000);
}
}
document.onkeyup = function (event) {
clearInterval(update);
update = '';
}
tri this
$(document).ready(function(){
$(document).on('keydown',function(e){
// content
});
});
<script type="text/javascript">
function call(direction) {
$.ajax({ url: '/' + direction });
}
var update, direction, key = null;
document.onkeydown = function (event) {
var key_press = String.fromCharCode(event.keyCode);
var key_code = event.keyCode;
if (key_press == "W" && key != "W") {
key = "W";
direction = 'down';
update = setInterval(function () { call(direction); }, 1000);
} else if (key_press == "S" && key != "S") {
direction = 'up';
key = "S";
update = setInterval(function () { call(direction); }, 1000);
}
}
document.onkeyup = function (event) {
clearInterval(update);
}
</script>
这与debounce函数的工作原理很接近,下面是我试图解决您的问题:
function debounce(callback, ms){
var timeOutId;
window.addEventListener('keydown', function(evt){
var key = String.fromCharCode(evt.keyCode);
if(['W','S'].indexOf(key) !== -1 && !timeOutId){
timeOutId = setTimeout(function(){
callback(evt);
timeOutId = null;
}, ms);
}
});
window.addEventListener('keyup', function(evt){
clearTimeout(timeOutId);
});
}
debounce(function(){ /* your function */}, 1000);
在JSFiddle上演示。