keyup
,但这显然不会使用用户计算机的键盘重复设置。
handleKeyDown
var keyDownTimers = {};
var keyIsDown = {};
var firstKeyRepeatDelay = 1000;
var keyRepeatInterval = 100;
function handleKeyDown(keyCode) {
if (keyCode == 38) {
alert("Up");
}
}
function simpleKeyDown(evt) {
evt = evt || window.event;
var keyCode = evt.keyCode;
handleKeyDown(keyCode);
}
document.onkeydown = function(evt) {
var timer, fireKeyDown;
evt = evt || window.event;
var keyCode = evt.keyCode;
if ( keyIsDown[keyCode] ) {
// Key is already down, so repeating key events are supported by the browser
timer = keyDownTimers[keyCode];
if (timer) {
window.clearTimeout(timer);
}
keyIsDown[keyCode] = true;
handleKeyDown(keyCode);
// No need for the complicated stuff, so remove it
document.onkeydown = simpleKeyDown;
document.onkeyup = null;
} else {
// Key is not down, so set up timer
fireKeyDown = function() {
// Set up next keydown timer
keyDownTimers[keyCode] = window.setTimeout(fireKeyDown, keyRepeatInterval);
handleKeyDown(keyCode);
};
keyDownTimers[keyCode] = window.setTimeout(fireKeyDown, firstKeyRepeatDelay);
keyIsDown[keyCode] = true;
}
};
document.onkeyup = function(evt) {
evt = evt || window.event;
var keyCode = evt.keyCode;
var timer = keyDownTimers[keyCode];
if (timer) {
window.clearTimeout(timer);
}
keyIsDown[keyCode] = false;
};