我遇到了类似的问题,并创建了一个当前在内部应用程序中使用的 jQuery 插件。它应该在用户完成输入后触发更改事件。
如果您不使用 jQuery,代码仍然适用于其他任何内容。
jQuery.fn.handleKeyboardChange = function(nDelay)
{
// Utility function to test if a keyboard event should be ignored
function shouldIgnore(event)
{
var mapIgnoredKeys = {
9:true, // Tab
16:true, 17:true, 18:true, // Shift, Alt, Ctrl
37:true, 38:true, 39:true, 40:true, // Arrows
91:true, 92:true, 93:true // Windows keys
};
return mapIgnoredKeys[event.which];
}
// Utility function to fire OUR change event if the value was actually changed
function fireChange($element)
{
if( $element.val() != jQuery.data($element[0], "valueLast") )
{
jQuery.data($element[0], "valueLast", $element.val())
$element.trigger("change");
}
}
// The currently running timeout,
// will be accessed with closures
var timeout = 0;
// Utility function to cancel a previously set timeout
function clearPreviousTimeout()
{
if( timeout )
{
clearTimeout(timeout);
}
}
return this
.keydown(function(event)
{
if( shouldIgnore(event) ) return;
// User pressed a key, stop the timeout for now
clearPreviousTimeout();
return null;
})
.keyup(function(event)
{
if( shouldIgnore(event) ) return;
// Start a timeout to fire our event after some time of inactivity
// Eventually cancel a previously running timeout
clearPreviousTimeout();
var $self = $(this);
timeout = setTimeout(function(){ fireChange($self) }, nDelay);
})
.change(function()
{
// Fire a change
// Use our function instead of just firing the event
// Because we want to check if value really changed since
// our previous event.
// This is for when the browser fires the change event
// though we already fired the event because of the timeout
fireChange($(this));
})
;
}
用法:
$("#my_input").handleKeyboardChange(300).change(function()
{
// value has changed!
});