.trigger()

.trigger( eventType, extraParameters ) 返回: jQuery

描述: 为给定的事件类型执行所有处理器和行为附加到匹配的元素

  • version added: 1.0.trigger( eventType, extraParameters )

    eventType一个包含一个或多个JavaScript事件类型的字符串,比如click or submit

    extraParameters个额外的参数数组传递给事件处理程序。

  • version added: 1.3.trigger( event )

    eventA jQuery.Event 对象.

Any event handlers attached with .bind() or one of its shortcut methods are triggered when the corresponding event occurs. They can be fired manually, however, with the .trigger() method. A call to .trigger() executes the handlers in the same order they would be if the event were triggered naturally by the user:

$('#foo').bind('click', function() {
      alert($(this).text());
    });
    $('#foo').trigger('click');

As of jQuery 1.3, .trigger()ed events bubble up the DOM tree; an event handler can stop the bubbling by returning false from the handler or calling the .stopPropagation() method on the event object passed into the event. Although .trigger() simulates an event activation, complete with a synthesized event object, it does not perfectly replicate a naturally-occurring event.

To trigger handlers bound via jQuery without also triggering the native event, use .triggerHandler() instead.

When we define a custom event type using the .bind() method, the second argument to .trigger() can become useful. For example, suppose we have bound a handler for the custom event to our element instead of the built-in click event as we did above:

$('#foo').bind('custom', function(event, param1, param2) {
  alert(param1 + "\n" + param2);
});
$('#foo').trigger('custom', ['Custom', 'Event']);

The event object is always passed as the first parameter to an event handler, but if additional parameters are specified during a .trigger() call as they are here, these parameters will be passed along to the handler as well.

Note the difference between the extra parameters we're passing here and the eventData parameter to the .bind() method. Both are mechanisms for passing information to an event handler, but the extraParameters argument to .trigger() allows information to be determined at the time the event is triggered, while the eventData argument to .bind() requires the information to be already computed at the time the handler is bound.

Examples:

Example: Clicks to button #2 also trigger a click for button #1.

<!DOCTYPE html>
<html>
<head>
  <style>

button { margin:10px; }
div { color:blue; font-weight:bold; }
span { color:red; }
</style>
  <script src="http://code.jquery.com/jquery-latest.min.js"></script>
</head>
<body>
  <button>Button #1</button>
<button>Button #2</button>
<div><span>0</span> button #1 clicks.</div>

<div><span>0</span> button #2 clicks.</div>
<script>
$("button:first").click(function () {
update($("span:first"));
});
$("button:last").click(function () {
$("button:first").trigger('click');

update($("span:last"));
});

function update(j) {
var n = parseInt(j.text(), 10);
j.text(n + 1);
}
</script>

</body>
</html>

Demo:

Example: To submit the first form without using the submit() function, try:

$("form:first").trigger("submit")

Example: To submit the first form without using the submit() function, try:

var event = jQuery.Event("submit");
$("form:first").trigger(event);
if ( event.isDefaultPrevented() ) {
// Perform an action...
}

Example: To pass arbitrary data to an event:

$("p").click( function (event, a, b) {
// when a normal click fires, a and b are undefined
// for a trigger like below a refers to "foo" and b refers to "bar"

} ).trigger("click", ["foo", "bar"]);

Example: To pass arbitrary data through an event object:

var event = jQuery.Event("logged");
event.user = "foo";
event.pass = "bar";
$("body").trigger(event);

Example: Alternative way to pass data through an event object:

$("body").trigger({
type:"logged",
user:"foo",
pass:"bar"

});
设计酷,jquery1.6 api中文手册