我已经使用addEventListener将事件附加到文本框。它工作得很好。当我想从另一个函数以编程方式触发事件时,问题就出现了。
我该怎么做呢?
我已经使用addEventListener将事件附加到文本框。它工作得很好。当我想从另一个函数以编程方式触发事件时,问题就出现了。
我该怎么做呢?
当前回答
值得注意的是,我们可以创建任何类型的预定义事件,并在任何地方收听。
我们并不局限于经典的内置事件。
在这个基本示例中,自定义事件interfacebuiltsuccessuserdefinedevent每3秒在self.document上分派一次
self.document。addEventListener('interfacebuiltsuccessuserdefinedevent', () => console.log("WOW"), false) setInterval(() =>{//测试 self.document。dispatchEvent(新事件(interfacebuiltsuccessuserdefinedevent)) }, 3000) //测试
有趣的事实:元素可以侦听尚未创建的事件。
其他回答
我使用JavaScript搜索了鼠标悬停时的触发点击,鼠标下拉和鼠标上拉事件。我找到了胡安·门德斯提供的答案。点击这里获取答案。
点击这里是现场演示,下面是代码:
function fireEvent(node, eventName) {
// Make sure we use the ownerDocument from the provided node to avoid cross-window problems
var doc;
if (node.ownerDocument) {
doc = node.ownerDocument;
} else if (node.nodeType == 9) {
// the node may be the document itself, nodeType 9 = DOCUMENT_NODE
doc = node;
} else {
throw new Error("Invalid node passed to fireEvent: " + node.id);
}
if (node.dispatchEvent) {
// Gecko-style approach (now the standard) takes more work
var eventClass = "";
// Different events have different event classes.
// If this switch statement can't map an eventName to an eventClass,
// the event firing is going to fail.
switch (eventName) {
case "click": // Dispatching of 'click' appears to not work correctly in Safari. Use 'mousedown' or 'mouseup' instead.
case "mousedown":
case "mouseup":
eventClass = "MouseEvents";
break;
case "focus":
case "change":
case "blur":
case "select":
eventClass = "HTMLEvents";
break;
default:
throw "fireEvent: Couldn't find an event class for event '" + eventName + "'.";
break;
}
var event = doc.createEvent(eventClass);
var bubbles = eventName == "change" ? false : true;
event.initEvent(eventName, bubbles, true); // All events created as bubbling and cancelable.
event.synthetic = true; // allow detection of synthetic events
// The second parameter says go ahead with the default action
node.dispatchEvent(event, true);
} else if (node.fireEvent) {
// IE-old school style
var event = doc.createEventObject();
event.synthetic = true; // allow detection of synthetic events
node.fireEvent("on" + eventName, event);
}
};
你想要的是这样的:
document.getElementByClassName("example").click();
使用jQuery,它是这样的:
$(".example").trigger("click");
最有效的方法是直接调用已经注册到addEventListener的相同函数。
您还可以使用CustomEvent和co触发一个假事件。
最后,一些元素如<input type="file">支持.click()方法。
如果你使用jQuery,你可以简单做到
$('#yourElement').trigger('customEventName', [arg0, arg1, ..., argN]);
然后用
$('#yourElement').on('customEventName',
function (objectEvent, [arg0, arg1, ..., argN]){
alert ("customEventName");
});
[arg0, arg1,…], argN]表示这些参数是可选的。
你可以使用下面的代码来使用Element方法触发事件:
if (!Element.prototype.triggerEvent) {
Element.prototype.triggerEvent = function (eventName) {
var event;
if (document.createEvent) {
event = document.createEvent("HTMLEvents");
event.initEvent(eventName, true, true);
} else {
event = document.createEventObject();
event.eventType = eventName;
}
event.eventName = eventName;
if (document.createEvent) {
this.dispatchEvent(event);
} else {
this.fireEvent("on" + event.eventType, event);
}
};
}
if (!Element.prototype.triggerEvent) { Element.prototype.triggerEvent = function (eventName) { var event; if (document.createEvent) { event = document.createEvent("HTMLEvents"); event.initEvent(eventName, true, true); } else { event = document.createEventObject(); event.eventType = eventName; } event.eventName = eventName; if (document.createEvent) { this.dispatchEvent(event); } else { this.fireEvent("on" + event.eventType, event); } }; } var input = document.getElementById("my_input"); var button = document.getElementById("my_button"); input.addEventListener('change', function (e) { alert('change event fired'); }); button.addEventListener('click', function (e) { input.value = "Bye World"; input.triggerEvent("change"); }); <input id="my_input" type="input" value="Hellow World"> <button id="my_button">Change Input</button>