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

我只是使用了以下方法(似乎更简单):

element.blur();
element.focus();

在这种情况下,只有当值真的发生改变时才会触发事件,就像由用户执行的正常焦点轨迹丢失会触发它一样。

其他回答

HTML

<a href="demoLink" id="myLink"> myLink </a>
<button onclick="fireLink(event)"> Call My Link </button>

JS

// click event listener of the link element --------------  
document.getElementById('myLink').addEventListener("click", callLink);
function callLink(e) {
    // code to fire
}

// function invoked by the button element ----------------
function fireLink(event) {                   
    document.getElementById('myLink').click();      // script calls the "click" event of the link element 
}

你可以使用我一起编译的这个函数。

if (!Element.prototype.trigger)
  {
    Element.prototype.trigger = function(event)
    {
        var ev;

        try
        {
            if (this.dispatchEvent && CustomEvent)
            {
                ev = new CustomEvent(event, {detail : event + ' fired!'});
                this.dispatchEvent(ev);
            }
            else
            {
                throw "CustomEvent Not supported";
            }
        }
        catch(e)
        {
            if (document.createEvent)
            {
                ev = document.createEvent('HTMLEvents');
                ev.initEvent(event, true, true);

                this.dispatchEvent(event);
            }
            else
            {
                ev = document.createEventObject();
                ev.eventType = event;
                this.fireEvent('on'+event.eventType, event);
            }
        }
    }
  }

触发以下事件:

var dest = document.querySelector('#mapbox-directions-destination-input');
dest.trigger('focus');

观察事件:

dest.addEventListener('focus', function(e){
   console.log(e);
});

希望这能有所帮助!

function fireMouseEvent(obj, evtName) {
    if (obj.dispatchEvent) {
        //var event = new Event(evtName);
        var event = document.createEvent("MouseEvents");
        event.initMouseEvent(evtName, true, true, window,
                0, 0, 0, 0, 0, false, false, false, false, 0, null);
        obj.dispatchEvent(event);
    } else if (obj.fireEvent) {
        event = document.createEventObject();
        event.button = 1;
        obj.fireEvent("on" + evtName, event);
        obj.fireEvent(evtName);
    } else {
        obj[evtName]();
    }
}

var obj = document.getElementById("......");
fireMouseEvent(obj, "click");

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>

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。