How to use addEventListener

问题

I was making a script that creates div elements each time a button is pressed. Originally I had the function called inline with the onclick attribute, but jslint doesn't like that so I moved it out and instead tried to use addEventListener("click",function());

I've never used addEventListener() before so I'm not even sure I am using it correctly.

The problem is that it creates one div when the page loads and won't do anything when the button is pressed.

Thank you in advance.

here is what I have:

<body>
<form>
    <textarea id="a"></textarea>    
    <br>
    <input value="button" type="button">
</form>
<div id="content">
</div>
<script>
    /*jslint browser:true */
    function createEntry(text) {
        "use strict";

        var div = document.createElement("div");
        div.setAttribute("class", "test");
        document.getElementById("content").appendChild(div);
    }
    var input = document.getElementsByTagName("input")[0];
    input.addEventListener("click", createEntry(document.getElementById('a').value));
</script>

回答1:

Change the event listener like this

input.addEventListener("click", function(){
    createEntry(document.getElementById('a').value);
});

as it stands, you're passing the result of createEntry as an event listener, not the function itself

More information here:

https://developer.mozilla.org/en/docs/DOM/element.addEventListener

回答2:

Change this line

input.addEventListener("click", createEntry(document.getElementById('a').value));

into

input.addEventListener("click", function(){
createEntry(document.getElementById('a').value);
});

回答3:

Try using a JavaScript library like jQuery for event handling and DOM manipulation, to be browser safe and for uniformity.

You can use the event handlers in jQuery like the following:

$(<element_selector>).on("click", function (event) {
     // your code here...
});

来源：https://stackoverflow.com/questions/13771025/how-to-use-addeventlistener

标签

javascript

click

addeventlistener