Question

问题

所以，我的问题是，当我调用window.onload = app.setup时，我想将0添加到min和sec类的元素中。

我得到了什么

<h1><span class="min"></span> : <span class="sec"></span></h1>

我想要什么

<h1><span class="min">0</span> : <span class="sec">0</span></h1>

// main class
class Main {
    constructor() {
        // stores time
        this.mins = 0;
        this.secs = 0;
        // stores users inputs
        this.workHours = null;
        this.restHours = null;
    }

    // sets up html    
    setup() {
        document.getElementsByClassName("min").innerHTML = toString(this.mins);
        document.getElementsByClassName("sec").innerHTML = toString(this.secs);
    }
}

let app = new Main();

window.onload = app.setup;

@import url('https://fonts.googleapis.com/css?family=Roboto:400,500');

* {
    margin: 0;
    padding: 0;
}

*::selection {
    background-color: #333;
    color: #fff;
}

.container {
    width: 60%;
    margin: 0 auto;
}

.clock {
    padding: 20px;
    text-align: center;
}

.clock h1 {
    color: #333;
    font: 500 1.8em Roboto;
}

.controls {
    text-align: center;
    padding: 20px;
}

.inputs input{
    width: 40%;
    margin: 10px;
    padding: 14px;
    border: none;
    outline: none;
    font: 400 1em Roboto;
    border-bottom: 3px solid #fff;
    transition: border-color 200ms ease-in-out;
    -webkit-transition: border-color 200ms ease-in-out;
    -o-transition: border-color 200ms ease-in-out;
    -moz-transition: border-color 200ms ease-in-out
}

.inputs input:focus {
    border-color: #333;
}

.buttons {
    padding: 10px;
}

.buttons button {
    padding: 15px;
    width: 20%;
    margin: 10px;
    border: none;
    outline: none;
    color: #fff;
    font: 500 1em Roboto;
    cursor: pointer
}

.buttons button:nth-child(1) {
    background-color: rgba(0, 0, 200, 0.6);
}

.buttons button:nth-child(2) {
    background-color: rgba(0, 200, 0, 0.6);
}

.buttons button:nth-child(3) {
    background-color: rgba(200, 0, 0, 0.6);
}

<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <meta http-equiv="X-UA-Compatible" content="ie=edge">
    <title>Pomodoro Clock</title>
</head>
<body>
    <div class="container">

        <div class="clock">
            <h1><span class="min"></span> : <span class="sec"></span></h1>
        </div>

        <div class="controls">
            <div class="inputs">
                <input type="text" placeholder="Minutes of work">
                <input type="text" placeholder="Minutes of rest">
            </div>

            <div class="buttons">
                <button class="play"><i class="fa fa-play" aria-hidden="true"></i></button>
                <button class="pause"><i class="fa fa-pause" aria-hidden="true"></i></button>
                <button class="reset"><i class="fa fa-refresh" aria-hidden="true"></i></button>
            </div>
        </div>

    </div>

    <script src="https://use.fontawesome.com/e99695fe86.js"></script>
</body>
</html>

Answer 1

document.getElementsByClassName返回HTMLCollection（多个元素）而不只是一个元素。

试试这个：

setup() {
    document.getElementsByClassName("min")[0].innerHTML = this.mins.toString();
    document.getElementsByClassName("sec")[0].innerHTML = this.secs.toString();
}

另外，因为您尝试访问Main函数中的setup类的属性，所以您必须将Main实例绑定到该函数。

window.onload = app.setup.bind(app);

onload事件没有触发 - JS

1 个答案: