我正在尝试动态地改变div-container的网格大小，通过使用JavaScript的范围滑块。
但是一旦mouseup-event处理程序触发，range slider的值就不会应用到div-container上。为什么范围滑块的值不适用于潜水容器?
我错过了什么?需要帮助吗?
"use strict";
const divContainer = document.querySelector(".container");
const input = document.querySelector("input");
const outputs = document.querySelectorAll("output");
let slider = document.getElementById("gridSize");
const body = document.querySelector("body");
document.body.ondragstart = () => { return false };
function createGrid(col, rows) {
for (let i = 0; i < (col * rows); i++) {
const div = document.createElement("div");
divContainer.style.gridTemplateColumns = `repeat(${col}, 1fr)`;
divContainer.style.gridTemplateRows = `repeat(${rows}, 1fr)`;
divContainer.appendChild(div).classList.add("box");
}
}
createGrid(50,50);
input.addEventListener("input", () => {
for (let output of outputs) {
output.innerText = input.value;
}
})
function modifyGridSize() {
let boxes = divContainer.querySelectorAll(".box");
boxes.forEach(box => box.remove());
createGrid(slider.value);
}
slider.addEventListener("mouseup", modifyGridSize);*,
*::before,
*::after {
margin: 0;
padding: 0;
-webkit-box-sizing: border-box;
box-sizing: border-box;
}
html {
font-size: 16px;
}
body {
background: linear-gradient(to bottom, #1488CC, #2B32B2);
color: #FFF;
line-height: 1.5;
height: 100vh;
}
#wrapper {
display: grid;
grid-template-areas: "buttons container";
grid-auto-columns: 50% 50%;
}
.container {
width: 510px;
height: 510px;
display: grid;
background-color: #FFF;
box-shadow: 0 0 10px;
}
.box {
border: .5px solid #808080;
}
.buttons {
display: flex;
flex-direction: column;
justify-content: center;
margin: 0 auto;
gap: 10px;
}
.btn {
width: 200px;
height: 50px;
font-family : inherit;
font-size: 2rem;
font-weight: bold;
color: #000;
}
.btn:hover {
box-shadow: 0 0 10px;
}
.btn:active {
box-shadow: inset 0 0 8px;
}
.blackBtn {
background: #000;
color: #4C4C4C;
}
.greyBtn {
background: linear-gradient(to right, #BDC3C7, #2C3E50);
}
.rainbowBtn {
background: linear-gradient(to right, orange , yellow, green, cyan, blue, violet);
}
.eraseBtn {
background: #FFF;
}
.clearCanvasBtn {
background: #FF0000;
}
.shake {
animation: shake .5s linear 1;
}
@keyframes shake {
10%,
90% {
transform: translate3d(-1px, 0, 0);
}
20%,
80% {
transform: translate3d(2px, 0, 0);
}
30%,
50%,
70% {
transform: translate3d(-4px, 0, 0);
}
40%,
60% {
transform: translate3d(4px, 0, 0);
}
}
#wrapper label {
font-size: 2rem;
}
.gridDimension {
font-size: 1.5rem;
text-align: center;
}
input[type="range"] {
margin-bottom: 40px;
}<!DOCTYPE html>
<html lang="en">
<head>
<meta charset="UTF-8">
<meta http-equiv="X-UA-Compatible" content="IE=edge">
<meta name="viewport" content="width=device-width, initial-scale=1.0, shrink-to-fit=no">
<title>Etch-A-Sketch</title>
<link rel="stylesheet" type="text/css" href="src/css/etchAsketch.css">
</head>
<body>
<main id="wrapper">
<div class="buttons">
<label for="gridSize">Select Grid Size:</label>
<div class="gridDimension"><output>50</output> x <output>50</output></div>
<input id="gridSize" type="range" name="gridSize" value="50" step="1" min="1" max="100">
</div>
<div class="container"></div>
</main>
<script src="etchAsketch.js"></script>
</body>
</html>createGrid接受两个参数，col和rows。您只传递了一个参数(col)。
这会导致你的for循环(for (let i = 0; i < (col * rows); i++))永远不会执行，因为这个语句:i < (col * rows)总是返回false。
这是因为col * undefined返回undefined，因此导致数字比较返回false。
使用:
createGrid(slider.value, slider.value);
"use strict";
const divContainer = document.querySelector(".container");
const input = document.querySelector("input");
const outputs = document.querySelectorAll("output");
let slider = document.getElementById("gridSize");
const body = document.querySelector("body");
document.body.ondragstart = () => { return false };
function createGrid(col, rows) {
for (let i = 0; i < (col * rows); i++) {
const div = document.createElement("div");
divContainer.style.gridTemplateColumns = `repeat(${col}, 1fr)`;
divContainer.style.gridTemplateRows = `repeat(${rows}, 1fr)`;
divContainer.appendChild(div).classList.add("box");
}
}
createGrid(50,50);
input.addEventListener("input", () => {
for (let output of outputs) {
output.innerText = input.value;
}
})
function modifyGridSize() {
let boxes = divContainer.querySelectorAll(".box");
boxes.forEach(box => box.remove());
createGrid(slider.value, slider.value);
}
slider.addEventListener("mouseup", modifyGridSize);*,
*::before,
*::after {
margin: 0;
padding: 0;
-webkit-box-sizing: border-box;
box-sizing: border-box;
}
html {
font-size: 16px;
}
body {
background: linear-gradient(to bottom, #1488CC, #2B32B2);
color: #FFF;
line-height: 1.5;
height: 100vh;
}
#wrapper {
display: grid;
grid-template-areas: "buttons container";
grid-auto-columns: 50% 50%;
}
.container {
width: 510px;
height: 510px;
display: grid;
background-color: #FFF;
box-shadow: 0 0 10px;
}
.box {
border: .5px solid #808080;
}
.buttons {
display: flex;
flex-direction: column;
justify-content: center;
margin: 0 auto;
gap: 10px;
}
.btn {
width: 200px;
height: 50px;
font-family : inherit;
font-size: 2rem;
font-weight: bold;
color: #000;
}
.btn:hover {
box-shadow: 0 0 10px;
}
.btn:active {
box-shadow: inset 0 0 8px;
}
.blackBtn {
background: #000;
color: #4C4C4C;
}
.greyBtn {
background: linear-gradient(to right, #BDC3C7, #2C3E50);
}
.rainbowBtn {
background: linear-gradient(to right, orange , yellow, green, cyan, blue, violet);
}
.eraseBtn {
background: #FFF;
}
.clearCanvasBtn {
background: #FF0000;
}
.shake {
animation: shake .5s linear 1;
}
@keyframes shake {
10%,
90% {
transform: translate3d(-1px, 0, 0);
}
20%,
80% {
transform: translate3d(2px, 0, 0);
}
30%,
50%,
70% {
transform: translate3d(-4px, 0, 0);
}
40%,
60% {
transform: translate3d(4px, 0, 0);
}
}
#wrapper label {
font-size: 2rem;
}
.gridDimension {
font-size: 1.5rem;
text-align: center;
}
input[type="range"] {
margin-bottom: 40px;
}<!DOCTYPE html>
<html lang="en">
<head>
<meta charset="UTF-8">
<meta http-equiv="X-UA-Compatible" content="IE=edge">
<meta name="viewport" content="width=device-width, initial-scale=1.0, shrink-to-fit=no">
<title>Etch-A-Sketch</title>
<link rel="stylesheet" type="text/css" href="src/css/etchAsketch.css">
</head>
<body>
<main id="wrapper">
<div class="buttons">
<label for="gridSize">Select Grid Size:</label>
<div class="gridDimension"><output>50</output> x <output>50</output></div>
<input id="gridSize" type="range" name="gridSize" value="50" step="1" min="1" max="100">
</div>
<div class="container"></div>
</main>
<script src="etchAsketch.js"></script>
</body>
</html>