JavaScript canvas实现九宫格切图效果
时间：2022-10-05 11:21:20 | 栏目：JavaScript代码 | 点击：次
本文实例为大家分享了canvas实现九宫格切图效果的具体代码，供大家参考，具体内容如下
首先页面展示
直接上代码
<!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>Document</title>
<style>
body {
text-align: center;
}
canvas {
border: 1px solid;
}
.newcanvas {
width: 316px;
height: 316px;
margin: auto;
}
.newpohoto,
.download {
width: 300px;
height: 40px;
line-height: 40px;
margin: auto;
background-color: cornflowerblue;
border-radius: 5px;
cursor: pointer;
margin: 10px auto;
color: white;
}
</style>
</head>
<body>
<h3>使用canvas实现九宫格切图的效果</h3>
<div class="mycanvas">
<canvas width="300" height="300" id="mycnavas"></canvas>
</div>
<div class="newpohoto">
开始切图
</div>
<div class="newcanvas">
<canvas width="100" height="100" id="img1"></canvas>
<canvas width="100" height="100" id="img2"></canvas>
<canvas width="100" height="100" id="img3"></canvas>
<canvas width="100" height="100" id="img4"></canvas>
<canvas width="100" height="100" id="img5"></canvas>
<canvas width="100" height="100" id="img6"></canvas>
<canvas width="100" height="100" id="img7"></canvas>
<canvas width="100" height="100" id="img8"></canvas>
<canvas width="100" height="100" id="img9"></canvas>
</div>
<div class="download">
下载图片
</div>
<script>
var canvas = document.getElementById("mycnavas"); //现将图片放上去
var cxt = mycnavas.getContext("2d");
var img = new Image();
img.src = "../img/img10.jpg";
window.onload = function() {
cxt.drawImage(img, 0, 0, 400, 300); //画好图片的位置
}
var arr = []; //将切的图片存到数组里面
document.getElementsByClassName("newpohoto")[0].onclick = function() {
var q = 1;
for (var i = 0; i < 3; i++) {
for (var j = 0; j < 3; j++) {
var data = cxt.getImageData(j * 100, i * 100, 400, 100); //类似于“复制”功能
var img = document.getElementById("img" + q)
var newcxt = img.getContext("2d");
newcxt.putImageData(data, 0, 0); //类似“粘贴”功能
arr.push(console.log(img.toDataURL(q + ".png"))) //toDataURL()方法的两个参数：DataURL(type, encoderOptions) type指定转换为base64编码后图片的格式，如：image/png、image/jpeg、image/webp等等，默认为image/png格式；
q++;
console.log(arr)
}
}
}
//下载切的图片
var arr = [];
document.getElementsByClassName('download')[0].onclick = function() {
for (var i = 0; i < 9; i++) {
var a = document.createElement('a');
a.download = 'img' + (i + 1);
a.href = arr[i];
document.body.appendChild(a);
a.click();
}
}
</script>
</body>
</html>