标签：ota nod doctype ges context get var lan onload
test.html
<!DOCTYPE html>
<html lang="en">
<head>
<meta charset="UTF-8">
<title>图片360度旋转</title>
<style>
input {
font-size:18px;
padding:5px 20px 5px 20px;
font-weight:bold;
color:white;
background-color:#c5464a;
cursor:pointer;
border:none;
outline:none;
border-radius:7px 7px 7px 7px;
}
</style>
<script type="text/javascript" src="test.js"></script>
</head>
<body>
<input type="button" value="←">
<input type="button" value="→">
<div id="mydiv">
<img src="img3.jpg" id="img">
</div>
</body>
</html>
test.js
window.onload = function() {
var inputval = document.getElementsByTagName(‘input‘);
var imgval = document.getElementById(‘img‘);
var yimg = new Image();
var iNow = 0;
yimg.onload = function() {
draw(imgval);
}
yimg.src = imgval.src;
function draw(obj) {
var c = document.createElement(‘canvas‘);
var cxt = c.getContext(‘2d‘);
c.width = obj.width;
c.height = obj.height;
obj.parentNode.replaceChild(c, obj);
cxt.drawImage(obj, 0, 0);
inputval[1].onclick = function() {
if (iNow == 3) {
iNow = 0;
} else {
iNow++;
}
toChange();
};
inputval[0].onclick = function() {
if (iNow == 0) {
iNow = 3;
} else {
iNow--;
}
toChange();
};
function toChange() {
switch (iNow) {
case 0:
c.width = obj.width;
c.height = obj.height;
cxt.rotate(0 * Math.PI / 180);
cxt.drawImage(obj, 0, 0);
break;
case 1:
c.width = obj.height;
c.height = obj.width;
cxt.rotate(90 * Math.PI / 180);
cxt.drawImage(obj, 0, -obj.height);
break;
case 2:
c.width = obj.width;
c.height = obj.height;
cxt.rotate(180 * Math.PI / 180);
cxt.drawImage(obj, -obj.width, -obj.height);
break;
case 3:
c.width = obj.height;
c.height = obj.width;
cxt.rotate(270 * Math.PI / 180);
cxt.drawImage(obj, -obj.width, 0);
break;
case 4:
c.width = obj.width;
c.height = obj.height;
cxt.rotate(360 * Math.PI / 180);
cxt.drawImage(obj, obj.width, obj.height);
break;
}
}
}
}
图片：
效果：
2017-09-08 23:03:47
标签：ota nod doctype ges context get var lan onload
原文地址：http://www.cnblogs.com/guangzhou11/p/7496758.html
