快捷導(dǎo)航

js實(shí)現(xiàn)圖片旋轉(zhuǎn)的三種方法

更新時(shí)間：2014年04月10日 15:28:38 作者：

這篇文章主要介紹了js實(shí)現(xiàn)圖片旋轉(zhuǎn)的三種方法,需要的朋友可以參考下

1 使用jQueryRotate.js實(shí)現(xiàn)

示例代碼：

 
<!DOCTYPE html> 
<html> 
<head> 
<title></title> 
<style type="text/css"> 
#div1 { 
width: 800px; 
height: 600px; 
background-color: #ff0; 
position: absolute; 
} 
.imgRotate { 
width: 100px; 
height: 80px; 
position: absolute; 
top: 50%; 
left: 50%; 
margin: -40px 0 0 -50px; 
} 
</style> 
</head> 
<body> 
<div id="div1"> 
<img id="img1" class="imgRotate" src="http://www.baidu.com/img/logo-yy.gif" /> 
<input id="input2" type="button" value="btn2"></input> 
</div> 
</body> 
<script type="text/javascript" src="jquery.min.js"></script> 
<script type="text/javascript" src="jQueryRotate.js"></script> 
<script type="text/javascript"> 
var num = 0; 
$("#input2").click(function(){ 
num ++; 
$("#img1").rotate(90*num); 
}); 
</script> 
</html> 

測(cè)試結(jié)果：chrome下效果正常，旋轉(zhuǎn)后img對(duì)象仍為img對(duì)象；ie8下效果正常，但旋轉(zhuǎn)后img對(duì)象變?yōu)橄旅鎸?duì)象，由于對(duì)象變化，若旋轉(zhuǎn)后仍按原來方法獲取img對(duì)象，則會(huì)報(bào)js錯(cuò)誤。欲獲取image對(duì)象，可根據(jù)class獲取。如果圖像旋轉(zhuǎn)后，不進(jìn)行其它操作，則可用此方法。若進(jìn)行其它操作，如放大、縮小圖像，則此方法實(shí)現(xiàn)較復(fù)雜。

復(fù)制代碼代碼如下:

 
<span ...> 
<rvml:group class="rvml"...> 
<rvml:image class="rvml".../> 
</rvml:group> 
</span> 

2 使用Microsoft提供的Matrix對(duì)象

示例代碼：

復(fù)制代碼代碼如下:

 
<!DOCTYPE html> 
<html> 
<head> 
<title></title> 
<style type="text/css"> 
#div1 { 
width: 800px; 
height: 600px; 
background-color: #ff0; 
position: absolute; 
} 
.imgRotate { 
width: 100px; 
height: 100px; 
position: absolute; 
top: 50%; 
left: 50%; 
margin: -50px 0 0 -50px; 
} 
#imgRotate { 
width: 100px; 
height: 100px; 
position: absolute; 
top: 50%; 
left: 50%; 
margin: -50px 0 0 -50px; 
} 
</style> 
</head> 
<body> 
<div id="div1"> 
<img id="img1" class="imgRotate" src="http://www.baidu.com/img/logo-yy.gif" /> 
<input id="input1" type="button" value="btn1"></input> 
</div> 
</body> 
<script type="text/javascript" src="jquery.min.js"></script> 
<script type="text/javascript"> 
function rotate(id,angle,whence) { 
var p = document.getElementById(id); 

// we store the angle inside the image tag for persistence 
if (!whence) { 
p.angle = ((p.angle==undefined?0:p.angle) + angle) % 360; 
} else { 
p.angle = angle; 
} 

if (p.angle >= 0) { 
var rotation = Math.PI * p.angle / 180; 
} else { 
var rotation = Math.PI * (360+p.angle) / 180; 
} 
var costheta = Math.cos(rotation); 
var sintheta = Math.sin(rotation); 

if (document.all && !window.opera) { 
var canvas = document.createElement('img'); 

canvas.src = p.src; 
canvas.height = p.height; 
canvas.width = p.width; 

canvas.style.filter = "progid:DXImageTransform.Microsoft.Matrix(M11="+costheta+",M12="+(-sintheta)+",M21="+sintheta+",M22="+costheta+",SizingMethod='auto expand')"; 
} else { 
var canvas = document.createElement('canvas'); 
if (!p.oImage) { 
canvas.oImage = new Image(); 
canvas.oImage.src = p.src; 
} else { 
canvas.oImage = p.oImage; 
} 

canvas.style.width = canvas.width = Math.abs(costheta*canvas.oImage.width) + Math.abs(sintheta*canvas.oImage.height); 
canvas.style.height = canvas.height = Math.abs(costheta*canvas.oImage.height) + Math.abs(sintheta*canvas.oImage.width); 

var context = canvas.getContext('2d'); 
context.save(); 
if (rotation <= Math.PI/2) { 
context.translate(sintheta*canvas.oImage.height,0); 
} else if (rotation <= Math.PI) { 
context.translate(canvas.width,-costheta*canvas.oImage.height); 
} else if (rotation <= 1.5*Math.PI) { 
context.translate(-costheta*canvas.oImage.width,canvas.height); 
} else { 
context.translate(0,-sintheta*canvas.oImage.width); 
} 
context.rotate(rotation); 
context.drawImage(canvas.oImage, 0, 0, canvas.oImage.width, canvas.oImage.height); 
context.restore(); 
} 
canvas.id = p.id; 
canvas.angle = p.angle; 
p.parentNode.replaceChild(canvas, p); 
} 

function rotateRight(id,angle) { 
rotate(id,angle==undefined?90:angle); 
} 

function rotateLeft(id,angle) { 
rotate(id,angle==undefined?-90:-angle); 
} 
$("#input1").click(function(){ 
$("img.imgRotate").attr("id","imgRotate"); 
rotateLeft("imgRotate",90); 
$("#imgRotate").attr("top","50%"); 
$("#imgRotate").attr("left","50%"); 
$("#imgRotate").attr("margin","-50px 0 0 -50px"); 
}); 
</script> 
</html> 

測(cè)試結(jié)果：chrome下效果正常，但旋轉(zhuǎn)后img對(duì)象變?yōu)閏anvas對(duì)象；ie8下效果正常，旋轉(zhuǎn)后img對(duì)象仍為img對(duì)象。Matrix()參數(shù)較多，使用時(shí)需較多計(jì)算。

3 使用Microsoft提供的BasicImage對(duì)象

示例代碼：

復(fù)制代碼代碼如下:

 
<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Strict//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-strict.dtd"> 
<html xmlns="http://www.w3.org/1999/xhtml"> 
<head> 
<meta http-equiv="Content-Type" content="text/html; charset=UTF-8" /> 
</head> 
<body> 
<img id="image" src="http://www.baidu.com/img/logo-yy.gif" /> 
<input id="input2" type="button" value="btn2"></input> 
</body> 
<script type="text/javascript" src="jquery.min.js"></script> 

<script type="text/javascript"> 
var num = 0; 
$("#input2").click(function(){ 
num = (num + 1) % 4; 
document.getElementById('image').style.filter = 'progid:DXImageTransform.Microsoft.BasicImage(rotation='+num+')'; 
}); 
</script> 
</html> 

測(cè)試結(jié)果：chrome下不能旋轉(zhuǎn)；ie8下效果正常，旋轉(zhuǎn)后img對(duì)象仍為img對(duì)象。BasicImage()僅一個(gè)參數(shù)。

查看這三種方法的代碼會(huì)發(fā)現(xiàn)，本質(zhì)上是一種解決方案：chrome下使用canvas對(duì)象實(shí)現(xiàn)，ie8下使用VML或者M(jìn)atrix()或BasicImage()實(shí)現(xiàn)。本人近期改造一個(gè)組件：其中涉及到旋轉(zhuǎn)、放大圖片，由于jQueryRotate.js在ie8下會(huì)生成一個(gè)新的對(duì)象，導(dǎo)致放大圖片前選擇圖片時(shí)，需要進(jìn)行特殊處理。后決定對(duì)chrome、ie8分開處理，chrome下使用jQueryRotate實(shí)現(xiàn)，ie8下使用BasicImage()實(shí)現(xiàn)，保證了代碼的簡(jiǎn)潔性和可讀性。

您可能感興趣的文章: