本文据下址理得http://www.zhangxinxu.com/wordpress/?p=552

 

css3:(有兼容限制)

-webkit-transform:rotate(-90deg);-moz-transform:rotate(-90deg);

transform:rotate(-90deg);

 

ie滤镜:

filter:progid:DXImageTransform.Microsoft.BasicImage(rotation=3);

“rotation=3”,这里的参数可以是0,1,2,3,但没有4,5....这里的数值*π/2=选转的度数,也就是乘以90度。但是只能局限于90度的倍数,如果要突破这种局限,可以采用如下矩阵变换的方式得到旋转60度,ie8下要使用-ms-filter代替filter

filter:progid:DXImageTransform.Microsoft.Matrix(M11=0.5,M12=-0.866,M21=0.866,M22=0.5,SizingMethod='auto expand');

也就是如下公式,这里的rotation表示角度,如60,

filter:progid:DXImageTransform.Microsoft.Matrix(M11=cos(roation),M12=-sin(roation),M21=sin(roation),M22=cos(roation),SizingMethod='auto expand');

对比

css3旋转不会改变占位大小可能覆盖别的元素,ie滤镜会改变挤开别的元素

不考虑opera,<firfox2,就很容易实现旋转,否则就使用canvas实现:

  canvas是html元素,没有行为,但提供api给js绘图到一个画布;

ie下实现:

<!- -[if IE]><script type="text/javascript" src="http://www.zhangxinxu.com/style/js/excanvas.js"></script><![endif]- ->(这里为了防止注释冲突,双连线用空格隔开了,然后作者也推广了自己)

其中的链接是使ie大部分支持canvas的js插件  

jQuery的旋转插件(ie滤镜+其他浏览器使用canvas)(见附录)

使用方法:$("选择器").rotateLeft(); 与 $("选择器").rotateRight();但如果不做任何特别的处理的话,此插件只支持一次的图片旋转效果,因为分析插件可知,当运行一次canvas旋转后,canvas标签会将原来的图片标签代替掉,使得图片的连续旋转遇到麻烦,需要每次旋转后重新输入图片相关的HTML代码。

param.right.click(function(){
	if(!$("img#rotImg").length){
		param.box.html('<img id="rotImg" src="http://image.zhangxinxu.com/image/study/s/s512/mm1.jpg" />');
	}
	fun.right(); //执行向右旋转
	return false;
});

  

更强大的jq旋转插件如 jQueryRotate.js

 

附录:

jq旋转插件:

jQuery.fn.rotate = function(angle,whence) {
	var p = this.get(0);

	// 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.round(Math.cos(rotation) * 1000) / 1000;
	var sintheta = Math.round(Math.sin(rotation) * 1000) / 1000;
	//alert(costheta+","+sintheta);
 
	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);
}

jQuery.fn.rotateRight = function(angle) {
	this.rotate(angle==undefined?90:angle);
}

jQuery.fn.rotateLeft = function(angle) {
	this.rotate(angle==undefined?-90:-angle);
}