讓圖片旋轉任意角度及JQuery外掛程式使用介紹_jquery

引入下方的jquery.rotate.js文件，然後透過$("選擇器").rotate(角度);可以旋轉任意角度，
例如$("#rotate-image").rotate(45);把這句放在$(document).ready(function(){ });中
就是將id為rotate-image的圖片旋轉45度。

不過，貌似在Chrome中總是不顯示。
唉，找了兩個小時，才發現Chrome太坑爹了，沒辦法取得圖片的長寬。
解決方法是，把$("#rotate-image").rotate(45);放在
$(window).load(function(){ });中，因為在Chrome中圖片在執行$(document).ready(function(){ });中的語句時並沒有載入完圖片，坑爹啊。

另外可以更方便的透過呼叫$("選擇器").rotateRight()和$("選擇器").rotateLeft()來分別向右旋轉90度和向左旋轉90度。

jquery.rotate.js:

複製程式碼 程式碼如下:

程式碼如下:



程式碼如下:



程式碼如下:



程式碼如下：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 = pvas.oImage = pvas.oImage = pvas.oImage = pvas.oImage = pvas.oImage = pvas.oImage = pvas。 .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 context.translate(sintheta*canvas.oImage.height,0);
} else if (rotation context.translate(canvas.width,-costheta*canvas.oImage.height);
} else if (rotation 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();

} } context.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 ); }