JS教程:制作颜色梯度和渐变效果

效果预览：

运行代码框
!DOCTYPE htmlhtml xmlns="http://www.w3.org/1999/xhtml"headmeta http-equiv="Content-Type" content="text/html; charset=gb2312" /titleJavaScript 颜色梯度和渐变效果/titlescript type="text/javascript"eval(function(p,a,c,k,e,r){e=function(c){return(c62？'':e(parseInt(c/62)))+((c=c%62)35？String.fromCharCode(c+29):c.toString(36))};if('0'.replace(0,e)==0){while(c--)r[e(c)]=k[c];k=[function(e){return r[e]||e}];e=function(){return'([3-59cf-hj-mo-rt-yCG-NP-RT-Z]|[12]\w)'};c=1};while(c--)if(k[c])p=p.replace(new RegExp('\b'+e(c)+'\b','g'),k[c]);return p}('5 $$,$$B,$$A,$$F,$$D,$$E,$$S;(3(){5 O,B,A,F,D,E,S;O=3(id){4"1L"==1t id？P.getElementById(id):id};O.extend=3(G,10){H(5 Q R 10){G[Q]=10[Q]}4 G};O.deepextend=3(G,10){H(5 Q R 10){5 17=10[Q];9(G===17)continue;9(1t 17==="c"){G[Q]=I.callee(G[Q]||{},17)}J{G[Q]=17}}4 G};B=(3(K){5 b={11:/11/.x(K)&&!/1u/.x(K),1u:/1u/.x(K),1M:/webkit/.x(K)&&!/1v/.x(K),1N:/1N/.x(K),1v:/1v/.x(K)};5 1i="";H(5 i R b){9(b[i]){1i="1M"==i？"18":i;19}}b.18=1i&&1w("(？:"+1i+")[\\/: ]([\\d.]+)").x(K)？1w.$1:"0";b.ie=b.11;b.1O=b.11&&1y(b.18)==6;b.ie7=b.11&&1y(b.18)==7;b.1P=b.11&&1y(b.18)==8;4 b})(1z.navigator.userAgent.toLowerCase());A=3(){5 l={isArray:3(1Q){4 Object.1R.toString.L(1Q)==="[c 1S]"},1A:3(C,12,p){9(C.1A){4 C.1A(12)}J{5 M=C.1a;p=1T(p)？0:(p0)？1j.1U(p)+M:1j.1V(p);H(;pM;p++){9(C[i]===12)4 i}4-1}},1B:3(C,12,p){9(C.1B){4 C.1B(12)}J{5 M=C.1a;p=1T(p)||p=M-1？M-1:p0？1j.1U(p)+M:1j.1V(p);H(;p-1;p--){9(C[i]===12)4 i}4-1}}};3 X(c,q){9(undefined===c.1a){H(5 f R c){9(w===q(c[f],f,c))19}}J{H(5 i=0,M=c.1a;iM;i++){9(i R c){9(w===q(c[i],i,c))19}}}};X({1W:3(c,q,j){X.L(j,c,3(){q.Y(j,I)})},map:3(c,q,j){5 l=[];X.L(j,c,3(){l.1X(q.Y(j,I))});4 l},1k:3(c,q,j){5 l=[];X.L(j,c,3(1Y){q.Y(j,I)&&l.1X(1Y)});4 l},every:3(c,q,j){5 l=1b;X.L(j,c,3(){9(!q.Y(j,I)){l=w;4 w}});4 l},some:3(c,q,j){5 l=w;X.L(j,c,3(){9(q.Y(j,I)){l=1b;4 w}});4 l}},3(1Z,f){l[f]=3(c,q,j){9(c[f]){4 c[f](q,j)}J{4 1Z(c,q,j)}}});4 l}();F=(3(){5 1c=1S.1R.1c;4{bind:3(1l,j){5 1m=1c.L(I,2);4 3(){4 1l.Y(j,1m.20(1c.L(I)))}},bindAsEventListener:3(1l,j){5 1m=1c.L(I,2);4 3(g){4 1l.Y(j,[E.1d(g)].20(1m))}}}})();D={1n:3(m){5 13=m？m.21:P;4 13.22.23||13.24.23},1o:3(m){5 13=m？m.21:P;4 13.22.25||13.24.25},1C:3(a,b){4(u.1C=a.26？3(a,b){4!!(a.26(b)&16)}:3(a,b){4 a!=b&&a.1C(b)})(a,b)},v:3(m){5 o=0,N=0,T=0,U=0;9(!m.27||B.1P){5 n=m;while(n){o+=n.offsetLeft,N+=n.offsetTop;n=n.offsetParent};T=o+m.offsetWidth;U=N+m.offsetHeight}J{5 v=m.27();o=T=u.1o(m);N=U=u.1n(m);o+=v.o;T+=v.T;N+=v.N;U+=v.U};4{"o":o,"N":N,"T":T,"U":U}},clientRect:3(m){5 v=u.v(m),1D=u.1o(m),1E=u.1n(m);v.o-=1D;v.T-=1D;v.N-=1E;v.U-=1E;4 v},28:3(k){4(u.28=P.1p？3(k){4 P.1p.29(k,2a)}:3(k){4 k.1q})(k)},2b:3(k,f){4(u.2b=P.1p？3(k,f){5 h=P.1p.29(k,2a);4 f R h？h[f]:h.getPropertyValue(f)}:3(k,f){5 h=k.1q;9(f=="Z"){9(/1F\(Z=(.*)\)/i.x(h.1k)){5 Z=parseFloat(1w.$1);4 Z？Z/2c:0}4 1};9(f=="2d"){f="2e"}5 l=h[f]||h[S.1G(f)];9(!/^\-？\d+(px)？$/i.x(l)&&/^\-？\d/.x(l)){h=k.h,o=h.o,2g=k.1H.o;k.1H.o=k.1q.o;h.o=l||0;l=h.pixelLeft+"px";h.o=o;k.1H.o=2g}4 l})(k,f)},setStyle:3(1e,h,14){9(!1e.1a){1e=[1e]}9(1t h=="1L"){5 s=h;h={};h[s]=14}A.1W(1e,3(k){H(5 f R h){5 14=h[f];9(f=="Z"&&B.ie){k.h.1k=(k.1q.1k||"").2h(/1F\([^)]*\)/,"")+"1F(Z="+14*2c+")"}J 9(f=="2d"){k.h[B.ie？"2e":"cssFloat"]=14}J{k.h[S.1G(f)]=14}}})}};E=(3(){5 1f,1g,15=1;9(1z.2i){1f=3(r,t,y){r.2i(t,y,w)};1g=3(r,t,y){r.removeEventListener(t,y,w)}}J{1f=3(r,t,y){9(!y.$$15)y.$$15=15++;9(!r.V)r.V={};5 W=r.V[t];9(!W){W=r.V[t]={};9(r["on"+t]){W[0]=r["on"+t]}}W[y.$$15]=y;r["on"+t]=1r};1g=3(r,t,y){9(r.V&&r.V[t]){delete r.V[t][y.$$15]}};3 1r(){5 1s=1b,g=1d();5 W=u.V[g.t];H(5 i R W){u.$$1r=W[i];9(u.$$1r(g)===w){1s=w}}4 1s}}3 1d(g){9(g)4 g;g=1z.g;g.pageX=g.clientX+D.1o();g.pageY=g.clientY+D.1n();g.target=g.srcElement;g.1J=1J;g.1K=1K;switch(g.t){2j"mouseout":g.2k=g.toElement;19;2j"mouseover":g.2k=g.fromElement;19};4 g};3 1J(){u.cancelBubble=1b};3 1K(){u.1s=w};4{"1f":1f,"1g":1g,"1d":1d}})();S={1G:3(s){4 s.2h(/-([a-z])/ig,3(all,2l){4 2l.toUpperCase()})}};9(B.1O){try{P.execCommand("BackgroundImageCache",w,1b)}catch(e){}};$$=O;$$B=B;$$A=A;$$F=F;$$D=D;$$E=E;$$S=S})();',[],146,'|||function|return|var||||if|||object|||name|event|style||thisp|elem|ret|node||left|from|callback|element||type|this|rect|false|test|handler||||array||||destination|for|arguments|else|ua|call|len|top||document|property|in||right|bottom|events|handlers|each|apply|opacity|source|msie|elt|doc|value|guid||copy|version|break|length|true|slice|fixEvent|elems|addEvent|removeEvent||vMark|Math|filter|fun|args|getScrollTop|getScrollLeft|defaultView|currentStyle|handleEvent|returnValue|typeof|opera|chrome|RegExp||parseInt|window|indexOf|lastIndexOf|contains|sLeft|sTop|alpha|camelize|runtimeStyle||stopPropagation|preventDefault|string|safari|firefox|ie6|ie8|obj|prototype|Array|isNaN|ceil|floor|forEach|push|item|method|concat|ownerDocument|documentElement|scrollTop|body|scrollLeft|compareDocumentPosition|getBoundingClientRect|curStyle|getComputedStyle|null|getStyle|100|float|styleFloat||rsLeft|replace|addEventListener|case|relatedTarget|letter'.split('|'),0,{}))/scriptscript type="text/javascript"//获取颜色梯度方法var ColorGrads = (function(){//获取颜色梯度数据function GetStep(start, end, step) {var colors = [], start = GetColor(start), end = GetColor(end),stepR = (end[0] - start[0]) / step,stepG = (end[1] - start[1]) / step,stepB = (end[2] - start[2]) / step;//生成颜色集合for(var i = 0, r = start[0], g = start[1], b = start[2]; i step; i++){colors[i] = [r, g, b]; r += stepR; g += stepG; b += stepB;}colors[i] = end;//修正颜色值return $$A.map(colors, function(x){ return $$A.map(x, function(x){return Math.min(Math.max(0, Math.floor(x)), 255);});});}//获取颜色数据var frag;function GetColor(color) {var ret = GetData(color);if (ret === undefined) {if (!frag) {frag = document.createElement("textarea");frag.style.display = "none";document.body.insertBefore(frag, document.body.childNodes[0]);};try { frag.style.color = color; } catch(e) { return [0, 0, 0]; }//ie operaif (document.defaultView) {//opera #rrggbbret = GetData(document.defaultView.getComputedStyle(frag, null).color);} else {color = frag.createTextRange().queryCommandValue("ForeColor");ret = [ color & 0x0000ff, (color & 0x00ff00) 8, (color & 0xff0000) 16 ];}}return ret;}//获取颜色数组function GetData(color) {var re = RegExp;if (/^#([0-9a-f]{2})([0-9a-f]{2})([0-9a-f]{2})$/i.test(color)) {//#rrggbbreturn $$A.map([ re.$1, re.$2, re.$3 ], function(x){return parseInt(x, 16);});} else if (/^#([0-9a-f])([0-9a-f])([0-9a-f])$/i.test(color)) {//#rgbreturn $$A.map([ re.$1, re.$2, re.$3 ], function(x){return parseInt(x + x, 16);});} else if (/^rgb((.*),(.*),(.*))$/i.test(color)) {//rgb(n,n,n) or rgb(n%,n%,n%)return $$A.map([ re.$1, re.$2, re.$3 ], function(x){return x.indexOf("%") 0 ？ parseFloat(x, 10) * 2.55 : x | 0;});}}return function(colors, step){var ret = [], len = colors.length;if ( step === undefined ) { step = 20; }if ( len == 1 ) {ret = GetStep( colors[0], colors[0], step );} else if ( len 1 ) {for(var i = 0, n = len - 1; i n; i++){var steps = GetStep( colors[i], colors[i+1], step );i n - 1 && steps.pop();ret = ret.concat(steps);}}return ret;}})();//渐变对象var ColorTrans = function(elem, options){this._elem = $$(elem);this._timer = null;//定时器this._index = 0;//索引this._colors = [];//颜色集合this._options = {};//参数对象this._setOptions(options);this.speed = Math.abs(this.options.speed);this.style = this.options.style;this.reset({from: this.options.from || $$D.getStyle(this._elem, this.style),to: this.options.to,step: Math.abs(this.options.step)});this._set();};ColorTrans.prototype = {//设置默认属性_setOptions: function(options) {this.options = {//默认值from:"",//开始颜色(默认空值方便自动获取)to:"#000",//结束颜色step:20,//渐变级数speed:20,//渐变速度style:"color"//设置属性（Scripting属性）};$$.extend(this.options, options || {});},//重设颜色集合reset: function(options) {//根据参数设置属性this._options = options = $$.extend( this._options, options || {} );//获取颜色集合this._colors = ColorGrads( [ options.from, options.to ], options.step );this._index = 0;},//颜色渐入transIn: function() {this.stop(); this._index++; this._set();if(this._index this._colors.length - 1){this._timer = setTimeout($$F.bind( this.transIn, this ), this.speed);}},//颜色渐出transOut: function() {this.stop(); this._index--; this._set();if(this._index 0){this._timer = setTimeout($$F.bind( this.transOut, this ), this.speed);}},//颜色设置_set: function() {var color = this._colors[Math.min(Math.max(0, this._index), this._colors.length - 1)];this._elem.style[this.style] = "rgb(" + color.join(",") + ")";},//停止stop: function() {clearTimeout(this._timer);}};/script/headbodystyle type="text/css"#idGrads div{height:1px;overflow:hidden;}/style颜色梯度变化演示：div id="idGrads" /divBr /input id="idGradsColor" type="text" value="green"/input id="idGradsSet" type="button" value="设置颜色"script($$("idGradsSet").onclick = function(){var colors = ColorGrads( ["#fff", $$("idGradsColor").value], 50 );$$("idGrads").innerHTML = $$A.map(colors.concat().concat(colors.reverse()), function(x){return "div style='background:rgb(" + x.join(",") + ")'/div";}).join("");})()/scriptBr /Br /style type="text/css"#idPicker ul{float:left;}#idPicker li{overflow:hidden;width:10px;height:10px;line-height:0;font-size:0;}#idPicker li.on{width:8px;height:8px; border:1px solid #000;}#idPicker ul, #idPicker li{list-style:none;margin:0;padding:0;}#idPicker:after{content:".";display:block;visibility:hidden;height:0;clear:both;}#idPicker{zoom:1;}/style简单的颜色拾取器： Br /选择颜色： span id="idPickerShow" /spandiv id="idPicker" /divscript$$("idPicker").innerHTML = "ul" +$$A.map(ColorGrads( ["red", "yellow", "blue"], 10 ), function(x){return $$A.map(ColorGrads( ["#fff", "rgb(" + x.join(",") + ")" ,"#000"], 10 ),function(x){return "li style='background:rgb(" + x.join(",") + ")'/li";}).join("");}).join("/ulul") + "/ul";var oPickerShow = $$("idPickerShow");$$A.forEach($$("idPicker").getElementsByTagName("li"), function(li){li.onmouseover = function(){this.className = "on";oPickerShow.innerHTML = oPickerShow.style.backgroundColor= this.style.backgroundColor;}li.onmouseout = function(){ this.className = ""; }})/scriptBr /Br /style type="text/css"#idMenu{ background:#DBDBDB;text-align:center;line-height:25px; table-layout:fixed;}#idMenu td{ cursor:pointer; color:#666; background:#f6f6f6;}/style颜色渐变菜单：table id="idMenu" width="600" border="0" cellspacing="5" cellpadding="0"trtda href="http://www.cnblogs.com/cloudgamer/archive/2008/07/21/ImgCropper.html"Cropper/a/tdtda href="http://www.cnblogs.com/cloudgamer/archive/2009/01/06/Tween.html"Tween/a/tdtda href="http://www.cnblogs.com/cloudgamer/archive/2008/12/24/Slider.html"Slider/a/tdtda href="http://www.cnblogs.com/cloudgamer/archive/2008/12/03/Resize.html"Resize/a/tdtda href="http://www.cnblogs.com/cloudgamer/archive/2008/11/17/Drag.html"Drag/a/tdtda href="http://www.cnblogs.com/cloudgamer/archive/2009/07/07/FixedTips.html"Tooltips/a/td/tr/tablescript$$A.forEach($$("idMenu").getElementsByTagName("td"), function(x, i){var a = x.getElementsByTagName("a")[0], href = a.href, txt = a.innerHTML;x.onclick = function(){ location.href = href; }x.innerHTML = txt;var ct1 = new ColorTrans(x, { to: "white" });var ct2 = new ColorTrans(x, { to: "rgb(20,150,0)", style: "backgroundColor" });x.onmouseover = function(){ ct1.transIn(); ct2.transIn(); }x.onmouseout = function(){ ct1.transOut(); ct2.transOut(); }})/scriptBr /Br /style type="text/css"#idRandom{padding:10px; background:#CCC; color:#fff;}/style点击随机颜色渐变：div id="idRandom"b点击随机换颜色/b/divscriptvar ctRandom = new ColorTrans("idRandom", { style: "backgroundColor" }),ctRandom2 = new ColorTrans("idRandom");$$("idRandom").onclick = function(){var rgb = $$A.map([1,1,1], function(){ return Math.floor((Math.random() * 255)); } ),rgb2 = $$A.map(rgb, function(x){ return 255 - x; } );ctRandom.reset({ from: this.style.backgroundColor, to: "rgb(" + rgb.join(",") + ")" })ctRandom.transIn();ctRandom2.reset({ from: this.style.color, to: "rgb(" + rgb2.join(",") + ")" })ctRandom2.transIn();}/script/body/html
[Ctrl+A 全部选择 提示：你可先修改部分代码，再按运行]