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如何用js實現(xiàn)div的背景顏色漸變？求解答

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2023-08-04 10:26

admin

這是薯稿我以前收藏的代碼，利用CSS+JS實現(xiàn)漸變，代碼如下：

<!doctype?html?public?'-//w3c//dtd?html?4.01//en'?''>

<html>

<head>

var?setGradient?數(shù)寬孝=?(function(){

//private?variables;

var?p_dCanvas?=?document.createElement('canvas');

var?p_useCanvas?=?!!(?typeof(p_dCanvas.getContext)?==?'function');

var?p_dCtx?=?p_useCanvas?p_dCanvas.getContext('2d'):null;

var?p_isIE?=?/*@cc_on!@*/false;

//test?if?toDataURL()?is?supported?by?Canvas?since?Safari?may?not?support?it

???try{???p_dCtx.canvas.toDataURL()?巧盯}catch(err){

??????????p_useCanvas?=?false?;

???};??

if(p_useCanvas){

????return?function?(dEl?,?sColor1?,?sColor2?,?bRepeatY?){

???if(typeof(dEl)?==?'string')?dEl?=?document.getElementById(dEl);

???if(!dEl)?return?false;

???var?nW?=?dEl.offsetWidth;

???var?nH?=?dEl.offsetHeight;

???p_dCanvas.width?=?nW;

???p_dCanvas.height?=?nH;

???var?dGradient;

???var?sRepeat;

???//?Create?gradients

???if(bRepeatY){

????dGradient?=?p_dCtx.createLinearGradient(0,0,nW,0);

????sRepeat?=?'repeat-y';

???}else{

????dGradient?=?p_dCtx.createLinearGradient(0,0,0,nH);

????sRepeat?=?'repeat-x';

???}?

???dGradient.addColorStop(0,sColor1);

???dGradient.addColorStop(1,sColor2);????

???p_dCtx.fillStyle?=?dGradient?;?

???p_dCtx.fillRect(0,0,nW,nH);

???var?sDataUrl?=?p_dCtx.canvas.toDataURL('image/png');

???with(dEl.style){

????backgroundRepeat?=?sRepeat;

????backgroundImage?=?'url('?+?sDataUrl?+?')';

????backgroundColor?=?sColor2;????

???};

????}

}else?if(p_isIE){

p_dCanvas?=?p_useCanvas?=?p_dCtx?=?null;?

return?function?(dEl?,?sColor1?,?sColor2?,?bRepeatY){

???if(typeof(dEl)?==?'string')?dEl?=?document.getElementById(dEl);

???if(!dEl)?return?false;

???dEl.style.zoom?=?1;

???var?sF?=?dEl.currentStyle.filter;

???dEl.style.filter?+=?'?'?+?['progid:DXImageTransform.Microsoft.gradient(?GradientType=',?+(!!bRepeatY?),',enabled=true,startColorstr=',sColor1,',?endColorstr=',sColor2,')'].join('');

};

}else{

p_dCanvas?=?p_useCanvas?=?p_dCtx?=?null;

return?function(dEl?,?sColor1?,?sColor2?){

???if(typeof(dEl)?==?'string')?dEl?=?document.getElementById(dEl);

???if(!dEl)?return?false;

???with(dEl.style){

?????backgroundColor?=?sColor2;?

???};

???//alert('your?browser?does?not?support?gradient?effet');

}

})();

</script>

<style>

body{font:0.75em/1.4?Arial;text-align:left;margin:20px;}

hr{clear:both;visibility:hidden;}

xmp{font:12px/12px?Courier?New;background:#fff;color:#666;?border:solid?1px?#ccc;}

div.example{?border:solid?1px?#555;margin:0?20px?20px?0;float:left;?display:inline;margin:1em;background:#fff;width:300px;padding:40px;color:#222;font:xx-small/1.2?Tahoma;text-align:justify;}

</style>

<body>

<div?id=example1?class=example>

Lorem?ipsum?dolor?sit?amet,?consectetuer?adipiscing?elit.?Aliquam?blandit?nunc?lobortis?diam?bibendum?semper.?Nunc?aliquam?aliquam?mi.?Maecenas?porttitor,?lorem?sed?mattis?ultrices,?lorem?risus?consequat?mi,?vitae?ullamcorper?leo?ipsum?in?tellus.?Pellentesque?arcu?est,?sollicitudin?sed,?ultricies?quis,?vestibulum?a,?neque.?Duis?massa?elit,?gravida?vel,?lacinia?eu,?pretium?eget,?ipsum.?Etiam?magna?urna,?ultrices?ut,?eu?</div>

<div?id=example2?class=example>

<div?id=example3?class=example>

<div?id=example4?class=example>

<div?id=example5?class=example>

<div?id=example6?class=example>

setGradient('example1','#4ddbbe','#d449cc',1);

setGradient('example2','#46ddbd','#d8b617',0);

setGradient('example3','#c81fc1','#bf445f',1);

setGradient('example4','#2285e5','#d769eb',0);

setGradient('example5','#8b4286','#eac87d',1);

setGradient('example6','black','white',0);

</script>