如何通过JavaScript更改CSS渐变？

Question

我有一个div,应用了以下渐变:

/* Mozilla Firefox */ 
background-image: -moz-linear-gradient(top, #2E2E28 0%, #4D4C48 100%);
/* Opera */ 
background-image: -o-linear-gradient(top, #2E2E28 0%, #4D4C48 100%);
/* Webkit (Safari/Chrome 10) */ 
background-image: -webkit-gradient(linear, left top, left bottom, color-stop(0, #2E2E28), color-stop(1, #4D4C48));
/* Webkit (Chrome 11+) */ 
background-image: -webkit-linear-gradient(top, #2E2E28 0%, #4D4C48 100%);
/* IE10+ */
background: -ms-linear-gradient(top,  #2E2E28 0%,#4D4C48 100%);
/* W3C */
background: linear-gradient(top,  #2E2E28 0%,#4D4C48 100%);

我怎么能将"#2E2E28"更改为另一个号码,但仍然避免跨浏览器的噩梦？

Answer 1

使用jQuery它将是:

$('.gradient').css({'background-image': 'linear-gradient(to top,  #2E2E28 0%, #4D4C48 100%)'});

野生动物园:

$('.gradient').css({'background-image': '-webkit-linear-gradient(top,  #2E2E28 0%, #4D4C48 100%)'});

请参阅此处以获取实时示例.

似乎跨浏览器工作.

编辑:

我做了一个小插件,可以帮助你使用不同的颜色:

;(function($) {
    var isSafari = /Safari/.test(navigator.userAgent) && /Apple Computer/.test(navigator.vendor);

    var methods = {
        init: function (settings) {

            settings = $.extend( {
              'colors'         : ['red', 'blue'],
              'direction'      : 'top'
            }, settings);

            return this.each(function(){
                if($.isArray(settings.colors) && settings.colors.length >= 2) {
                    $(this).css({ 
                        'background':
                        methods.gradientToString(settings.colors, settings.direction)
                    });
                } else {
                    $.error('Please pass an array');
                }

            });

        },
        gradientToString: function (colors, direction) {

            var nbColors = colors.length;

            //If no percent, we need to calculate them
            if(colors[0].percent === undefined) {

                //Passed only colors as an array we make it an object
                if(colors[0].color === undefined) {
                    var tmp = [];
                    for(i=0; i < nbColors; i++)
                        tmp.push({'color':colors[i]});

                    colors = tmp;
                }

                var p = 0,
                    percent = 100 / (nbColors - 1);

                //calculate percent
                for(i=0; i< nbColors; i++) {
                    p = i === 0 ? p : (i == nbColors-1 ? 100 : p + percent);
                    colors[i].percent = p;
                }
            }

            var to = isSafari ? '' : 'to';

            //build the string
            var gradientString = isSafari ? '-webkit-linear-gradient(' : 'linear-gradient(';

           gradientString += to +' '+ direction;

            for(i=0; i < nbColors; i++)
               gradientString += ', '+ colors[i].color + ' ' + colors[i].percent + '%';

            gradientString += ')';
            return gradientString;

        }

    };

    $.fn.gradientGenerator = function () {
        return methods.init.apply( this, arguments );
    };
})(jQuery);

像这样使用它,例如:

$('.gradient').gradientGenerator({
    colors : ['#2E2E28', '#4D4C48']
});

$('.change-color').on('click', function(e) {

    e.preventDefault();
    $('.gradient').gradientGenerator({
        colors : [{color:'#4D4C48',percent:0}, {color:'#282827', percent:30}, {color:'#2E2E28', percent: 100}],
        direction : 'left'
    });

});

看到它在这里工作.

Answer 2

以下函数将两种颜色作为参数并返回样式字符串,如您所指定的那样,并使用给定颜色替换相应的子字符串.

你可以在这里看到这个.

var makeGradientStyle = function(){
    var gradientString = '\
        /* Mozilla Firefox */ \
background-image: -moz-linear-gradient(top, {colour1} 0%, {colour2} 100%);\
        /* Opera */ \
        background-image: -o-linear-gradient(top, {colour1} 0%, {colour2} 100%);\
        /* Webkit (Safari/Chrome 10) */ \
        background-image: -webkit-gradient(linear, left top, left bottom, color-stop(0, {colour1}), color-stop(1, {colour2}));\
        /* Webkit (Chrome 11+) */ \
        background-image: -webkit-linear-gradient(top, {colour1} 0%, {colour2} 100%);\
        /* IE10+ */\
        background: -ms-linear-gradient(top,  {colour1} 0%,{colour2} 100%);\
        /* W3C */\
        background: linear-gradient(top,  {colour1} 0%,{colour2} 100%);\
    ';

    return function(colour1, colour2){
        return gradientString.replace(/\{colour1\}/g, colour1).replace(/\{colour2\}/g, colour2)
    }
}();

然后您可以按如下方式申请.缺点在于你要替换整个样式字符串,但你可以用它来代替

var p = document.getElementById('p');

p.setAttribute('style', p.getAttribute('style') + '; ' + makeGradientStyle('#ff0000', '#0000ff'));