jquery Go-top插件

jq-goTop

(function($){

        $.GoToTop = {
                defaults: {
                        autoShow : true,
                        timeEffect : 500,
                        effectScroll : 'linear',
                        appearMethod : 'slide'
                },
                
                init:function(options){
                        opts = $.extend({}, $.GoToTop.defaults, options),
                        $.GoToTop._constructLink();

                        if(opts.autoShow)
                        $(window).scroll(function(){
                                if($(this).scrollTop() != 0) {
                                        switch (opts.appearMethod) {
                                                case 'fade' : divBack.fadeIn('fast'); break;
                                                case 'slide' : divBack.slideDown('fast'); break;
                                                default : divBack.show();        
                                        }
                                }
                                else {
                                        switch (opts.appearMethod) {
                                                case 'fade' : divBack.fadeOut('fast'); break;
                                                case 'slide' : divBack.slideUp('fast'); break;
                                                default : divBack.hide();        
                                        }
                                }
                        });
                        
                        $('#GoToTop').click(function(e) {
                                e.preventDefault();
                                $('body,html').animate({scrollTop:0},opts.timeEffect,opts.effectScroll);
                        });
                },

                _constructLink:function() {
                        divBack = $('<a />',{
                                id : 'GoToTop',
                                href : '#body',
                                style : 'float: left; display: none; position: fixed; bottom: 40px; right: 0px; z-index: 90000; height: 60px; width: 60px; background-image: url("images/GoToTop.png"); background-repeat: no-repeat;'
                        }).prependTo('body');
                        if(!opts.autoShow) divBack.show();
                }
        
        };

        GoToTop = function(options) {
                $.GoToTop.init(options);
        };
})(jQuery);