$.fn.longPress = function(fn) {

                var timeout = undefined;

                var $this = this;

                for(var i = 0;i<$this.length;i++){

                    $this[i].addEventListener('touchstart', function(e) {

                        e.preventDefault();

                        timeout = setTimeout(fn, 800);

                        }, false);

                    $this[i].addEventListener('mousedown', function(e) {

                        e.preventDefault();

                        timeout = setTimeout(fn, 800);

                    }, false);

                    $this[i].addEventListener('touchend', function(e) {

                        e.preventDefault();

                        clearTimeout(timeout);

                    }, false);

                    $this[i].addEventListener('mouseup', function(e) {

                        e.preventDefault();

                        clearTimeout(timeout);

                    }, false);

                }

            }

            $('button').longPress(function(){

                alert('长按')

            })