本文实例讲述了jQuery实现的上拉刷新功能组件。分享给大家供大家参考，具体如下：
技术要点：
1、jQuery的插件写法
2、上拉刷新步骤分解
3、css样式
jQuery的插件写法：
$.fn.pluginName = function() {
return this.each(function () {
fn();
})
};
上拉刷新步骤分解：
上拉刷新可以分解成三个部分：一是开始（start），记录当前鼠标的位置；二是移动（move），根据下拉的位移响应不同的视图；三是结束（end），刷新页面。
;!function ($) {
"use strict";
var PTR = function (ele) {
this.container = $(ele);
this.container.addClass('pull-to-refresh');
this.distance = 60; // 设置参考的下拉位移
this.attachEvent();
};
// 判断是否有touch事件发生
var isTouch = (function () {
var isSupportTouch = !!'ontouchstart' in document || window.documentTouch;
return isSupportTouch;
})();
var touchEvents = {
start: isTouch ? 'touchstart': 'mousedown',
move: isTouch ? 'touchmove':'mousemove',
end: isTouch ? 'touchend': 'mouseup'
};
// 获取事件发生时相对于文档的距离（含滚动距离）
function getTouchPosition(e) {
var e = e.orinalEvent || e;
console.log(e)
if(e.type === 'touchstart' || e.type === 'touchmove' || e.type === 'touchend') {
return {
x: e.targetTouches[0].pageX,
y: e.targetTouches[0].pageY
}
}else {
return {
x: e.pageX,
y: e.pageY
}
}
};
PTR.prototype.touchStart = function (e) {
var p = getTouchPosition(e);
this.start = p;
this.diffX = this.diffY = 0;
};
PTR.prototype.touchMove = function (e) {
if(this.container.hasClass('refreshing')) return;
if(!this.start) return false;
var p = getTouchPosition(e);
this.diffX = p.x - this.start.x;
this.diffY = p.y - this.start.y;
if(this.diffY < 0) return;
this.container.addClass('touching');
e.preventDefault();
e.stopPropagation();
// 设置container的位移小于页面滚动的距离，给人一种用力下拉的错觉，提升用户体验
this.diffY = Math.pow(this.diffY, .8);
this.container.css('transform', 'translate3d(0,'+ this.diffY +'px, 0)');
if(this.diffY < this.distance) {
this.container.removeClass('pull-up').addClass('pull-down')
}else {
this.container.removeClass('pull-down').addClass('pull-up')
}
};
PTR.prototype.touchEnd = function (e) {
var _this = this;
this.start = false;
this.container.removeClass('pull-down');
this.container.removeClass('pull-up');
this.container.removeClass('touching');
this.container.css('transform','');
if(this.diffY >= this.distance) {
this.container.addClass('refreshing');
this.container.trigger('pull-to-refresh')
}
};
// 事件处理程序，通过$.proxy(fn, content)绑定执行函数的上下文。
PTR.prototype.attachEvent = function () {
var ele = this.container;
ele.on(touchEvents.start, $.proxy(this.touchStart, this));
ele.on(touchEvents.move, $.proxy(this.touchMove, this));
ele.on(touchEvents.end, $.proxy(this.touchEnd, this));
};
// 实例化构造函数
var pullToRefresh = function (ele) {
new PTR(ele)
};
var pullToRefreshDone = function (ele) {
$(ele).removeClass('refreshing');
};
// jQuery 插件编写的一般模式
$.fn.pullToRefresh = function () {
// return 是插件可链式调用
// this 在这里是一个jQuery对象，相当于$(ele)。因为在即时执行函数作用域中，没必要用“$(this)”的方式来把this包裹到一个jQuery对象中，因为this本身已经是被包装好的jQuery对象。
// this.each()使插件代码为多元素集合中的每个元素单独起作用
return this.each(function () {
pullToRefresh(this);
})
};
$.fn.pullToRefreshDone = function () {
return this.each(function () {
pullToRefreshDone(this);
})
}
}(window.jQuery);
HTML代码如下：
Title p { margin-top: 0; } ↓ 下拉刷新 释放刷新 正在刷新 Lorem ipsum dolor sit amet, consectetur adipisicing elit. Accusamus amet aperiam, architecto at aut beatae dignissimos eaque est ex fugi at incidunt inventore natus nemo nostru m omnis quos repellat ut voluptas!
Lorem ipsum dolor sit amet, consectetur adipisicing elit. Accusamus amet aperiam, architecto at aut beatae dignissimos eaque est ex fugi at incidunt inventore natus nemo nostru m omnis quos repellat ut voluptas!
Lorem ipsum dolor sit amet, consectetur adipisicing elit. Accusamus amet aperiam, architecto at aut beatae dignissimos eaque est ex fugi at incidunt inventore natus nemo nostru m omnis quos repellat ut voluptas!
Lorem ipsum dolor sit amet, consectetur adipisicing elit. Accusamus amet aperiam, architecto at aut beatae dignissimos eaque est ex fugi at incidunt inventore natus nemo nostru m omnis quos repellat ut voluptas!
Lorem ipsum dolor sit amet, consectetur adipisicing elit. Accusamus amet aperiam, architecto at aut beatae dignissimos eaque est ex fugi at incidunt inventore natus nemo nostru m omnis quos repellat ut voluptas!
Lorem ipsum dolor sit amet, consectetur adipisicing elit. Accusamus amet aperiam, architecto at aut beatae dignissimos eaque est ex fugi at incidunt inventore natus nemo nostru m omnis quos repellat ut voluptas!
Lorem ipsum dolor sit amet, consectetur adipisicing elit. Accusamus amet aperiam, architecto at aut beatae dignissimos eaque est ex fugi at incidunt inventore natus nemo nostru m omnis quos repellat ut voluptas!
Lorem ipsum dolor sit amet, consectetur adipisicing elit. Accusamus amet aperiam, architecto at aut beatae dignissimos eaque est ex fugi at incidunt inventore natus nemo nostru m omnis quos repellat ut voluptas!
CSS代码如下：
.pull-to-refresh {
margin-top: -50px;
transition: transform .4s;
}
.pull-to-refresh .pull-to-refresh-preloader,
.pull-to-refresh .up,
.pull-to-refresh .refresh {
display: none;
}
.pull-to-refresh.refreshing {
transform: translate3d(0,50px,0);
}
.refreshing .pull-to-refresh-arrow,
.refreshing .down,
.refreshing .up {
display: none;
}
.refreshing .refresh,
.refreshing .pull-to-refresh-preloader {
display: inline-block;
}
.pull-to-refresh_layer {
height: 30px;
line-height: 30px;
padding-bottom: 10px;
}
.pull-down .pull-to-refresh_layer .up,
.pull-down .pull-to-refresh_layer .refresh {
display: none;
}
.pull-down .pull-to-refresh_layer .down{
display: inline-block;
}
.pull-up .pull-to-refresh_layer .up{
display: inline-block;
}
.pull-up .pull-to-refresh_layer .down,
.pull-up .pull-to-refresh_layer .refresh {
display: none;
}
.pull-up .pull-to-refresh-arrow {
transform: rotate(180deg) translate3d(0, 0, 0);
}
.pull-to-refresh-arrow {
display: inline-block;
z-index: 10;
margin-right: 4px;
transition-duration: 300ms;
transform: rotate(0deg) translate3d(0, 0, 0);
}
.pull-to-refresh_layer {
display: inline-block;
}
.pull-to-refresh-preloader {
display: inline-block;
}
.pull-down {
}
.pull-up {
}
.down {
display: inline-block;
}
.up {
display: inline-block;
}
.refresh {
display: inline-block;
}
感兴趣的朋友可以使用在线HTML/CSS/Javascript代码运行工具 http://tools.jb51.net/code/HtmlJsRun 测试上述代码运行效果。
更多关于jQuery相关内容感兴趣的读者可查看本站专题：《jQuery页面元素操作技巧汇总》、《jQuery常见事件用法与技巧总结》、《jQuery常用插件及用法总结》、《jQuery扩展技巧总结》及《jquery选择器用法总结》
希望本文所述对大家jQuery程序设计有所帮助。
