jQuery实现评论弹幕、弹幕漂浮、滚动代码
1、html代码和jquery代码:
<!DOCTYPE html>
<html>
<head lang="en">
<meta charset="UTF-8">
<title>document</title>
<meta http-equiv="Content-Type" content="text/html; charset=utf-8"/>
<meta name="viewport" content="width=device-width,height=device-height,inital-scale=1.0,maximum-scale=1.0, minimun-scale=1.0,user-scalable=no;"> <meta name="apple-mobile-web-app-capable" content="yes">
<meta name="apple-mobile-web-app-status-bar-style" content="black">
<meta name="format-detection" content="telephone=no">
<script type="text/javascript" src="js/auto_rem.js"></script>
<link rel="stylesheet" href="css/style.css"/>
html滚动效果代码
</head>
<body>
<header class="fixed top-nav">
<a class="back"></a>
<span class="title">公屏</span>
<a class="home"></a>
</header>
<div class="gp-body">
<div class="main-box">
<ul class="all-list">
</ul>
</div>
<div class="fixed send-ms flex">
<div class="ipt s_txt flex1" contenteditable="true"></div>
<span class="btn s_btn">发送</span>
</div>
</div>
</body>
<script src="libs.baidu/jquery/2.1.4/jquery.min.js"></script>
<script type="text/javascript">
$(function() {
//发表评论
$.getJSON('./js/test.json', function(result) {
actFn($('.all-list'), result)
})
function actFn(tar, data) {
var data = data;
startTranslate();
appendNewItem();
function startTranslate() {
var key = 0;
var leng = data.length;
var time = setInterval(function() {
if (key >= leng) {
clearInterval(time);
return;
};
var _html = itemHtml(data[key].img_src, data[key].grade, data[key].words)
key++;
tar.append(_html);
translateFn();
}, 400);
}
function appendNewItem() {
$(".s_btn").click(function() {
var text = $(".s_txt").html();
if (text == '') return;
var _html = itemHtml('./img/heads.png', '最强王者', text)
tar.prepend(_html);
$(".s_txt").html('');
translateFn();
});
}
function itemHtml(img, grade, words) {
var _html = "<li class='item'>" +
"<span class='img-box'>" +
"<img src='" + img + "' alt=''>" +
"</span>" +
"<p class='para'>" +
"<em class='grade'>" + grade + "</em>" +
"<span class='words'>" + words + "</span>" +
"</p>" +
"</li>";
return _html;
}
var initTop = 20;
var _top = initTop;
function translateFn() {
tar.find("li[class!='had']").show().each(function(item, key) {
if ($(this).hasClass('had')) return;
var that = this;
var twidth = $(this).width();
var _left = $(window).width() + twidth;
var rd = Math.random() * 100;
var rdColor = getRandomColor();
var _height = $(window).height();
var time = 20000;
if (_top > _height - 150) {
if (initTop == 20) {
_top = initTop = 60;
} else {
_top = initTop = 20;
}
}
$(this).find('.grade').css({
color: rdColor
})
$(this).css({
top: _top,
right: "-" + twidth + "px"
});
$(this).css({
transform: "translateX(-" + (_left + rd + 200) + "px)"
}).addClass('had');
_top = _top + 80;
});
}
//随机获取颜⾊值
function getRandomColor() {
return '#' + (function(h) {
return new Array(7 - h.length).join("0") + h
})((Math.random() * 0x1000000 << 0).toString(16))
}
}
});
//初始化弹幕
</script>
</html>
2、scss代码:
.gp-body {
@extend .main;
width: 100%;
height: 100%;
.main-box {
background: url("../img/gp-bg.jpg") no-repeat;
background-size: 100% 100%;
height: 100%;
width: 100%;
overflow: hidden;
overflow-y: scroll;
.all-list {
position: relative;
}
.item {
display: inline-block;
position: absolute;
top: 0;
right: -100%;
display: none;
transition: transform 12s ease-in-out;  //css设置移动的时间及表现            ;
.para {
color: white;
font-size: 14px;
line-height: 37px;
display: inline-block;
overflow: hidden;
border-radius: 20px;
background: rgba(0, 0, 0, 0.6);
padding: 0 10px;
max-width: 400px;
white-space: nowrap;
text-overflow: ellipsis;
.grade {
margin-right: 3px;
}
}
.img-box {
float: left;
img {
width: 35px;
height: 35px;
border-radius: 100%;
margin-right: 5px;
}
}
}
}
}
评论弹幕的主要思想是重看不到的屏幕位置移动到屏幕看到的位置，最后消失，所以需要移动，这⾥采⽤的是css3 的translate ⽅法，可以实现⽬标的移动⽽在移动端不卡顿。
⾄于每条屏幕的飘移过程中之间的位置关系需要良好的设置，⽐如间隔时间插⼊每条评论，这样就会在垂直位置上错开，还有就是top位置的关系上的调节等，⽐如奇数排设置top20，偶数排设置60，这样⼜可以错开⽔平⽅⾯的每条评论的位置。如下的错开:
以下是最终效果图:
以下是demo数据:
[{
"img_src": "./img/heads.png",
"grade": "最强王者",
"words": "灯笼裤飞机失控打笼裤飞机失控打笼裤飞机失控打笼裤飞机失控打笼裤飞机失控打笼裤飞机失控打飞机" }, {
"img_src": "./img/heads.png",
"grade": "最强王者",
"words": "灯笼裤飞机失控飞机失控飞机失控打飞机"
}, {
"img_src": "./img/heads.png",
"grade": "最强王者",
"words": "灯笼裤飞机失控打飞机"
}, {
"img_src": "./img/heads.png",
"grade": "最强王者",
"words": "灯笼裤飞机失控飞机失控飞机失控打飞机"
}, {
"img_src": "./img/heads.png",
"grade": "最强王者",
"words": "灯笼裤飞机失控飞机失控飞机失控打飞机"
}, {
"img_src": "./img/heads.png",
"grade": "荣耀黄⾦",
"words": "灯笼裤飞机失控打飞机"
}, {
"img_src": "./img/heads.png",
"grade": "最强王者",
"words": "灯笼裤飞机失控打飞机last"
}]