基于JavaScript实现雪花许愿墙特效

class Snowflake {
  constructor() {
    this.x = 0;
    this.y = 0;
    this.vx = 0;
    this.vy = 0;
    this.radius = 0;
    this.alpha = 0;
    this.reset();
  }
  reset() {
    this.x = this.randBetween(0, window.innerWidth);
    this.y = this.randBetween(0, -window.innerHeight + 672);
    this.vx = this.randBetween(-3, 3);
    this.vy = this.randBetween(2, 5);
    this.radius = this.randBetween(1, 4);
    this.alpha = this.randBetween(0.1, 0.9);
  }
  randBetween(min, max) {
    return min + Math.random() * (max - min);
  }
  update() {
    this.x += this.vx;
    this.y += this.vy;
    if (this.y + this.radius > window.innerHeight) {
      this.reset();
    }
  }
}
class Snow {
  constructor() {
    this.canvas = document.createElement('canvas');
    this.ctx = this.canvas.getContext('2d');
    document.body.appendChild(this.canvas);
    window.addEventListener('resize', () => this.onResize());
    this.onResize();
    this.updateBound = this.update.bind(this);
    requestAnimationFrame(this.updateBound);
    this.createSnowflakes();
  }
  onResize() {
    console.log(this.width, 'width');
    console.log(this.height, 'height');
    this.width = window.innerWidth;
    this.height = window.innerHeight;
    this.canvas.width = this.width;
    this.canvas.height = this.height + 672;
  }
  createSnowflakes() {
    const flakes = window.innerWidth / 4;
    this.snowflakes = [];
    for (let s = 0; s < flakes; s++) {
      this.snowflakes.push(new Snowflake());
    }
  }
  update() {
    this.ctx.clearRect(0, 0, this.width, this.height);
    for (let flake of this.snowflakes) {
      flake.update();
      this.ctx.save();
      this.ctx.fillStyle = '#FFF';
      this.ctx.beginPath();
      this.ctx.arc(flake.x, flake.y, flake.radius, 0, Math.PI * 2);
      this.ctx.closePath();
      this.ctx.globalAlpha = flake.alpha;
      this.ctx.fill();
      this.ctx.restore();
    }
    requestAnimationFrame(this.updateBound);
  }
}
new Snow();

//转换时间格式
  function formatDated(date) {
    var date = new Date(date);
    var YY = date.getFullYear() + '-';
    var MM = (date.getMonth() + 1 < 10 ? '0' + 
(date.getMonth() + 1) : date.getMonth() + 1) + '-';
    var DD = (date.getDate() < 10 ? '0' +
(date.getDate()) :
date.getDate());
    var hh = (date.getHours() < 10 ? '0' + 
date.getHours() : 
date.getHours()) + ':';
    var mm = (date.getMinutes() < 10 ? '0' + 
date.getMinutes() :
date.getMinutes()) + ':';
    var ss = (date.getSeconds() < 10 ? '0' + 
date.getSeconds() : date.getSeconds());
    return YY + MM + DD +" "+hh + mm + ss;
}
function timeChange(){
var datas =[]
var idList=0;
var timer= setInterval(() => {
//控制文字的说明
for( i=0;i<2;i++){
    datas.push({
        id:idList,
        name:"歌谣",
        content:" 在过往的岁月中,我遇到了形形色色的人和事情。有的人坚持，有的人放弃。有的人逆袭，有的人失败。最好的种树是十年前其次是现在。很高兴遇到你,愿你的人生多姿多彩，幸福绵绵，好事连连。歌谣很棒谢谢你的一键三连",
        time:formatDated(new Date())
    })
    }
    idList++
    console.log(idList,"idList")
   if(idList==5){
    clearInterval(timer)
   }
var content = document.getElementById("content");
var zIndex = 1;
for (var i = 0; i < datas.length; i++) {
    var data = datas[i];
    var div = document.createElement("div");
    div.className = "tip1";
    div.id = "cc" + data.id;
    content.appendChild(div);
    //设置随机数
    let num=parseInt(Math.random()*10000)
    div.innerHTML = '<div class="tip_h" title="双击关闭纸条">'
            + '<div class="num">第'+num+'条'+ data.time + '</div>'
            + '<div class="close" title="关闭纸条">×</div>'
            + '<div class="clr"></div>'
            + '</div>'
            + '<div class="tip_c">'
            + data.content
            + '</div>'
            + '<div class="tip_f">'
            + '<div class="icon">'
            + '<img src="images/bpic_1.gif" alt="" title="">'
            + '</div>'
            + '<div class="name">' + data.name + '</div>'
            + '<div class="clr"></div>'
            + '</div>';
    // 控制贴纸的位置
    var x = parseInt(Math.random() * 1500)+200;
    var y = parseInt(Math.random() * 700);
    div.style.left = x + "px";
    div.style.top = y + "px";
    div.onclick = function () {
        zIndex++;
        this.style.zIndex = zIndex;
    };
    var closeDiv = div.children[0];
    closeDiv.ondblclick = function () {
        this.parentNode.style.display = "none";
    };
    var x = closeDiv.children[1];
    x.onclick = function () {
        this.parentNode.parentNode.style.display = "none";
    };
}
},2000)
}
window.onload = timeChange;

body {
    margin: 0 auto;
    padding: 0px;
    font-size: 12px;
    background: url(../images/bg.gif) repeat center 36px;
    text-align: center;
    background-color: #c30230;
}  
#content .tip1, #content .tip2, #content .tip3, #content 
.tip4, #content .tip5, #content .tip6, #content .tip7, #content .tip8 {
    position: absolute;
    width: 227px;
    left: 200px;
    top: 100px;
}
#content .tip1 .tip_h {
    background: url(../images/tip1_h.gif) no-repeat left top;
}
#content .tip1 .tip_h, #content .tip2 .tip_h, #content .tip3 .tip_h, 
#content .tip4 .tip_h, #content .tip5 .tip_h, #content .tip6 .tip_h,
 #content .tip7 .tip_h, #content .tip8 .tip_h {
    width: 227px;
    padding-top: 45px;
    height: 23px;
    text-align: left;
    cursor: move;
}
#content .tip1 .tip_c {
    background: url(../images/tip1_c.gif) repeat-y;
}
#content .tip1 .tip_c, #content .tip2 .tip_c, #content .tip3 .tip_c, 
#content .tip4 .tip_c, #content .tip5 .tip_c, #content .tip6 .tip_c,
 #content .tip7 .tip_c, #content .tip8 .tip_c {
    width: 200px;
    padding-left: 12px;
    padding-right: 15px;
    min-height: 40px;
    text-align: left;
    line-height: 20px;
    max-height: 160px;
    word-wrap: break-word;
    word-break: break-all;
    overflow: hidden;
}
#content .tip1 .tip_f {
    background: url(../images/tip1_f.gif) no-repeat left top;
}
#content .tip1 .tip_f, #content .tip2 .tip_f, #content .tip3 .tip_f,
 #content .tip4 .tip_f, #content .tip5 .tip_f, #content .tip6 .tip_f, 
#content .tip7 .tip_f, #content .tip8 .tip_f {
    width: 227px;
    height: 53px;
    padding-top: 20px;
}
#content .close, #content .close2 {
    float: left;
    font-size: 12px;
    cursor: pointer;
    color: #000000;
}
.clr {
    clear: both;
    overflow: auto;
    display: block;
    height: 0px;
}
#content .icon {
    float: left;
    width: 35px;
    padding-left: 15px;
    height: 35px;
    text-align: center;
}
#content .name {
    float: right;
    padding-right: 15px;
    text-align: right;
    font-size: 14px;
    line-height: 35px;
    color: #C0F;
}
#content .num {
    float: left;
    padding-left: 7px;
    width: 195px;
}

<!DOCTYPE html>
<html>
<head lang="en">
    <meta charset="UTF-8">
    <title>歌谣许愿墙</title>
    　<link rel="stylesheet" type="text/css" href="./css/style.css" rel="external nofollow"  />
    
</head>
<body>
<div id="content">
</div>
<script  src="./js/index.js"></script>
<script  src="./js/script.js"></script>
<script>
  
 
</script>
</body>
</html>