文章目录
前言
hello world欢迎来到前端的新世界
😜当前文章系列专栏:前端系列文章
🐱👓博主在前端领域还有很多知识和技术需要掌握,正在不断努力填补技术短板。(如果出现错误,感谢大家指出)🌹
💖感谢大家支持!您的观看就是作者创作的动力
代码
下方代码复制粘贴到ts文件中 然后下面是使用方式
javascript
export default function initLoginBg(){
var windowWidth = document.documentElement.clientWidth || document.body.clientWidth;
var windowHeight = document.documentElement.clientHeight || document.body.clientHeight;
// var windowWidth = window.clientWidth;
// var windowHeight = window.clientHeight;
var canvas = document.getElementById('canvas') as HTMLCanvasElement,
ctx = canvas.getContext('2d') as CanvasRenderingContext2D,
w = canvas.width = windowWidth,
h = canvas.height = windowHeight,
hue = 217,
stars:IntStart[] = [],
count = 0,
maxStars = 500;//星星数量
var canvas2 = document.createElement('canvas') ,
ctx2 = canvas2.getContext('2d') as CanvasRenderingContext2D;
canvas2.width = 100;
canvas2.height = 100;
var half = canvas2.width / 2,
gradient2 = ctx2.createRadialGradient(half, half, 0, half, half, half);
gradient2.addColorStop(0.025, '#CCC');
gradient2.addColorStop(0.1, 'hsl(' + hue + ', 61%, 33%)');
gradient2.addColorStop(0.25, 'hsl(' + hue + ', 64%, 6%)');
gradient2.addColorStop(1, 'transparent');
ctx2.fillStyle = gradient2;
ctx2.beginPath();
ctx2.arc(half, half, half, 0, Math.PI * 2);
ctx2.fill();
// End cache
function random(min:number, max=0) {
if (arguments.length < 2) {
max = min;
min = 0;
}
if (min > max) {
var hold = max;
max = min;
min = hold;
}
return Math.floor(Math.random() * (max - min + 1)) + min;
}
function maxOrbit(x:number, y:number) {
var max = Math.max(x, y),
diameter = Math.round(Math.sqrt(max * max + max * max));
return diameter / 2;
//星星移动范围,值越大范围越小,
}
interface IntStart{
orbitRadius:number;
radius:number;
orbitX:number;
orbitY:number
timePassed:number;
speed:number;
alpha:number;
draw:()=>void;
}
var Star = function(this: IntStart) {
this.orbitRadius = random(maxOrbit(w, h));
this.radius = random(60, this.orbitRadius) / 18;
//星星大小
this.orbitX = w / 2;
this.orbitY = h / 2;
this.timePassed = random(0, maxStars);
this.speed = random(this.orbitRadius) / 500000;
//星星移动速度
this.alpha = random(2, 10) / 10;
count++;
stars[count] = this;
}
Star.prototype.draw = function() {
var x = Math.sin(this.timePassed) * this.orbitRadius + this.orbitX,
y = Math.cos(this.timePassed) * this.orbitRadius + this.orbitY,
twinkle = random(10);
if (twinkle === 1 && this.alpha > 0) {
this.alpha -= 0.05;
} else if (twinkle === 2 && this.alpha < 1) {
this.alpha += 0.05;
}
ctx.globalAlpha = this.alpha;
ctx.drawImage(canvas2, x - this.radius / 2, y - this.radius / 2, this.radius, this.radius);
this.timePassed += this.speed;
}
for (var i = 0; i < maxStars; i++) {
new Star.prototype.constructor();
}
function animation() {
ctx.globalCompositeOperation = 'source-over';
ctx.globalAlpha = 0.5; //尾巴
ctx.fillStyle = 'hsla(' + hue + ', 64%, 6%, 2)';
ctx.fillRect(0, 0, w, h)
ctx.globalCompositeOperation = 'lighter';
for (var i = 1, l = stars.length; i < l; i++) {
stars[i].draw();
};
window.requestAnimationFrame(animation);
}
animation();
}
有动态效果的哦
使用
javascript
// 引入文件
import initLoginBg from "./init.ts";
import {useEffect} from "react";
const View = ()=>{
// 加载完这个组件之后,加载背景
useEffect(() => {
initLoginBg()
window.onresize = function () {
initLoginBg()
}
}, [])
return (
<div>
<canvas id="canvas" style={{display: "block"}}></canvas>
</div>
)
}
后言
创作不易,要是本文章对广大读者有那么一点点帮助 不妨三连支持一下,您的鼓励就是博主创作的动力