Vue3 实现图片的帧动画方案分享

一、纯 JS （有性能问题会卡顿）

      <div class="robot-box"><img ref="robotImgRef" src="/Greet/Greet_00000.png" alt="" /></div>

const delay = 30;
const imgCount = 109;
let i = 0;
const robotImgRef = ref<HTMLImageElement | null>(null);
const animation = (i) => {if (i === imgCount) {i = 0;animation(i);return;}let path;if (Number(i) < 10) {path = '0000' + i;} else if (Number(i) < 100) {path = '000' + i;} else if (Number(i) < 1000) {path = '00' + i;}robotImgRef.value.src = `/Greet/Greet_${path}.png`;robotImgRef.value.onload = () => {setTimeout(() => {animation(i + 1);}, delay);};
};onMounted(() => {nextTick(() => {animation(0);});
});

二、window.requestAnimationFrame()

window.requestAnimationFrame——MDN

window.requestAnimationFrame() 告诉浏览器——你希望执行一个动画，并且要求浏览器在下次重绘之前调用指定的回调函数更新动画。该方法需要传入一个回调函数作为参数，该回调函数会在浏览器下一次重绘之前执行。

onMounted(() => {nextTick(() => {rAF(animation, 60);});
});

const imgCount = 109;
let i = 0;
const robotImgRef = ref<HTMLImageElement | null>(null);
const animation = () => {if (i === imgCount) {// 重新开始i = 0;return;}let path;if (Number(i) < 10) {path = '0000' + i;} else if (Number(i) < 100) {path = '000' + i;} else if (Number(i) < 1000) {path = '00' + i;}if (robotImgRef.value) {robotImgRef.value.src = `/Greet/Greet_${path}.png`;}i++;
};
/*** @param {number} [fps] - 帧率* @param {function} callback - 动画逻辑* @return {function} cancelRFA  - 取消播放*/function rAF(callback, fps = 24) {let last = Date.now();let delta = last;const interval = 1000 / fps;let cancel = false;function draw() {if (cancel) return;requestAnimationFrame(draw);let now = Date.now();delta = now - last;if (delta > interval) {/* 这里不能简单last = now，否则出现细微时间差问题。例如fps= 10，每帧100ms，而现在每16ms（60fps）执行一次draw。16*7=112>100，需要7次才实际绘制一帧。这个情况下，实际10帧需要 112*10=1120ms>1000ms 才绘制完成。当 now - (delta % interval) 时，会将时间修正 delta % interval = 12ms，实际10帧需要 112+(112-12)*9=1012ms 绘制完成。*/last = now - (delta % interval);callback();}}draw();return function cancelRAF() {cancel = true;};
}