我正在尝试让网页荧屏保护程序在 Windows 10 上运行,但它使用的是 Internet Explorer :(
我希望线条的颜色在绘制时淡入下一种颜色。这在 Chrome 中作业正常,但在 Internet Explorer 中,strokeStyle 不会在每一步都更新。
我已经包含了一个显示问题的片段的链接:
function colorTween(from, to, step, maxStep) {
const newColor = [0,0,0,0];
from.forEach(function (fromVal, i) {
const toVal = to[i];
newColor[i] = fromVal (((toVal - fromVal)/maxStep)*step);
});
return newColor;
}
//init
const canvas = document.getElementById('canvas');
const ctx = canvas.getContext('2d');
canvas.width = window.innerWidth;
canvas.height = window.innerHeight;
ctx.lineWidth = 50;
ctx.lineCap = "round";
const fromColor = [0,0,0,1]; //black
const toColor = [255,255,255,1]; //white
const y = canvas.height/2;
let x = 0;
let prevX = 0;
//draw loop
setInterval(function () {
//increase x
x ;
//get color fading into next color
const drawColor = colorTween(fromColor, toColor, x, canvas.width);
//draw line segment
ctx.strokeStyle = "rgba(" drawColor[0] "," drawColor[1] "," drawColor[2] "," drawColor[3] ")";
ctx.beginPath();
ctx.moveTo(prevX, y);
ctx.lineTo(x, y);
ctx.stroke();
ctx.closePath();
//setup for next loop
prevX = x;
}, 1000/60);
body, canvas {
margin: 0;
padding: 0;
border: none;
overflow: none;
}
<!DOCTYPE html>
<html>
<head>
</head>
<body>
<canvas id="canvas"></canvas>
</body>
</html>
uj5u.com热心网友回复:
Internet Explorer 确实在 RGB CSS 值(strokeStyle
被决议为 CSS <color> 值)中阻塞了太多的十进制数。
您的colorTween
函式很可能会产生这样的十进制数,而 IE 将完全忽略该值。
为避免这种情况,请舍入您的 R、G 和 B 值,虽然我不确定是否需要,但您可能还想呼叫.toFixed()
Alpha 值(对于 R、G、B,实作无论如何都会丢弃小数,并且对于 alpha,最大粒度为 1/256,即 ~0.004)。
from.forEach(function (fromVal, i) {
const toVal = to[i];
const newVal = fromVal (((toVal - fromVal)/maxStep)*step);
newColor[i] = i===3 ? newVal.toFixed(3) : Math.round(newVal);
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