我想抽2条黑线HTML5画布:如何摆脱HTML5画布中的默认不透明度?
的jsfiddle:http://jsfiddle.net/KFNt5/ 的Javascript:
var canvas = document.createElement('canvas');
canvas.height = 150;
canvas.width = 150;
var canvasContext = canvas.getContext('2d');
canvasContext.beginPath();
// Draw the red line.
canvasContext.strokeStyle = '#000';
canvasContext.moveTo(10, 0);
canvasContext.lineTo(10, 100);
canvasContext.stroke();
// Draw the green line.
canvasContext.moveTo(50, 0);
canvasContext.lineTo(50, 100);
canvasContext.stroke();
document.body.appendChild(canvas);
然而,行至右边是灰色的,这意味着它是半透明的。我如何确保默认不透明度为100(根本不透明)?
谢谢,它可行,但这很奇怪。如何在两个方向上转换半个像素关闭抗锯齿? – dangerChihuahua007
实际上并没有关闭反锯齿功能。它只是确保一个像素宽的水平和垂直线不跨越像素边界。这是一个很好的解释:https://developer.mozilla.org/en-US/docs/Canvas_tutorial/Applying_styles_and_colors#A_lineWidth_example –