我需要在画布上绘制一个带透明背景的图像。我有一段代码应该可以做到这一点:
var can = document.getElementById('canvasId');
var ctx = can.getContext('2d');
ctx.fillRect(50,50,500,500); // something in the background
var img = new Image();
img.onload = function() {
ctx.drawImage(img, 0, 0);
}
img.src = "https://istack.dev59.com/7JXBD.webp"; //transparent png
<canvas id="canvasId"></canvas>