下面的代码在开发者工具和安卓手机上能画出个绿方块, 画不出图片, 在ios上方块和图片都画不出来

图片在 项目根目录/images 下  是有的,  在开发者工具里面network里是加载了图片的

console出来canvas是有的, ctx也有, img也加载上了

const canvas = wx.createCanvas()
    , ctx = canvas.getContext("2d")
    , img = wx.createImage()
    , {screenWidth, screenHeight} = wx.getSystemInfoSync();

img.src = "images/background.png";
img.width = screenWidth;
img.height = screenHeight;

ctx.drawImage(img, 0, 0, screenWidth, screenHeight);

console.log(canvas, ctx, img);

ctx.fillStyle = "#00ff00";
ctx.fillRect(0, 0, 200, 200);