const createPixel = this.ctx.getImageData(this.pikaqiuX, this.pikaqiuY, 280, 280)

let data = createPixel.data;

let average = 0;

for (let i = 0; i < data.length; i+=4) {

data[i+3] = 0

}

this.ctx.putImageData(createPixel, this.pikaqiuX, this.pikaqiuY)

把a设置为0，在开发工具上可以透明图像， 在预览中没有发生变化