JS压缩图片let canvas = document.createElement('canvas') // 创建Can

let canvas = document.createElement('canvas') // 创建Canvas对象(画布)

let context = canvas.getContext('2d')

let img = new Image()

img.src = photoArr[i].content // 指定图片的DataURL(图片的base64编码数据)

img.onload = () =>{

    canvas.width = img.width

    canvas.height = img.height

    context.drawImage(img, 0, 0, canvas.width, canvas.height)

    if(photoArr[i].file.size/1024>2048){//如果图片大小大于2M

            photoArr[i].content = canvas.toDataURL(photoArr[i].file.type, 0.92)

    // 0.92为默认压缩质量 type为image格式 如jpg、png

    }

    console.log(photoArr[i].content);

}