let bgcImage = 'http://192.168.0.83:9080/files/4a9c3056-9b9b-4b41-b8e2-fd9f27023c41.jpg'

let image = new Image()

    image.crossOrigin = '' // 必须有这个

    image.src = bgcImage

    image.onload = () => { // 图片加载完成后，调用getBase64Image方法

        let base64ImageSrc = getBase64Image(image)

        console.log(base64ImageSrc )

}

// url转base64

export function getBase64Image(image, width, height) { // width、height调用时传入具体像素值，控制大小 ,不传则默认图像大小

  let canvas = document.createElement('canvas')

  canvas.width = width !== undefined ? width : image.width

  canvas.height = height !== undefined ? height : image.height

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

  ctx.drawImage(image, , , canvas.width, canvas.height)

  let ext = image.src.substring(image.src.lastIndexOf('.') + ).toLowerCase()

  let dataURL = canvas.toDataURL('image/' + ext)

  return dataURL

}

// base64转file

export function dataURLtoFile (dataurl, filename) {

  let arr = dataurl.split(',')

  let mime = arr[].match(/:(.*?);/)[]

  let bstr = atob(arr[])

  let n = bstr.length

  let u8arr = new Uint8Array(n)

  while (n--) {

    u8arr[n] = bstr.charCodeAt(n)

  }

  return new File([u8arr], filename, { type: mime })

}