blob

/**
 * blobData 流文件
 * blobType 导出类型
 * fileName 导出文件名称
 * ..attr 其他信息
 */
export function dowloadBlobFile(blobData, blobType, fileName, ...attr) {
  const blob = new Blob([blobData], {
    type: blobType || "application/vnd.ms-excel",
  })
  const objectUrl = URL.createObjectURL(blob)
  const link = document.createElement("a")
  link.style.display = "none"
  link.href = objectUrl
  document.body.appendChild(link)
  link.click()
  document.body.removeChild(link)
}

export function dowloadFile(url) {
  const link = document.createElement("a")
  link.style.display = "none"
  link.href = url
  document.body.appendChild(link)
  link.click()
  document.body.removeChild(link)
  link.remove()
}

// base64  to blob二进制
function dataURItoBlob(dataURI) {
  const mimeString = dataURI.split(",")[0].split(":")[1].split(";")[0] // mime类型
  const byteString = atob(dataURI.split(",")[1]) //base64 解码
  const arrayBuffer = new ArrayBuffer(byteString.length) //创建缓冲数组
  const intArray = new Uint8Array(arrayBuffer) //创建视图

  for (let i = 0; i < byteString.length; i++) {
    intArray[i] = byteString.charCodeAt(i)
  }
  return new Blob([intArray], { type: mimeString })
}

// blob二进制 to base64
function blobToDataURI(blob, callback) {
  const reader = new FileReader()
  reader.onload = function (e) {
    callback(e.target.result)
  }
  reader.readAsDataURL(blob)
}