关于javascript:JS-文件base64FileBlobArrayBuffer互转

二进制互转

1. file对象转base64

 let reader = new FileReader(); reader.readAsDataURL(file[0]) console.log(reader)

2. base64 转成blob 上传

function dataURItoBlob(dataURI) {      var byteString = atob(dataURI.split(',')[1]);      var mimeString = dataURI.split(',')[0].split(':')[1].split(';')[0];      var ab = new ArrayBuffer(byteString.length);      var ia = new Uint8Array(ab);      for (var i = 0; i < byteString.length; i++) {          ia[i] = byteString.charCodeAt(i);      }      return new Blob([ab], {type: mimeString});  }

3. blob 转成ArrayBuffer

let blob = new Blob([1,2,3,4])let reader = new FileReader();reader.onload = function(result) {    console.log(result);}reader.readAsArrayBuffer(blob);

4. buffer 转成blob

let blob = new Blob([buffer])

5. base64 转 file

const base64ConvertFile = function (urlData, filename) { // 64转file  if (typeof urlData != 'string') {    this.$toast("urlData不是字符串")    return;  }  var arr = urlData.split(',')  var type = arr[0].match(/:(.*?);/)[1]  var fileExt = type.split('/')[1]  var bstr = atob(arr[1])  var n = bstr.length  var u8arr = new Uint8Array(n)  while (n--) {    u8arr[n] = bstr.charCodeAt(n);  }  return new File([u8arr], 'filename.' + fileExt, {    type: type  });}