fileToBase64 (file) {
  return new Promise((resolve, reject) => {
    // 創(chuàng)建一個(gè)新的 FileReader 對(duì)象
    const reader = new FileReader();
    // 讀取 File 對(duì)象
    reader.readAsDataURL(file);
    // 加載完成后
    reader.onload = function () {
      // 將讀取的數(shù)據(jù)轉(zhuǎn)換為 base64 編碼的字符串
      const base64String = reader.result.split(",")[1];
      // 解析為 Promise 對(duì)象，并返回 base64 編碼的字符串
      resolve('data:image/jpeg;base64,' + base64String);
    };
    // 加載失敗時(shí)
    reader.onerror = function () {
      reject(new Error("Failed to load file"));
    };
  })
}

base64ToFile(base64Data) {
  // 分割base64
  const arr = base64Data.split(','); 
  // 獲取類型
  const mime = arr[0].match(/:(.*?);/)[1];
  // 解析base字符串
  const bstr = window.atob(arr[1]); 
  const n = bstr.length; 
  // base64文件數(shù)據(jù)讀取
  const u8arr = new Uint8Array(n);
  for (let i = 0; i < n; i += 1) {
    u8arr[i] = bstr.charCodeAt(i);
  }
  return new File([u8arr], '', { type: mime });
}

base64ToBlob(base64Data) {
  // 分割base64
  const temp = base64Data.split(','); 
  // 獲取類型
  const mime = temp[0].match(/:(.*?);/)[1];
  // 解碼使用 base-64 編碼的字符串
  const raw = window.atob(temp[1]);
  const rawLength = raw.length;
  // base64文件數(shù)據(jù)讀取
  const uInt8Array = new Uint8Array(rawLength);
  for (let i = 0; i < rawLength; i += 1) {
    uInt8Array[i] = raw.charCodeAt(i);
  }
  return new Blob([uInt8Array], {type: mime})
}

blobToBase64 (blob) {
  return new Promise((resolve,reject) => {
    const reader = new FileReader();
    reader.readAsDataURL(blob);
    reader.onload = () => {
      const base64 = reader.result;
      resolve(base64);
    }
    reader.onerror = function () {
      reject(new Error("Failed to load file"));
    };
  })
}

const blob = URL.createObjectURL(file)

const file = new File([blob], fileName, { type: fileType, lastModified: Date.now() });