qjkankan_v1.1.1/packages/qjkankan-editor/src/utils/file.js

// 媒体名称
export const mediaTypes = {
  image: "图片",
  video: "视频",
  audio: "音频",
};

// 媒体扩展类型
export const mediaMimes = {
  image: ["jpg", "png", "jpeg", "bmp", "gif"],
  audio: ["mp3", "aac", "ogg", "wav" /* , "m4a" */],
  video: ["mp4", "mov", "quicktime" /* ,"webm", "rmvb", "wmv" */], //ios:mov
};

// 媒体大小显示(MB)
export const mediaMaxSize = {
  image: 10,
  video: 20,
  audio: 5,
};

/**
 * 获取媒体扩展类型
 * @param {Stirng} filename 文件名称
 */
export const getMime = (filename) => {
  if (!filename || filename.indexOf(".") === -1) {
    return "";
  }

  return filename.split(".").pop().toLowerCase();
};

/**
 * 在路径中获取文件名
 * @param {*} path
 */
export const getFilename = (path) => {
  const segment = (path || "").split("/");
  return segment[segment.length - 1];
};

/**
 * 检测媒体文件是否超过预设限制
 * @param {String} type 媒体类型
 * @param {Number} size 文件大小
 */
export const checkSizeLimit = (type, size) => {
  size = size / 1024 / 1024;

  return size <= mediaMaxSize[type];
};

export const checkSizeLimitFree = (size, limit) => {
  size = size / 1024 / 1024;

  return size <= limit;
};

/**
 * 检测媒体类型
 * @param {String} type 媒体类型
 * @param {String} filename 文件名称
 */
export const checkMediaMime = (type, filename) => {
  const mime = getMime(filename);
  const find = mediaMimes[type];
  if (!find) {
    return false;
  }

  return find.indexOf(mime) !== -1;
};

export const base64ToBlob = (base64) => {
  let arr = base64.split(","),
    mime = arr[0].match(/:(.*?);/)[1],
    bstr = atob(arr[1]),
    n = bstr.length,
    u8arr = new Uint8Array(n);
  while (n--) {
    u8arr[n] = bstr.charCodeAt(n);
  }
  return new Blob([u8arr], { type: mime });
};

export const base64ToDataURL = (base64) => {
  return window.URL.createObjectURL(base64ToBlob(base64));
};

export const blobToBase64 = function (blob) {
  return new Promise((resolve) => {
    var reader = new FileReader();
    reader.onload = function () {
      resolve(reader.result);
    };
    reader.readAsDataURL(blob);
  });
};

/**
 * 获取图片文件尺寸
 * @param {*} file
 */
export const getImgWH = (file) => {
  return new Promise((resolve, reject) => {
    var reader = new FileReader();
    //读取图片文件
    let url = URL.createObjectURL(file);
    var image = new Image();
    //FileReader获得Base64字符串
    image.src = url;
    image.onload = function () {
      console.log("图片加载成功");
      //获得图片高宽
      var height = this.height;
      var width = this.width;
      resolve({
        height,
        width,
      });
    };
    image.onerror = function (e) {
      reject({ message: "loadFile Error" });
    };

    // reader.readAsDataURL(file);
    // reader.onload = function (e) {
    //   //初始化JavaScript图片对象
    //   var image = new Image();
    //   //FileReader获得Base64字符串
    //   image.src = e.target.result;
    //   image.onload = function () {
    //     console.error("图片加载成功");
    //     //获得图片高宽
    //     var height = this.height;
    //     var width = this.width;
    //     resolve({
    //       height,
    //       width,
    //     });
    //   };
    //   image.onerror = function (e) {
    //     console.error("图片加载失败",e);
    //     reject({
    //       height: 0,
    //       width: 0,
    //     });
    //   };
    // };
  });
};

/**
 * 转化字节单位
 * @param {*} file
 */
export const changeByteUnit = (x) => {
  const units = ["KB", "MB", "GB", "TB", "PB", "EB", "ZB", "YB"];
  let l = 0,
    n = parseInt(x, 10) || 0;

  while (n >= 1024 && ++l) {
    n = n / 1024;
  }
  return n.toFixed(n < 10 && l > 0 ? 2 : 0) + units[l];
};