小笔记

2020-09-29

获取视频时长

getVideoDuration(file: File) {
  return new Promise(resolve => {
    const fileurl = URL.createObjectURL(file);
    const audioElement: HTMLAudioElement = new Audio(fileurl);
    let eventListener: any;
    eventListener = audioElement.addEventListener('loadedmetadata', () => {
      resolve(audioElement.duration);
      audioElement.removeEventListener('loadedmetadata', eventListener);
    });
  });
}

VueRouter

解决多次点击报错问题

const originalPush = Router.prototype.push;
Router.prototype.push = function push(location: any) {
  return (originalPush.call(this, location) as any).catch((err: any) => err);
};

重置默认路由

const router = new Router({
  routes
});

// 思路直接替换掉默认原有的路由
const resetRouter = () => {
  router.matcher = new Router({
    routes
  }).matcher;
}

对象过滤空内容

type FilterEmpty = (
  data: AxiosData,
  validation?: any[] | undefined
) => AxiosData;
/**
 * @param {Object} data Object对象，如{ a: null, b: 1, c: '' }
 * @param {Array} validation 传入需要过滤的数组，如[null, undefined, '', 0]
 * @returns {Object} 返回一个新的Object对象
 */
const filterEmpty: FilterEmpty = (
  data: AxiosData,
  validation?: any[]
) => {
  if (typeof data !== 'object') return {};
  const newObj: AxiosData = {};
  for (const key of Object.keys(data)) {
    if (!validation) {
      if (data[key] !== '' && data[key] !== undefined && data[key] !== null) {
        newObj[key] = data[key];
      }
    } else {
      if (!validation.includes(data[key])) {
        newObj[key] = data[key];
      }
    }
  }
  return newObj;
};

base64转Blob对象

const convertBase64UrlToBlob = (
  base64: string | ArrayBuffer | null
): Blob => {
  // 切割base64
  const arr = (base64 as string).split(',');
  const mime = ((arr[0] as string).match(/:(.*?);/) as RegExpMatchArray)[1];
  const bstr = atob(arr[1]);
  let n = bstr.length;
  const u8arr = new Uint8Array(n);
  while (n--) {
    u8arr[n] = bstr.charCodeAt(n);
  }
  return new Blob([u8arr], {
    type: mime
  }) as Blob;
};

判断是否pc

const isPc = () => {
  const agents = [
    'Android',
    'iPhone',
    'SymbianOS',
    'Windows Phone',
    'iPad',
    'iPod'
  ];
  return !!agents.filter(x => navigator.userAgent.includes(x)).length;
};