/**
 * Unix時(shí)間戳轉(zhuǎn)換為當(dāng)前時(shí)間多久之前
 * @param timespan int     Unix時(shí)間戳
 * @return timeSpanStr string   轉(zhuǎn)換之后的前臺(tái)需要的字符串
 */
function Ftime (timespan) {
  var dateTime = new Date(timespan * 1000);
  var year = dateTime.getFullYear();
  var month = dateTime.getMonth() + 1;
  var day = dateTime.getDate();
  var hour = dateTime.getHours();
  var minute = dateTime.getMinutes();
  //當(dāng)前時(shí)間
  var now = Date.parse(new Date()); //typescript轉(zhuǎn)換寫法
  var milliseconds = 0;
  var timeSpanStr;
  //計(jì)算時(shí)間差
  milliseconds = (now / 1000) - timespan;

  //一分鐘以內(nèi)
  if (milliseconds <= 60) {
    timeSpanStr = '剛剛';
  }
  //大于一分鐘小于一小時(shí)
  else if (60 < milliseconds && milliseconds <= 60 * 60) {
    timeSpanStr = Math.ceil((milliseconds / (60))) + '分鐘前';
  }
  //大于一小時(shí)小于等于一天
  else if (60 * 60 < milliseconds && milliseconds <= 60 * 60 * 24) {
    timeSpanStr = Math.ceil(milliseconds / (60 * 60)) + '小時(shí)前';
  }
  //大于一天小于等于15天
  else if (60 * 60 * 24 < milliseconds && milliseconds <= 60 * 60 * 24 * 30) {
    timeSpanStr = Math.ceil(milliseconds / (60 * 60 * 24)) + '天前';
  }
  //大于一個(gè)月小于一年
  else if (60 * 60 * 24 * 30 < milliseconds && milliseconds <= 60 * 60 * 24 * 30 * 12){
    timeSpanStr = Math.ceil(milliseconds / (60 * 60 * 24 * 30)) + '個(gè)月前';
  }
  //超過一年顯示
  else {
    timeSpanStr = year + '年' + month + '月' + day + '日 ' + hour + ':' + minute;  
  }
  return timeSpanStr;
}