/**
 * 禁止浏览器缩放ctrl + 滚轮/+ —
 */
function stopZoom() {
  let zoomText = {
    '_75': () => {
      setZoom(0.75)
    },
    '_80': () => {
      setZoom(0.8)
    },
    '_90': () => {
      setZoom(0.9)
    },
    '_100': () => {
      setZoom(1)
    },
    '_110': () => {
      setZoom(1.1)
    },
    '_125': () => {
      setZoom(1.25)
    },
  }

  document.body.addEventListener('keydown', function (e) {
    if (e.ctrlKey) {
      let text = getZoom();
      (text < 75 || text > 125) && (text = 100);
      zoomText['_' + text]();
    }
  })
}
function setZoom (value) {
  document.body.style.zoom = value;
}
/**
 * 获取浏览器缩放百分比
 */
 function getZoom() {
  var ratio = 0,
      screen = window.screen,
      ua = navigator.userAgent.toLowerCase();

  if (window.devicePixelRatio !== undefined) {
    ratio = window.devicePixelRatio;
  }
  else if (~ua.indexOf('msie')) {
    if (screen.deviceXDPI && screen.logicalXDPI) {
      ratio = screen.deviceXDPI / screen.logicalXDPI;
    }
  }
  else if (window.outerWidth !== undefined && window.innerWidth !== undefined) {
    ratio = window.outerWidth / window.innerWidth;
  }

  if (ratio) {
    ratio = Math.round(ratio * 100);
  }
  return ratio;
}