获取浏览器可视窗口高度

 

getClientHeight () {
    let clientHeight = 0
    if (document.body.clientHeight && document.documentElement.clientHeight) {
      clientHeight = (document.body.clientHeight < document.documentElement.clientHeight) ? document.body.clientHeight : document.documentElement.clientHeight
    } else {
      clientHeight = (document.body.clientHeight > document.documentElement.clientHeight) ? document.body.clientHeight : document.documentElement.clientHeight
    }
    return clientHeight
  }