js里获取屏幕尺寸

function reSize()
{
 var showWidth = document.body.clientWidth;
 showWidth = (showWidth - 6)/2;
 document.getElementById("apple").style.width = showWidth;
 document.getElementById("android").style.width = showWidth;
 document.getElementById("setState").style.width = showWidth;
 document.getElementById("shareHeart").style.width = showWidth;
}