获取屏幕方向

function orientationChange(){ 
switch(window.orientation) { 
case 0: // Portrait 
case 180: // Upside-down Portrait 
// Javascript to setup Portrait view 
break; 
case -90: // Landscape: turned 90 degrees counter-clockwise 
case 90: // Landscape: turned 90 degrees clockwise 
// Javascript to steup Landscape view 
break; 
} 
} 
window.addEventListener("onorientationchange" in window ? "orientationchange" : "resize", orientationChange, false);