HTML5-javascript屏幕旋转事件：onorientationchange

屏幕旋转事件：onorientationchange

添加屏幕旋转事件侦听，可随时发现屏幕旋转状态（左旋、右旋还是没旋）

判断屏幕是否旋转

function orientationChange() {

    switch(window.orientation) {

    　　case 0: 

            alert("肖像模式 0,screen-width: " + screen.width + "; screen-height:" + screen.height);

            break;

    　　case -90: 

            alert("左旋 -90,screen-width: " + screen.width + "; screen-height:" + screen.height);

            break;

    　　case 90:   

            alert("右旋 90,screen-width: " + screen.width + "; screen-height:" + screen.height);

            break;

    　　case 180:   

        　　alert("风景模式 180,screen-width: " + screen.width + "; screen-height:" + screen.height);

        　　break;

    };

};

// 添加事件监听

addEventListener('load', function(){

    orientationChange();

    window.onorientationchange = orientationChange;

});