var $horizontal = $('.horizontal_screen') ; //可自定義橫屏模式提示樣式
var $document = $(document) ;
var preventDefault = function(e) {
e.preventDefault();
};
var touchstart = function(e) {
$document.on('touchstart touchmove', preventDefault);
};
var touchend = function(e) {
$document.off('touchstart touchmove', preventDefault);
};

function listener(type){
if('add' == type){
//豎屏模式
$horizontal.addClass('hide');
$document.off('touchstart', touchstart);
$document.off('touchend', touchend);
}else{
//橫屏模式
$horizontal.removeClass('hide');
$document.on('touchstart', touchstart);
$document.on('touchend', touchend);
}
}
function orientationChange(){
switch(window.orientation) {
//豎屏模式
case 0:
case 180:
listener('add');
break;
//橫屏模式
case -90:
case 90:
listener('remove');
break;
}
}

$(window).on("onorientationchange" in window ? "orientationchange" : "resize", orientationChange);

$document.ready(function(){
//以橫屏模式進入界面，提示只支持豎屏
if(window.orientation == 90 || window.orientation == -90){
listener('remove');
}
});