Detect change in orientation using javascript

问题

Is it possible to detect change in orientation of the browser on the iPad or Galaxy Tab using javascript? I think it\'s possible using css media queries.

回答1:

UPDATE:

You might want to check out

jQuery mobile orientationchange

or the plain JS one:

window.addEventListener("orientationchange", function() {
  alert(window.orientation);
}, false);

MDN:

window.addEventListener("orientationchange", function() {
    alert("the orientation of the device is now " + screen.orientation.angle);
});

---

Older answer

http://www.nczonline.net/blog/2010/04/06/ipad-web-development-tips/

Safari on the iPad does support the window.orientation property, so if necessary, you can use that to determine if the user is in horizontal or vertical mode. As reminder of this functionality:

window.orientation is 0 when being held vertically
window.orientation is 90 when rotated 90 degrees to the left (horizontal)
window.orientation is -90 when rotated 90 degrees to the right (horizontal)

There is also the orientationchange event that fires on the window object when the device is rotated.

You can also use CSS media queries to determine if the iPad is being held in vertical or horizontal orientation, such as:

<link rel="stylesheet" media="all and (orientation:portrait)" href="portrait.css">
<link rel="stylesheet" media="all and (orientation:landscape)" href="landscape.css">

---

http://www.htmlgoodies.com/beyond/webmaster/toolbox/article.php/3889591/Detect-and-Set-the-iPhone--iPads-Viewport-Orientation-Using-JavaScript-CSS-and-Meta-Tags.htm

<script type="text/javascript">
var updateLayout = function() {
  if (window.innerWidth != currentWidth) {
    currentWidth = window.innerWidth;
    var orient = (currentWidth == 320) ? "profile" : "landscape";
    document.body.setAttribute("orient", orient);
    window.scrollTo(0, 1);
  }
};

iPhone.DomLoad(updateLayout);
setInterval(updateLayout, 400);
</script>

回答2:

You can use the orientationchange event like so:

window.addEventListener('orientationchange', function(){
     /* update layout per new orientation */
});

回答3:

window.orientation is what you're looking for. there's also an onOrientationChange event works for android, iphone and, i'm mostly sure, for ipad

回答4:

Adding to the @mplungjan answer, I found better results using the webkit "native" (I don't really how to called it) event, 'deviceorientation'.

In the Mozilla Developer network they have a good explanation about how to normalize between webkit and Gecko that helped me to solve this problem.

回答5:

You can use mediaMatch to evaluate CSS media queries, e.g.

window
    .matchMedia('(orientation: portrait)')
    .addListener(function (m) {
        if (m.matches) {
            // portrait
        } else {
            // landscape
        }
    });

CSS media query fires before the orientationchange. If you are looking to capture the end of the event (when the rotation has been completed), see mobile viewport height after orientation change.

回答6:

An easy to use snippet :

function doOnOrientationChange()
{
    switch(window.orientation)
    { 
        case -90:
        case 90:
          // alert('landscape');
          $('#portrait').css({display:'none'});
          $('#landscape').css({display:'block'});

          break;
        default:
          // alert('portrait');
          $('#portrait').css({display:'block'});
          $('#landscape').css({display:'none'});
          break;
    }
}

window.addEventListener('orientationchange', doOnOrientationChange);

// First launch
doOnOrientationChange();

回答7:

From "Cross-device, cross-browser portrait-landscape detection"

This is about finding out whether a mobile device is in portrait or landscape mode; you don't need to care about its orientation. For all you know, if you hold your iPad upside down, it's in portrait mode.

$(window).bind("resize", function(){
    screenOrientation = ($(window).width() > $(window).height())? 90 : 0;
});

90 means landscape, 0 means portrait, cross browser, cross device.

The window.onresize event is available everywhere, and it's always fired at the right time; never too early, never too late. As a matter of fact, the size of the screen is always accurate as well.

The JavaScript version would be this, correct me please if I am wrong.

  function getScreenOrientation() {
    screenOrientation = window.outerWidth > window.outerHeight ? 90 : 0;
    console.log("screenOrientation = " + screenOrientation);
  }
  window.addEventListener("resize", function(event) {
    getScreenOrientation();
  });
  getScreenOrientation();

来源：https://stackoverflow.com/questions/5498934/detect-change-in-orientation-using-javascript