how to detect orientation of android device?

问题

Is it possible simple to detect current orientation of android device, without programming a listener and handling the position matrix? In my app I want only to know current orientation - vertical or horizontal - at the moment. However I don't want to listen to events of axiometry or other events.

回答1:

Use the getRotation method:

Display display = ((WindowManager) context.getSystemService(Context.WINDOW_SERVICE)).getDefaultDisplay();
int rotation = display.getRotation();

From the documentation:

Returns the rotation of the screen from its "natural" orientation. The returned value may be Surface.ROTATION_0 (no rotation), Surface.ROTATION_90, Surface.ROTATION_180, or Surface.ROTATION_270. For example, if a device has a naturally tall screen, and the user has turned it on its side to go into a landscape orientation, the value returned here may be either Surface.ROTATION_90 or Surface.ROTATION_270 depending on the direction it was turned. The angle is the rotation of the drawn graphics on the screen, which is the opposite direction of the physical rotation of the device. For example, if the device is rotated 90 degrees counter-clockwise, to compensate rendering will be rotated by 90 degrees clockwise and thus the returned value here will be Surface.ROTATION_90.

Keep in mind that getRotation was introduced from Android 2.2. Use getOrientation if your target are older devices.

回答2:

You can also use:

getResources().getConfiguration().orientation == Configuration.ORIENTATION_LANDSCAPE

回答3:

I think the safest and easiest way is to add a tag for some element of your activity in XML. For example, set the viewpager's tag to "portrait" in the portrait layout and set it to "landscape" in in landscape. Then in your oncreate check for that tag like so:

if(mViewpager.getTag().equals("portrait"))
  // is in portrait
else
  // is in landscape

回答4:

You just need to know the height and the width of your canvas... your surface... your monitor... etc.

maybe you can get it with :

if (canvas.getHeight()>canvas.getWidth() ) {
//portrait
}
else
{
//landscape
}

回答5:

You could make an extension function from the code above:

fun AppCompatActivity.getRotation(): Int{
    val display = (baseContext.getSystemService(Context.WINDOW_SERVICE) as WindowManager).defaultDisplay
    val rotation = display.rotation
    when(rotation){
        Surface.ROTATION_90 -> return R.integer.LANDSCAPE
        Surface.ROTATION_270 -> return R.integer.LANDSCAPE
        Surface.ROTATION_180 -> return R.integer.PORTRAIT
        Surface.ROTATION_0 -> return R.integer.PORTRAIT
        else ->
            return R.integer.PORTRAIT
    }
}

In your resource directory create a constants.xml file with the following contents:

<?xml version="1.0" encoding="utf-8"?>
<resources>
    <integer name="LANDSCAPE">0</integer>
    <integer name="PORTRAIT">1</integer>
</resources>

You code is then as easy as (e.g. vertical / horizontal layout for a Recyclerview in a Fragment:

val a  = activity as AppCompatActivity
        val orientation = a.getRotation()
        when (orientation){
            R.integer.PORTRAIT -> rv.layoutManager = LinearLayoutManager(activity, RecyclerView.VERTICAL,false)
            R.integer.LANDSCAPE -> rv.layoutManager = LinearLayoutManager(activity, RecyclerView.HORIZONTAL,false)
        }

回答6:

This may not be relevant, but if by chance you need to know this because you want to lock the device into its’ current orientation you can toggle between the following two lines of code.

setRequestedOrientation(ActivityInfo.SCREEN_ORIENTATION_FULL_SENSOR);
setRequestedOrientation(ActivityInfo.SCREEN_ORIENTATION_LOCKED);

来源：https://stackoverflow.com/questions/5112118/how-to-detect-orientation-of-android-device

标签

android

orientation