How to Set Screen Orientation portrait or landscape

Their is 2 ways to set Screen Orientation:

First Way:

In Android manifest file(manifest.xml)just add this to the activity attribute tag for portrait add this

android:screenOrientation="portrait"

For landscape :

android:screenOrientation="landscape"

Second Way:

Using code also we can set  Screen Orientation .

In Activity onCreate() method 

For Landscape:

setRequestedOrientation(ActivityInfo.SCREEN_ORIENTATION_LANDSCAPE);

For  portrait:

setRequestedOrientation(ActivityInfo.SCREEN_ORIENTATION_PORTRAIT);

But you must add these line in OnCreate() and before setContentView(). in your Activity.