Most apps change their presentation between […] Most apps change their presentation between […] The way you restore state can vary between different Activities and between Activities and Fragments. How to dynamically change android mobile phone device screen orientation Landscape,Portrait on button click. Purchasing Items from Google Play on Your Android Phone. A nifty app that demonstrates the phone’s accelerometer in action is the game Labyrinth. [caption id=”attachment_3243" align=”aligncenter” width=”500"], With the configChanges flag the same layout will be used in landscape and portrait unless you manually change it[/caption], [caption id=”attachment_3245" align=”aligncenter” width=”500"], Without the configChanges flag you can use different layouts in landscape and portrait[/caption]. In the AsyncTask callbacks (onPreExecute, onProgressUpdate, onPostExecute and onCancelled), you should make sure the listener isn’t null then trigger the appropriate callback on the listener and let it handle the rest. If you use a retained Fragment to host your AsyncTask, you can avoid ever having to restart your tasks. There are two radio buttons in above example. Step 1 − Create a new project in Android Studio, go to File ⇒ New Project and fill all required details to create a new project. When it destroys your Activities and Fragments it will end up creating new instances of them which will wipe out all of your member variables. The Android operating system restarts the … 1. One of the most common “solutions” to dealing with orientation changes is to not deal with them. Android does this so that your application can reload resources based on the new configuration. How to Change the Orientation of Your Android Phone. When you need a reference to your Fragment you can call FragmentManager.findFragmentByTag(String) and pass in the tag you used when adding the Fragment. This method will help us to change the screen orientation after start activity using MainActivity.java file. There are a few dangerous things that could happen with improperly handled AsyncTasks: memory leaks and crashes. To demonstrate how the phone orients itself, rotate the device to the left or right. An Activity’s onRestoreInstanceState is called after onStart and before onResume. In the AndroidManifest.xml file, lock the activity orientation to portrait. If you are using an ArrayList of a model object to populate your ListView, then one option is to ensure your model object implements Serializable and in onSaveInstanceState, place it in the Bundle through putSerializable. When Android destroys your Activity or Fragment because of an orientation change (or any other configuration change), it will not destroy any AsyncTasks that you started. For watching movies, landscape mode is the best. Android phones feature a gizmo called an accelerometer. 1. To demonstrate how the phone orients itself, rotate the device to the left or right. See below for examples of how and where you can restore state in a Fragment: In the example above, we restored state in two different places. To lock the screen orientation change of any screen (activity) of your android application makes your activity display only in one mode i.e. The most important aspect of handling orientation changes is saving state. It covers how to work with the Android resource system to automatically load resources for a particular device orientation as well as how to programmatically handle orientation changes. This example demonstrates how do I detect orientation change in layout in android. What’s On the Home Screen of an Android Phone? If you need to obtain a reference to the Fragment you can do so through the FragmentManager using a tag. While it may seem a bit tedious to implement, handling orientation changes properly provides you with several benefits: you will be able to easily use alternate layouts in portrait and landscape orientations, and you will be able to handle many exceptional states such as low memory situations and interruptions from incoming phone calls without any extra code. One way to avoid this is to cancel AsyncTasks in your Activity or Fragment’s onDestroy method. You are particularly susceptible to memory leaks if you have an AsyncTask declared as a non-static inner class of an Activity or Fragment because that AsyncTask will implicitly hold a reference to its parent class (in this case the Activity or Fragment) even though it appears as though it doesn’t have this reference.