How prevent calling oncreate method by system when rotation screen happenes? - android

Hi stackoverflow friends. I have an player music and I call in oncreate playSong(id)(id is index of an array which has a path music in that index of array.But there is this problem that when rotates Screen then songs over and over plays from first index in array. I guess becuase oncreate method is called after each time event rotation. Also I want my app prevent from rotation becuse may be this event have bad effect in others activity.too,
How I can fix these type of issues?


You can use
setRequestedOrientation(ActivityInfo.SCREEN_ORIENTATION_LANDSCAPE);
or
setRequestedOrientation(ActivityInfo.SCREEN_ORIENTATION_PORTRAIT);
to lock the orientation. Because as you mentioned, the onCreate is called everytime the screen rotates.
But you have to call it before the setContentView(R.layout.main)
Could look like this:
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setRequestedOrientation(ActivityInfo.SCREEN_ORIENTATION_LANDSCAPE);
setContentView(R.layout.main);
}


you can do like this android:configChanges="orientation|keyboardHidden|screenSize"
hope it will help you
add it to manifest as follows as an example
<application
android:icon="#drawable/ic_launcher"
android:label="#string/app_name"
android:theme="#style/AppTheme" >
<activity
android:name=".MainActivity"
android:label="#string/title_activity_main"
android:configChanges="orientation|screenSize|keyboardHidden">
<intent-filter>
<action android:name="android.intent.action.MAIN" />
<category android:name="android.intent.category.LAUNCHER" />
</intent-filter>
</activity>
</application>


You could add android:configChanges="orientation" to Activity tag on AndroidManifest.xml. Try it.


You could add android:configChanges="orientation|screenSize" to Activity tag on AndroidManifest.xml. It will helpful.

Related

Up navigation goes to main activity

I have the following Androidmanifest file
<application
android:allowBackup="true"
android:icon="#mipmap/ic_launcher"
android:label="#string/app_name"
android:theme="#style/AppTheme" >
<activity
android:name=".MainActivity"
android:label="#string/app_name" >
<intent-filter>
<action android:name="android.intent.action.MAIN" />
<category android:name="android.intent.category.LAUNCHER" />
</intent-filter>
</activity>
<activity
android:name=".First"
android:label="#string/title_activity_first"
android:parentActivityName=".MainActivity" >
<meta-data
android:name="android.support.PARENT_ACTIVITY"
android:value="android.anoop.com.myapplication.MainActivity" />
</activity>
<activity
android:name=".Second"
android:label="#string/title_activity_second"
android:parentActivityName=".First" >
<meta-data
android:name="android.support.PARENT_ACTIVITY"
android:value="android.anoop.com.myapplication.First" />
</activity>
</application>
In main activity's onCreate method i have the following code to launch Second activity
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
Intent intent1=new Intent(this,Second.class);
startActivity(intent1);
}
Other than that every other activities code is what android studio provide as default. But when i press up button from the Second activity it goes directly to main activity and not to the First activity. I know there are alternate solutions for this problem but i just want to know why the up navigation is behaving like this.I am new to android so i may not be understanding something really simple. Any help will be appreciated. Thank you.

If you are using calling SecondActivity in onCreate of FirstActivity, then it goes to SecondActivity. But think about it, when do an Activity actually starts?
It starts after you call onCreate, then onStart , then onResume and then your Actiivity finally starts running. In your case, you are not allowing to go further onCreate, and hence FirstActivity has never even started. And thats why when you go back in navigation it jumps to the previously opened Activity, i.e., MainActivity.
I hope this clears your answer! For reference see the Lificycle of an Activity in this link.

Because FirstActivity is not started or Created. You are calling Second directly from Main Activity. As there is no any First Activity available in application's stack how Second Activity goes to parent Activity First? It will goes to Main Activity as Its the only Activity remain in stack.

How to change orientation to portrait in Fragment Class - Android

My application is in Landscape mode .. I'm trying to change the Fragment in Portrait view ..
Used the below code to rotate from landscape to portrait ..
getActivity().setRequestedOrientation(ActivityInfo.SCREEN_ORIENTATION_PORTRAIT);
But the Fragment "onCreate" and "onCreateView" called twice ..
Can anyone please advice on implement Portrait View in Fragment class ? Or advice to how to avoid calling the onCreateView twice ?

In the Manifest file your activity should adds,
"android:configChanges="keyboardHidden|orientation|screenSize"
For example,
<activity
android:name=".MainActivity"
android:configChanges="keyboardHidden|orientation|screenSize"
android:label="#string/app_name"
android:screenOrientation="landscape" >
<intent-filter>
<action android:name="android.intent.action.MAIN" />
<category android:name="android.intent.category.LAUNCHER" />
</intent-filter>
</activity>
Specifically you should add "screenSize" in the Android manifest file. So that your Fragment "onCreate" and "onCreateView" won't be called twice.

Override setRetainInstance. This should solve your problem

Android activity Restarts When orientation changes

My app seems to restart when it detects an orientation change. Well not really.
I only have portrait orientation enabled though.
In log cat I can see that my app is still doing calculations, but my progress dialog disappears.
What is going on?
In my manifest file this is my activity.
<activity
android:name=".xxxActivity"
android:label="#string/app_name"
android:configChanges="orientation"
android:screenOrientation="portrait">
<intent-filter>
<action android:name="android.intent.action.MAIN" />
<category android:name="android.intent.category.LAUNCHER" />
</intent-filter>
</activity>

Is there a specific reason why you're listening for the orientation change with android:configChanges="orientation"?
If not, remove that and I suspect your problem will go away.
add this right after the super call
setRequestedOrientation(ActivityInfo.SCREEN_ORIENTATION_PORTRAIT);

Better to change configChanges to
android:configChanges="orientation|keyboardHidden"
I guess, that activity is restarted, because you forgot to add onConfigurationChanged(Configuration) method in your activity.
http://developer.android.com/reference/android/app/Activity.html#onConfigurationChanged(android.content.res.Configuration)
It can be empty but shold be in the activity.
Also android:screenOrientation="portrait" is not needed.

How is application orientation (landscape or portrait) locked?

I have tried to freeze orientation using:
setRequestedOrientation(ActivityInfo.SCREEN_ORIENTATION_PORTRAIT);
Although the display stays in portrait orientation, the activity is still recreated. Any ideas how to solve this?
How can the orientation of the application be locked such that the activity is not recreated on orientation change?

First, don't use setRequestedOrientation() if you can avoid it. Use the android:screenOrientation attribute in your <activity> manifest element instead.
Second, you will also need android:configChanges="keyboardHidden|orientation" in your <activity> manifest element to prevent the destroy/recreate cycle.

A more specific example of the activity section of the AndroidManifest.xml for portrait orientation:
<activity
android:name=".MainActivity"
android:label="#string/app_name"
android:screenOrientation="portrait"
android:configChanges="keyboardHidden|orientation|screenSize">
<intent-filter>
<action android:name="android.intent.action.MAIN" />
<category android:name="android.intent.category.LAUNCHER" />
</intent-filter>
</activity>
Where android:screenOrientation sets the initial orientation and android:configChanges voids the events that triggers the corresponding lifecycle methods on screen changes.

Try this:
1.- Set the desired screen orientation in your AndroidManifest.xml
android:screenOrientation="portrait|landscape"
It should look like this:
<application
android:allowBackup="true"
android:icon="~icon path~"
android:label="~name~"
android:supportsRtl="true"
android:screenOrientation="portrait"
android:theme="#style/AppTheme">
</application>
2.- Add this to your onCreate void(or wherever you want) in your java Activity File(Example: "MainActivity.java"):
super.setRequestedOrientation(ActivityInfo.SCREEN_ORIENTATION_LOCKED);
It should look like this:
protected void onCreate(Bundle savedInstanceState) {
super.setRequestedOrientation(ActivityInfo.SCREEN_ORIENTATION_LOCKED);}
Now the screen wont move even if the Screen Rotation is on in the Device.

The best solution is to use the saved instance.
If you are locking the the screen orientation then it means you are forcing the user to use the app according to constraints set by you. So always use onSaveInstanceState. Read this link: http://developer.android.com/training/basics/activity-lifecycle/recreating.html

Prevent screen rotation on Android

I have one of my activities which I would like to prevent from rotating because I'm starting an AsyncTask, and screen rotation makes it restart.
Is there a way to tell this activity "DO NOT ROTATE the screen even if the user is shaking his phone like mad"?

Add
android:screenOrientation="portrait"
or
android:screenOrientation="landscape"
to the <activity> element/s in
the manifest and you're done.

You can follow the logic below to prevent auto rotate screen while your AsyncTask is running:
Store your current screen orientation inside your activity using getRequestedOrientation().
Disable auto screen orientation using setRequestedOrientation(ActivityInfo.SCREEN_ORIENTATION_NOSENSOR).
Run/execute your AsyncTask.
At the end of your AsyncTask restore your previous orientation status using setRequestedOrientation(oldOrientation).
Please note that there are several ways to access Activity (which runs on UI thread) properties inside an AsyncTask. You can implement your AsyncTask as an inner class or you can use message Handler that poke your Activiy class.

The easiest way I found to do this was to put
this.setRequestedOrientation(ActivityInfo.SCREEN_ORIENTATION_PORTRAIT);
within onCreate, just after
setContentView(R.layout.activity_main);
so...
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
this.setRequestedOrientation(ActivityInfo.SCREEN_ORIENTATION_PORTRAIT);
}

In your Manifest file, for each Activity that you want to lock the screen rotation add: if you want to lock it in horizontal mode:
<activity
...
...
android:screenOrientation="landscape">
or if you want to lock it in vertical mode:
<activity
...
...
android:screenOrientation="portrait">

Rather than going into the AndroidManifest, you could just do this:
screenOrientation = getResources().getConfiguration().orientation;
getActivity().setRequestedOrientation(ActivityInfo.SCREEN_ORIENTATION_LOCKED);
... AsyncTask
screenOrientation = getResources().getConfiguration().orientation;
#Override
protected void onPostExecute(String things) {
context.setRequestedOrientation(PlayListFragment.screenOrientation);
or
context.setRequestedOrientation(ActivityInfo.SCREEN_ORIENTATION_FULL_SENSOR);
}
The only drawback here is that it requires API level 18 or higher. So basically this is the tip of the spear.

Activity.java
#Override
public void onConfigurationChanged(Configuration newConfig) {
try {
super.onConfigurationChanged(newConfig);
if (this.getResources().getConfiguration().orientation == Configuration.ORIENTATION_LANDSCAPE) {
// land
} else if (this.getResources().getConfiguration().orientation == Configuration.ORIENTATION_PORTRAIT) {
// port
}
} catch (Exception ex) {
}
AndroidManifest.xml
<application android:icon="#drawable/icon" android:label="#string/app_name">
<activity android:name="QRCodeActivity" android:label="#string/app_name"
android:screenOrientation="landscape" >
<intent-filter>
<action android:name="android.intent.action.MAIN" />
<category android:name="android.intent.category.LAUNCHER" />
</intent-filter>
</activity>
</application>

User "portrait" in your AndroidManifest.xml file might seem like a good solution. But it forces certain devices (that work best in landscape) to go into portrait, not getting the proper orientation. On the latest Android version, you will get wearing an error. So my suggestion it's better to use "nosensor".
<activity
...
...
android:screenOrientation="nosensor">

Add the following to your AndroidManifest.xml
[ app > src > main > AndroidManifest.xml ]
<activity android:name=".MainActivity"
android:configChanges="orientation"
android:screenOrientation="portrait"/>
Example:
<?xml version="1.0" encoding="utf-8"?>
<manifest xmlns:android="http://schemas.android.com/apk/res/android"
package="xxx.zzzzzz.yyyyy">
<uses-permission android:name="A-PERMISSION" />
<application>
<activity android:name=".MainActivity"
android:screenOrientation="portrait"
android:configChanges="orientation">
</activity>
</application>
</manifest>

The following attribute on the ACTIVITY in AndroidManifest.xml is all you need:
android:configChanges="orientation"
So, the full activity node would be:
<activity android:name="Activity1"
android:icon="#drawable/icon"
android:label="App Name"
android:excludeFromRecents="true"
android:configChanges="orientation">
<intent-filter>
<action android:name="android.intent.action.MAIN"/>
<category android:name="android.intent.category.LAUNCHER"/>
</intent-filter>
</activity>

Add:
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setRequestedOrientation(ActivityInfo.SCREEN_ORIENTATION_NOSENSOR);
...
...
...
}

Prevent Screen Rotation just add this following line in your Manifests.
<activity
android:name=".YourActivity"
android:screenOrientation="portrait" />
This works for me.

android:screenOrientation="portrait"
on application tag <application
and
<activity
...
...
android:screenOrientation="locked">

If you are using Android Developer Tools (ADT) and Eclipse
you can go to your AndroidManifest.xml --> Application tab --> go down and select your activity. Finally, select your preferred orientation.
You can select one of the many options.

You have to add the following code in the manifest.xml file.
The activity for which it should not rotate, in that activity add this element
android:screenOrientation="portrait"
Then it will not rotate.

You can try This way
<?xml version="1.0" encoding="utf-8"?>
<manifest xmlns:android="http://schemas.android.com/apk/res/android"
package="com.itclanbd.spaceusers">
<uses-permission android:name="android.permission.INTERNET" />
<uses-permission android:name="android.permission.ACCESS_NETWORK_STATE"/>
<application
android:allowBackup="true"
android:icon="#mipmap/ic_launcher"
android:label="#string/app_name"
android:roundIcon="#mipmap/ic_launcher_round"
android:supportsRtl="true"
android:theme="#style/AppTheme">
<activity android:name=".Login_Activity"
android:screenOrientation="portrait">
<intent-filter>
<action android:name="android.intent.action.MAIN" />
<category android:name="android.intent.category.LAUNCHER" />
</intent-filter>
</activity>
</application>

Use AsyncTaskLoader to keep your data safe even if the activity changes, instead of using AsyncTask that is a better way to build apps than preventing screen rotation.

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