Friday, 14 September 2012

How to prevent activity to being restarted on orientation changed | Prevent activity restart on orientation changed


An Activity is being restarted just because of configuration changes like orientation, screenSize(from API level 10), keyboard hidden etc.
So what you need to do is : declare below line in your manifest file. android:configChanges="keyboard|orientation|keyboardHidden". And if you are using above version of android 2.2(API level 8) you can also declare screenSize parameter too.

Example:

Create a project and replace your code by this code


package com.retainstate;

import android.app.Activity;
import android.app.AlertDialog;
import android.os.Bundle;

public class RetainActivityStateActivity extends Activity {
    /** Called when the activity is first created. */
    @Override
    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.main);
     
        showDialog();
     
    }
 
    private void showDialog()
    {
    AlertDialog.Builder al=new AlertDialog.Builder(this);
        al.setMessage("Hello! Activity will not restart on orientation changing.")
        .setTitle("RetainStateOfActivity").setPositiveButton("OK", null).show();
    }
}

Now let the main.xml as it is

In manifest file


<?xml version="1.0" encoding="utf-8"?>
<manifest xmlns:android="http://schemas.android.com/apk/res/android"
    package="com.retainstate"
    android:versionCode="1"
    android:versionName="1.0" >

    <uses-sdk android:minSdkVersion="8" />

    <application
        android:icon="@drawable/ic_launcher"
        android:label="@string/app_name" >
        <activity
            android:name=".RetainActivityStateActivity"
            android:configChanges="orientation|keyboardHidden"
            android:label="@string/app_name" >
            <intent-filter>
                <action android:name="android.intent.action.MAIN" />

                <category android:name="android.intent.category.LAUNCHER" />
            </intent-filter>
        </activity>
    </application>

</manifest>



Now run the project an alertDialog will show and then change the orientation of emulator by leftCtrl+F11. you dialog will remain stay.



Source Code: download zip.file

6 comments:

  1. This comment has been removed by the author.

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  2. Al-Bashir Ahmad, you can now download complete project. See at the bottom of the tutorial.

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