How to create Multiple Screens in Android Applications : Android API 15, Eclipse

In this post I will show you the way I found to have multiple screens in your Android Application. To do this I used Eclipse as my IDE. And I used Android API 15 as my development environment.
When you create a new Android project in Eclipse, you can find that it will auto generate a main.xml file and the particular .java file for handling that. Lets see a screen shot of that.

When you insert some code and run it, it will show a single screen like this,

So this way you can develop your single screen android applications. Until you need single screen to develop a application it will be not a problem. But when you want to have several screens in your app and you need to navigate though them. You are in trouble. So I found out a way to do this. So I thought to share it with you guys.
To have multiple screen, first of all you have to create XML files for those screens. So in your projects res/layout folder create a new android XML file. then it will generate a new screen. Here is the way I created, Lets see a screen shot :

 Here In my project I have created three screens. In the main.xml file It will show the well come screen. In there I have put a button. When the user push that button then user will brought to the second screen which is named as selection_screen.xml. To do that we have to have a .java file for the selection_screen.xml. So I have created a java file for that. Here it is :

So how we use this xml files java files to achieve our task of switch between screens? As you know each and every screen in Android is a activity. So first of all we have to introduce our new screen as a activity to the Android app. To do that you have to edit the AndroidManifest.xml.

To add a new activity, you have to add this element as child element of application,


<?xml version="1.0" encoding="utf-8"?>
 <activity
            android:name=".You Java Files Name"
            android:label="Any name you want show as the title of the activity window." &gt;
</activity>

Here is my Example,


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


    <uses-sdk android:minSdkVersion="15" />


    <application
android:icon="@drawable/ic_launcher"
        android:label="Travel Ceylon" >
        <activity
            android:name=".Travel_CeylonActivity"
            android:label="Travel Ceylon" >
            <intent-filter>
                <action android:name="android.intent.action.MAIN" />


                <category android:name="android.intent.category.LAUNCHER" />
            </intent-filter>
        </activity>
        <activity
            android:name=".SelectionActivity"
            android:label="Travel Ceylon Selection" >
        </activity>
        <activity
            android:name=".Important_place_addActivity"
            android:label="Add Importatn place to Travel Ceylon" >
        </activity>
    </application>


</manifest>




So after adding this you can see the R.java file in you application is generated. With your new elements in your new screens. So next thing is to add some code to those java files to navigate through screens. Here is the code you should add to your onCreate() method. It will show the new screen when  you press a button.


Button b = (Button) findViewById(R.id.button1); // Here the R.id.button1 is the button form you design
           b.setOnClickListener(new View.OnClickListener() {
           public void onClick(View arg0) {
           Intent i = new Intent(Current Java Files Name.this, The name of the next java files which will be executed on the button click.class);
           startActivity(i);
           }
});

Here is my example. It will guide user from Travel_CeylonActivity to SelectionActivity when user push the button Enter Travel Ceylon.



package travelceylon.client;




import android.app.Activity;
import android.content.Intent;
import android.os.Bundle;
import android.view.View;
import android.widget.Button;


public class Travel_CeylonActivity extends Activity {
    /** Called when the activity is first created. */
    @Override
    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.main);
        Button b = (Button) findViewById(R.id.button1);
        b.setOnClickListener(new View.OnClickListener() {
           public void onClick(View arg0) {
           Intent i = new Intent(Travel_CeylonActivity.this, SelectionActivity.class);
           startActivity(i);
           }
        });
    }
}

After doing this I have edited the SelectionActivity.java like this, It also have two buttons and I have code it for go to another screen when I push a button.


package travelceylon.client;


import android.app.Activity;
import android.content.Intent;
import android.os.Bundle;
import android.view.View;
import android.widget.Button;




public class SelectionActivity extends Activity {
public void onCreate(Bundle icicle)
  {
     super.onCreate(icicle);
     setContentView(R.layout.selection_screen);
     Button b = (Button) findViewById(R.id.button3);
       b.setOnClickListener(new View.OnClickListener() {
          public void onClick(View arg0) {
          Intent i = new Intent(SelectionActivity.this, Important_place_addActivity.class);
          startActivity(i);
          }
       });
  }
}

So after that you can run your application. You can see that when you press the button it will take you from screen 1 to screen 2. So like wise customize this approach to your app. I thought this will help you. Please leave your comments.