Navigation between Activities

An Activity is nothing but a screen in an app. For example the Gmap application the screen which displayed the map is nothing but an activity. There will be situations where in you need to traverse from one screen to another. In this post we get to know the simplest way to traverse between activities.

Given below are the steps to achieve this -

1) Define the second activity in the android manifest Table.

2) Create 2 Layouts called Default_Activity and Second_Activity with button in each of them, where in you will traverse from Default_Activity screen to Second Activity.

3) Create 2 java classes for each activity where you will define the action to be done on click of button in each activity.

Now that we got the things that need to be done lets look start coding the same

First Create a new Android Project by clicking on the File and traversing to the New option in the menu. In this case you can use normal Android 2.3 instead of Google Android 2.3 since we don’t use any of the google API’s.

1) Defining Second Activity in Android Manifest Table –

Open the Android Manifest Table and add the following code which will define the second activity.

The android Manifest Table will look like below

2) Creating the 2 layouts –

Go to res folder and click on the Layout folder and a new xml file which will be your second activity.

Create the 2 activity using the graphical layout as shown in the images below.

3) Defining Java classes –

a)  Default_Activity class –

Instantiate the Button class as shown below

Button Act1=(Button) findViewById(R.id.button1);

Then write the code to move to the second activity by using the OnClick function wherein  you create an Intent which instructs the application to go to the second activity.

public void onClick(View view) {

Intent def_intent=new Intent(view.getContext(),Second_Activity.class);

startActivityForResult(def_intent,0); }

Finally your Default_Activity class will look like this.

b) Second_Activity –

Create the onCreate function and set the view to Second2activity as shown below

setContentView(R.layout.second2activity);

Create a new Button which will end the app and return to the default activity screen and in the onClick function use the code below

public void onClick(View v) {

//creating a new intent                                                        

Intent sec_intent=new Intent();                                      

//set the result and return to the default_activity Screen

setResult(RESULT_OK,sec_intent);

//End the Activity

finish();

The Second_Activity will look like the screen shot shown below.

Now that we are done with the coding, lets see if it really works as desired. Right Click on the project and say Run as Android Application.

The initial screen will be the one as shown below, click on the ‘Move to other Activity Button’

On clicking the button you should come to screen 2 as shown below. 

If you again click on the button ‘Congrats you have come to the Second Activity’ it should take you back to the Default Activity Screen.

Woohoooooo you have learnt how to create an activity, in the next post I will let you know how to pass parameters / data between activities. Till then Adios!!!!!!