Getting started with android/first program in android

What all stuffs you need to run your first android app??

Before getting started, make your computer ready…

1. Download and install JDK

2. Download and setup Eclipse IDE

3. Download Android SDK and then expand the content of the zip file into a folder

4. Install the ADT plug-in in Eclipse

• Start Eclipse, then select Help > Install New Software....

• Click Add, in the top-right corner.

• In the Add Repository dialog that appears, enter "ADT Plugin" for the Name and the following URL for the Location:

                                "https://dl-ssl.google.com/android/eclipse/"

• Click OK

• In the Available Software dialog, select the checkbox next to Developer Tools and click Next.

• In the next window, you'll see a list of the tools to be downloaded. Click Next.

• Read and accept the license agreements, then click Finish.

• When the installation completes, restart Eclipse

[If you are not patient enough to do all these tasks, then the best method is to copy eclipse software which have already an adt plug-in and paste that copy on your machine…..simple…right?? :) ]

5.Configure Eclipse to point to the Android SDK

• Select Window > Preferences...

• Select Android from the left panel.

• For the SDK Location in the main panel, click Browse... and locate your downloaded SDK directory.

• Click Apply, and then OK.

Installation done, let’s do some code

First create an android project. For that

1. Open package explorer in eclipse, right click on some blank space and choose “New”> “Android Project” 

1. Fill out the form with values fitting your applications purpose... 

As you now have created your first Android Project you will see a bunch of files appear in that new project. (Don’t get panic by seeing all these files…most of them are resource files)

Ok guys, now we can now start coding. Navigate to src folder on your package explorer, then navigate to your package and open .java class. You’ll see some  code like  following

Basic coding are done for you….

Forget about all the code except “setcontentview(R.layout.main)”(At this time only;) ). This method is used to load view of your app.
Now, I am going to create a button in xml,and the button will display some text while clicking on it.

Designing of your application can be done using xml file. Open “res” folder and select layout folder. Double click on main.xml

Just add two lines inside button tag

-->

android:clickable="true"

android:onClick="select"

Save it and again go to .java class. Create a method in ".java" class with the same name that you given in android:onClick of button tag in the xml layout. Then inside the method,write a code to dynamically print a text

(Don't forget to pass object of the class View as parameter. It is very important and will discuss later..)

public void select(View v)

{

TextView textView=new TextView(this);

textView.setText("Hi friends, I did my first application!!!");

setContentView(textView);

}

Full Source code

package com.example; import android.app.Activity; import android.os.Bundle; import android.view.View; import android.widget.TextView; public class FirstProgramActivity extends Activity {     /** Called when the activity is first created. */     @Override     public void onCreate(Bundle savedInstanceState) {         super.onCreate(savedInstanceState);         setContentView(R.layout.main);     }     public void select(View v){       TextView textView=new TextView(this);       textView.setText("Hi friends, I did my first application!!!");       setContentView(textView);     } }

main.xml

<?xml version="1.0" encoding="utf-8"?> <LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"     android:orientation="vertical"     android:layout_width="fill_parent"     android:layout_height="fill_parent"     > <TextView      android:layout_width="fill_parent"     android:layout_height="wrap_content"     android:text="@string/hello"     /> <Button android:text="Button" android:clickable="true" android:onClick="select" android:id="@+id/button1" android:layout_width="wrap_content" android:layout_height="wrap_content"> </Button> </LinearLayout>

 Result

Next

First game in anroid

Activity Lifecycle