My 1st Android application Basics

First Activity
-------------------


<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="fill_parent"
    android:layout_height="fill_parent"
    android:orientation="vertical"
    tools:context=".Firstact" >
    <TextView
        android:layout_width="fill_parent"
        android:layout_height="wrap_content"
        android:text="@string/txt"
        />

    <EditText
        android:layout_width="fill_parent"
        android:layout_height="wrap_content"
        android:hint="@string/txt_val"
        android:id="@+id/txt1"
        />

    <Button
        android:id="@+id/click_button"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:text="@string/sub" />

</LinearLayout>


Java Code
----------------

package com.example;

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

public class Firstact extends Activity {
Button bn;
EditText et;
Bundle bundle;
int requestCode;
    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_firstact);
        bn=(Button) findViewById(R.id.click_button);
        et=(EditText) findViewById(R.id.txt1);
        requestCode=1;
        bn.setOnClickListener(new OnClickListener() {
@Override
public void onClick(View arg0) {
// TODO Auto-generated method stub
Intent intent=new Intent("com.example.Second"); /* creating intent object */
bundle=new Bundle(); /* bundle for passing valu*/
bundle.putString("msg",et.getText().toString());
intent.putExtras(bundle);
startActivityForResult(intent, requestCode);
}
});
    }

    @Override
    public boolean onCreateOptionsMenu(Menu menu) {
        // Inflate the menu; this adds items to the action bar if it is present.
        getMenuInflater().inflate(R.menu.activity_firstact, menu);
        return true;
    }
 
    public void onActivityResult(int rc,int resultCode,Intent data)/* validating data and request from second page*/
    {
    if(rc==requestCode)
    {
    if(resultCode==RESULT_OK)
    {
    et.setText(data.getData().toString());
    }
    }
    }
 
}

This is basic application it only shows how to pass a value from 1st page(main activity) to second page(2nd activity) and in reverse.

Second Activity
--------------------

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:layout_width="fill_parent"
    android:layout_height="fill_parent"
    android:orientation="vertical" >
<TextView
    android:layout_width="fill_parent"
    android:layout_height="wrap_content"
    android:text="@string/msg"
    />
<EditText
    android:layout_width="fill_parent"
    android:layout_height="wrap_content"
    android:hint="@string/txt_val"
    android:id="@+id/txt2"
    />
<Button
    android:layout_width="wrap_content"
    android:layout_height="wrap_content"
    android:text="@string/sub"
    android:id="@+id/b2"
    />
</LinearLayout>



Java Code
---------------


package com.example;

import android.app.Activity;
import android.content.Intent;
import android.net.Uri;
import android.os.Bundle;
import android.view.View;
import android.view.View.OnClickListener;
import android.widget.Button;
import android.widget.EditText;

public class Second extends Activity{
Button bn1;
EditText txt;
Bundle bundle;
@Override
protected void onCreate(Bundle savedInstanceState) {
// TODO Auto-generated method stub
super.onCreate(savedInstanceState);
setContentView(R.layout.second_act);
bn1=(Button) findViewById(R.id.b2);
txt=(EditText) findViewById(R.id.txt2);
bundle=getIntent().getExtras();
txt.setHint(bundle.getString("msg"));
bn1.setOnClickListener(new OnClickListener() {
@Override
public void onClick(View arg0) {
// TODO Auto-generated method stub
Intent data=new Intent();
data.setData(Uri.parse(txt.getText().toString()));
setResult(RESULT_OK,data);
finish();
}
});
}
}