CheckBox

A check box is a specific two states button that can be either checked or unchecked. i've set  a demo login page.In the Activity class, (CheckBoxActivity.java), i have validated the username and password.After successful login,the next screen provides a list of checkboxes to select our accounts and on clicking proceed,another screen (success.xml) will show "Contacts Added Successfully!!!"


For invalid login, it directs to invalid.xml page and on clicking cancel at the login screen,it gets directed to cancel.xml.


main.xml



<?xml version="1.0" encoding="utf-8"?>
<RelativeLayout android:id="@+id/RelativeLayout01"
xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="wrap_content"
android:layout_height="wrap_content">

<TextView android:id="@+id/view01"
android:layout_marginTop="50dip"
android:layout_marginLeft="220dip"
android:text="Welcome User"
android:layout_width="fill_parent"
android:layout_height="wrap_content"
android:layout_centerHorizontal="true">
</TextView>

<TextView android:id="@+id/tv01"
android:layout_marginTop="100dip"
android:layout_marginLeft="50dip"
android:layout_width="fill_parent"
android:layout_height="wrap_content"
android:text="Username ">
</TextView>

<EditText android:id="@+id/et01"
android:layout_marginTop="90dip"
android:layout_marginLeft="130dip"
android:layout_width="160dip"
android:layout_height="50dip">
</EditText>

<TextView android:id="@+id/tv02"
android:layout_marginTop="75dip"
android:layout_marginLeft="50dip"
android:layout_width="fill_parent"
android:layout_below="@id/tv01"
android:layout_height="wrap_content"
android:text="Password ">
</TextView>

<EditText android:id="@+id/et02"
android:layout_marginTop="175dip"
android:layout_marginLeft="130dip"
android:layout_width="160dip"
android:layout_height="50dip"
android:password="true">
</EditText>

<Button android:id="@+id/btn01"
android:layout_below="@id/tv02"
android:layout_marginLeft="50dip"
android:layout_width="115dip"
android:layout_height="50dip"
android:text="Login"
android:layout_marginTop="50dip">
</Button>

<Button android:id="@+id/btn02"
android:layout_below="@id/tv02"
android:layout_marginLeft="200dip"
android:layout_width="115dip"
android:layout_height="50dip"
android:text="Cancel"
android:layout_marginTop="50dip">
</Button>

</RelativeLayout>

check.xml



<?xml version="1.0" encoding="utf-8"?>
<RelativeLayout
  xmlns:android="http://schemas.android.com/apk/res/android"
  android:layout_width="fill_parent"
  android:layout_height="fill_parent">

  <TextView android:id="@+id/Check_tv01"
  android:layout_marginTop="8dip"
  android:layout_width="fill_parent"
  android:layout_height="wrap_content"
  android:text="Select your accounts"
  android:layout_marginLeft="60dip"
  android:textSize="19px"
  android:typeface="serif">

  </TextView>
  <CheckBox android:id="@+id/Check_yahoo"
  android:layout_width="wrap_content"
  android:layout_height="wrap_content"
  android:text="Yahoo"
  android:layout_marginTop="30dip">
  </CheckBox>

  <CheckBox android:id="@+id/Check_msn"
  android:layout_width="wrap_content"
  android:layout_height="wrap_content"
  android:text="MSN Live"
  android:layout_below="@id/Check_yahoo"
  android:layout_marginTop="1dip">
  </CheckBox>

  <CheckBox android:id="@+id/Check_twitter"
  android:layout_width="wrap_content"
  android:layout_height="wrap_content"
  android:text="Twitter"
  android:layout_below="@id/Check_msn"
  android:layout_marginTop="1dip">
  </CheckBox>

  <CheckBox android:id="@+id/Check_gtalk"
  android:layout_width="wrap_content"
  android:layout_height="wrap_content"
  android:text="Google Talk"
  android:layout_below="@id/Check_twitter"
  android:layout_marginTop="1dip">
  </CheckBox>

  <Button android:id="@+id/Check_proceed"
  android:layout_marginLeft="65dip"
  android:layout_width="150dip"
  android:layout_height="40dip"
  android:text="Proceed"
  android:layout_below="@id/Check_gtalk"
  android:layout_marginTop="10dip"/>
  </RelativeLayout>

CheckBoxActivity.java



package com.adsample;

import android.app.Activity;
import android.os.Bundle;
import android.view.View;
import android.view.View.OnClickListener;
import android.widget.Button;
import android.widget.EditText;
import android.widget.TextView;


public class CheckBoxActivity extends Activity {
    /** Called when the activity is first created. */
    @Override
    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.main);
   
        final EditText etUsername;
        final EditText etPassword;
        final Button btnLogin;
        final Button btnCancel;
        final TextView lblResult;
          
        etUsername=(EditText)findViewById(R.id.et01);       //to get a handle for the edit texts and buttons
        etPassword=(EditText)findViewById(R.id.et02);
        btnLogin=(Button)findViewById(R.id.btn01);
        btnCancel=(Button)findViewById(R.id.btn02);
     
          btnLogin.setOnClickListener(new OnClickListener(){      //to define on click of login button,what
          public void onClick(View v){                                          //event should occur
        String username=etUsername.getText().toString();
        String password=etPassword.getText().toString();

        if(username.equals("guest")&& password.equals("guest")){     //validating username and pswd
        setContentView(R.layout.check);
         Button btnProceed=(Button)findViewById(R.id.Check_proceed);
        btnProceed.setOnClickListener(new OnClickListener(){
        public void onClick(View v1){
        setContentView(R.layout.success);                           //sets success.xml  on successful login
        }
        });
        }
        else{
        setContentView(R.layout.invalid);                             //sets invalid.xml on invalid login
        }
        }

        });
        btnCancel.setOnClickListener(new OnClickListener(){
       
public void onClick(View v) {
setContentView(R.layout.cancel_login); //sets cancel_login on pressing cancel button.
}
        });
    }
}


success.xml



<?xml version="1.0" encoding="utf-8"?>
<RelativeLayout
  xmlns:android="http://schemas.android.com/apk/res/android"
  android:layout_width="fill_parent"
  android:layout_height="fill_parent">

  <TextView android:id="@+id/success_tv01"
  android:layout_width="fill_parent"
  android:layout_height="wrap_content"
  android:typeface="serif"
  android:textSize="18px"
  android:text="Contacts Added"
  android:layout_marginTop="80dip"
  android:layout_marginLeft="75dip">
  </TextView>

  <TextView android:id="@+id/success_tv02"
  android:layout_width="fill_parent"
  android:layout_height="wrap_content"
  android:typeface="serif"
  android:textSize="18px"
  android:text="Successfully!!!"
  android:layout_marginTop="110dip"
  android:layout_marginLeft="75dip">
  </TextView>
</RelativeLayout>

invalid.xml

<?xml version="1.0" encoding="utf-8"?>

<RelativeLayout

  xmlns:android="http://schemas.android.com/apk/res/android"

  android:layout_width="fill_parent"

  android:layout_height="fill_parent">

  <TextView android:id="@+id/success_tv01"

  android:layout_width="fill_parent"

  android:layout_height="wrap_content"

  android:typeface="serif"

  android:textSize="14px"

  android:text="Invalid Credentials!!!"

  android:layout_marginTop="20dip"

  android:layout_marginLeft="35dip">

  </TextView>

</RelativeLayout>

cancel.xml

<?xml version="1.0" encoding="utf-8"?>

<RelativeLayout

  xmlns:android="http://schemas.android.com/apk/res/android"

  android:layout_width="fill_parent"

  android:layout_height="fill_parent">

  <TextView android:id="@+id/success_tv01"

  android:layout_width="fill_parent"

  android:layout_height="wrap_content"

  android:typeface="serif"

  android:textSize="14px"

  android:text="Session Expired!!!"

  android:layout_marginTop="20dip"

  android:layout_marginLeft="35dip">

  </TextView>

</RelativeLayout>

Outputs

Android 2.2 with API 8 was used.

AlertBox

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:id="@+id/btn1"
    android:layout_width="150dip"
    android:layout_height="wrap_content"
    android:text="Click Me">
    </Button>
</LinearLayout>


AlertActivity.java



package com.adsample;

import android.app.Activity;
import android.app.AlertDialog;
import android.content.DialogInterface;
import android.os.Bundle;
import android.view.View;
import android.view.View.OnClickListener;
import android.widget.Button;
import android.widget.Toast;

public class AlertActivity extends Activity implements OnClickListener {
    /** Called when the activity is first created. */
    @Override
    public void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
        setContentView(R.layout.main);
        Button btnview=(Button) (findViewById(R.id.btn1));
        btnview.setOnClickListener(this);
       
        }

public void onClick(View v) {
AlertDialog.Builder alertbox = new AlertDialog.Builder(this);
alertbox.setMessage("Hello User");
alertbox.setPositiveButton("+ve", new DialogInterface.OnClickListener() {

            public void onClick(DialogInterface arg0, int arg1) {
           
                Toast.makeText(getApplicationContext(), "+vebutton clicked", Toast.LENGTH_LONG).show();
                onPause();
                }
        });
alertbox.setNeutralButton("neutral", new DialogInterface.OnClickListener() {

         
            public void onClick(DialogInterface arg0, int arg1) {
                Toast.makeText(getApplicationContext(), "Neutral button clicked", Toast.LENGTH_LONG).show();
                onPause();
            }
        });
alertbox.setNegativeButton("-ve", new DialogInterface.OnClickListener() {

         
            public void onClick(DialogInterface arg0, int arg1) {
                Toast.makeText(getApplicationContext(), "-ve button clicked", Toast.LENGTH_LONG).show();
                onPause();
            }
        });

alertbox.show();
}
}

Android 2.2 with Min SDK Version :8 was used.