Skip to main content

Android - The check box creation and event handler mechanism

 This is simple example for creating check box in android application. I have created the new android project and I have modified the main.xml file present in the layout folder with following code.
 Here I have just drag and drooped the check box control and I have changed the text value as "The Checkbox is unchecked". Now I am going to add the on change listener for this check box. I have changed the main java file and this is my code.

import android.app.Activity;
import android.os.Bundle;
import android.widget.CheckBox;
import android.widget.CompoundButton;
import android.widget.CompoundButton.OnCheckedChangeListener;

public class BasicInputsActivity extends Activity implements OnCheckedChangeListener{
    /** Called when the activity is first created. */
       CheckBox checkBox1;
    @Override
    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.main);
        checkBox1 = (CheckBox)findViewById(R.id.checkBox1);
        checkBox1.setOnCheckedChangeListener(this);
    }

       @Override
       public void onCheckedChanged(CompoundButton buttonView, boolean isChecked) {
              if(checkBox1.isChecked()) {
                     checkBox1.setText("The Checkbox is checked");
              }
              else {
                     checkBox1.setText("The Checkbox is unchecked");
              }
       }
   
}
 For adding on change listener for Check box I have implemented the OnCheckChangeListener interface as well as I have override the onCheckedChanged method. Finally I have checked whether the check box is created or not based on this condition I have changed the text value of check box using setText function. If you preview this application you can able to get the result like this.


 The setChecked() and toggle() are other important methods of CheckBox .

Labels:

Comments

Post a Comment

Popular posts from this blog

Ext JS 4 – Creating web page using Ext.container.Viewport class and region propery

The Ext.container.Viewport is used for creating general web page and region property is used for splitting web page into different parts. Ext.container.Viewport is a specialized container represents the viewable area of the application (the browser area). It render itself to the document body, there is no need for providing renderTo property and it automatically sizes itself to size of the browser viewport. The viewport also re-size the child elements based on view area(based on browser width and height). The default layout of the viewport is border layout and we can customize this property according to our requirements. The viewport does not provide any scrolling. If necessary, the child elements(generally panels) within viewport needs to provide a scroll feature by using autoScroll property. See the below example for better understanding. This is Home.js file placed into app/view folder. Ext.define('MyApp.view.Home', { extend : 'Ext.container.Viewport&#
4 comments
Read more

Getting servlet init parameter that is defined in web.xml

1. Create a new dynamic web project using eclipse. 2. Create a one new servlet and include the following code. package com.controller ; import java.io.IOException; import javax.servlet .ServletConfig; import javax.servlet .ServletException; import javax.servlet .annotation.WebServlet; import javax.servlet .http.HttpServlet; import javax.servlet .http.HttpServletRequest; import javax.servlet .http.HttpServletResponse; @ WebServlet ( "/LoginController" ) public class LoginController extends HttpServlet {                 private static final long serialVersionUID = 1L;                 public LoginController() {         super ();     }     protected void doPost( HttpServletRequest request, HttpServletResponse response) throws ServletException , IOException {                                 ServletConfig config = getServletConfig ();                                 System.out.println( "Init parameter user nam
1 comment
Read more

Simple Login Application Using Spring MVC and Hibernate – Part 1

 I hope developers working in web application development might hear about MVC architecture. Almost all technologies provide support for MVC based web application development, but the success is based on many factors like reusable of the code, maintenance of the code, future adaption of the code, etc..,  The success of the Spring MVC is “ Open for extension and closed for modification ” principle. Using Spring MVC the developers can easily develop MVC based web application. We don’t need any steep learning curve at the same time we need to know the basics of spring framework and MVC architecture. The Spring MVC consists of following important components. 1. Dispatcher servlet 2. Controller 3. View Resolver 4. Model Spring MVC - Overview  The overall architecture of Spring MVC is shown here.  1. When “Dispatcher Servlet” gets any request from client, it finds the corresponding mapped controller for the request and just dispatches the request to the corresponding contro
60 comments
Read more