List in J2ME

J2ME Canvas List Example will explain you, how to create list of items. In this example we are going to create a simple list of text, that will show the selected item on the same screen.

List in J2ME

     

J2ME Canvas List Example will explain you, how to create list of items. In this example we are going to create a simple list of text, that will show the selected item on the same screen. In the example you can see that we have created a class and then a constructor of the same class. In the constructor we defined the list and added some items into it..

Syntax for creating a list

  public CanvasListExample() {
  canvas = new CanvasList();
  list = new List("Employee List", Choice.IMPLICIT);
  show = new Command("Show", Command.OK, 1);
  list.append("Miss. Anusmita"null);
  list.append("Miss. Neelam"null);
  list.append("Mr. Sandeep"null);
  list.append("Mr. Suman"null);
  list.append("Mr. Saurabh"null);
  list.addCommand(show);
  display = Display.getDisplay(this);
  }

You can add any number of elements into it using list.append ()

The simple list application will look like as follow..

List in J2ME

 

 

Source Code of CanvasListExample.java

import javax.microedition.midlet.*;
import javax.microedition.lcdui.*;

public class CanvasListExample extends MIDlet implements CommandListener{
  private Display display;
  private CanvasList canvas;
  private List list;
  private Command show;

  public CanvasListExample() {
  canvas = new CanvasList();
  list = new List("Employee List", Choice.IMPLICIT);
  show = new Command("Show", Command.OK, 1);
  list.append("Miss. Anusmita", null);
  list.append("Miss. Neelam", null);
  list.append("Mr. Sandeep", null);
  list.append("Mr. Suman", null);
  list.append("Mr. Saurabh", null);
  list.addCommand(show);
  display = Display.getDisplay(this);
  }

  public void startApp(){
  list.setCommandListener(this);
  display.setCurrent(list);
  }

  public void pauseApp() {}

  public void destroyApp(boolean unconditional){
  notifyDestroyed();
  }

  public void commandAction(Command c, Displayable d){
  String label = c.getLabel();
  if(label.equals("Show")){
  display.setCurrent(canvas);
  }
  }
  class CanvasList extends Canvas implements CommandListener{
  private Image image;
  private Command back;

  public CanvasList(){
  back = new Command ( "Back", Command.BACK, 1);
  addCommand (back);
  setCommandListener (this);
  }

  public void paint(Graphics g){
  int width = getWidth();
  int height = getHeight();
  String str = list.getString(list.getSelectedIndex());

  g.setColor(0, 0, 255);
  g.drawString(str, width/2, height/2, Graphics.HCENTER | Graphics.TOP);
  }

  public void commandAction(Command c, Displayable d){
  String label = c.getLabel();  
  if(label.equals("Back")){
  display.setCurrent(list);
  }
  }
  }
}

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