Dynamic Checkboxes: Java Code (Cont.)
final LinkedHashMap<String, String>
    alphabet = new LinkedHashMap<String, String>( );

  • HashMap is hashtable based implementation of the Map interface. The HashMap class is roughly equivalent to Hashtable, except that it is unsynchronized and permits nulls.

  • LinkedHashMap differs from HashMap in that it maintains a doubly-linked list running through all of its entries. This linked list defines the iteration ordering, which is normally the order in which keys were inserted into the map (insertion-order).

alphabet.put( "260", ".NET" );
The method put associates the specified value with the specified key in this map. If the map previously contained a mapping for the key, the old value is replaced.

Set<?> set = alphabet.entrySet( );
Returns a Set view of the mappings contained in this map.

Iterator<?> i = set.iterator( );
Returns an iterator over the elements in this set.

while ( i.hasNext( ) ) {
Returns true if the iteration has more elements.

@SuppressWarnings( "rawtypes" )
Indicates that the named compiler warnings should be suppressed in the annotated element.

Map.Entry me = ( Map.Entry ) i.next( );
A map entry is a key-value pair. The method next returns the next element in the iteration.
DynamicCheckbox/app/src/main/java/com/ecs/wenchen/dynamiccheckbox/MainActivity.java
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01package com.ecs.wenchen.dynamiccheckbox;
02 
03import java.util.Iterator;
04import java.util.LinkedHashMap;
05import java.util.Map;
06import java.util.Set;
07 
08import android.app.Activity;
09import android.os.Bundle;
10import android.view.View;
11import android.widget.Button;
12import android.widget.CheckBox;
13import android.widget.LinearLayout;
14import android.widget.TextView;
15import android.widget.EditText;
16import android.graphics.Color;
17 
18public class MainActivity extends Activity {
19  LinearLayout linearBox;
20  CheckBox     checkBox, checkBox1;
21 
22  @Override
23  protected void onCreate( Bundle savedInstanceState ) {
24    super.onCreate( savedInstanceState );
25    setContentView( R.layout.activity_main );
26 
27    linearBox = (LinearLayout) findViewById( R.id.linearBox );
28    final EditText number = (EditText) findViewById( R.id.number );
29    final EditText title  = (EditText) findViewById( R.id.title );
30    final Button   button = (Button)   findViewById( R.id.add );
31 
32    button.setOnClickListener( new View.OnClickListener( ) {
33      public void onClick( View v ) {
34        checkBox1 = new CheckBox( getApplicationContext( ) );
35        checkBox1.setId( Integer.parseInt( number.getText( ).toString( ) ) );
36        checkBox1.setText( title.getText( ).toString( ) );
37        checkBox1.setTextColor( Color.BLACK );
38        checkBox1.setOnClickListener( getOnClickDoSomething( checkBox1 ) );
39        linearBox.addView( checkBox1 );
40      }
41    } );
42 
43    final LinkedHashMap<String, String>
44      alphabet = new LinkedHashMap<String, String>( );
45    alphabet.put( "260", ".NET" );
46    alphabet.put( "370", "Computer Architecture" );
47 
48    Set<?> set = alphabet.entrySet( );
49    // Get an iterator.
50    Iterator<?> i = set.iterator( );
51    // Display elements.
52    while ( i.hasNext( ) ) {
53      @SuppressWarnings( "rawtypes" )
54      Map.Entry me = ( Map.Entry ) i.next( );
55      checkBox     = new CheckBox( this );
56      checkBox.setId( Integer.parseInt( me.getKey( ).toString( ) ) );
57      checkBox.setText( me.getValue( ).toString( ) );
58      checkBox.setOnClickListener( getOnClickDoSomething( checkBox ) );
59      linearBox.addView( checkBox );
60    }
61  }
62 
63  View.OnClickListener getOnClickDoSomething( final Button button ) {
64    return new View.OnClickListener( ) {
65      public void onClick( View v ) {
66        final TextView tvView = (TextView) findViewById( R.id.textView3 );
67        tvView.setText( button.getId( ) + ": " + button.getText( ).toString( ) );
68      }
69    };
70  }
71}




      The other day, my wife asked me to pass her lipstick,    
      but I accidentally passed her a glue stick.    
      She still isn’t talking to me.