Using color in Android, by Java code

In last article, Using color in Android, by XML, described how to define color in XML file. Here, changing color using Java code will be described.



Keep using the main.xml and mycolor.xml

Modify Java code

package com.exercise.AndroidColor;

import android.app.Activity;
import android.os.Bundle;
import android.view.View;
import android.widget.Button;
import android.widget.LinearLayout;

public class AndroidColor extends Activity {
   /** Called when the activity is first created. */
   @Override
   public void onCreate(Bundle savedInstanceState) {
       super.onCreate(savedInstanceState);
       setContentView(R.layout.main);
      
       final LinearLayout backGround = (LinearLayout)findViewById(R.id.background);
       Button whiteButton = (Button)findViewById(R.id.whitebutton);
       Button redButton = (Button)findViewById(R.id.redbutton);
       Button greenButton = (Button)findViewById(R.id.greenbutton);
       Button blueButton = (Button)findViewById(R.id.bluebutton);
      
       whiteButton.setOnClickListener(new Button.OnClickListener(){
   @Override
   public void onClick(View v) {
    // TODO Auto-generated method stub
    backGround.setBackgroundResource(android.R.color.white);
   }});
      
       redButton.setOnClickListener(new Button.OnClickListener(){
   @Override
   public void onClick(View v) {
    // TODO Auto-generated method stub
    backGround.setBackgroundColor(0xff000000 + 0xff0000);
   }});
      
       greenButton.setOnClickListener(new Button.OnClickListener(){
   @Override
   public void onClick(View v) {
    // TODO Auto-generated method stub
    backGround.setBackgroundResource(R.color.green);
   }});
      
       blueButton.setOnClickListener(new Button.OnClickListener(){
   @Override
   public void onClick(View v) {
    // TODO Auto-generated method stub
    backGround.setBackgroundResource(R.color.blue);
   }});
   }
}

Download the files.