Mass Destruction Android

Create a simple Android Counter Clicker App

2011-12-20T06:01:00.000-08:00

Hello my friends! Today I will show you how to create a simple counter clicker app for android. The counter clicker is use for count the number of something such as people in concert, cars on the road, etc. This app is easy to create and you can improve your better user interface by yourself. Then, here we go!

First, start eclipse and create a new android project named "counterClicker" and set it to Android 2.2 or API level 8. Next, set the package to "my.test.counter"

Next, open /res/layout/main.xml and edit code like this: (You can enlarge this picture by clicking on it.)

Attention: Oh! my friends!! I forget to change the button text. So, in this below xml code, change the first button (id:button2) from "android:text="Button"" to "android:text="Count"" and the second button (id:button1) from "android:text="Button"" to "android:text="Clear"".

Next, open CounterClickerActivity.java and edit the code:

(look at This Tutorial to find how to add sound to the project with MediaPlayer object)

package my.test.counter;

import android.app.Activity;

import android.media.MediaPlayer;

import android.os.Bundle;

import android.view.View;

import android.widget.Button;

import android.widget.TextView;

public class CounterClickerActivity extends Activity {

private TextView txt1, txt2, txt3, txt4;

private Button btnCount, btnClear;

private int i1,i2,i3,i4;

private MediaPlayer mp;

/** Called when the activity is first created. */

@Override

public void onCreate(Bundle savedInstanceState) {

super.onCreate(savedInstanceState);

setContentView(R.layout.main);

txt1 = (TextView) findViewById(R.id.txt1);

txt2 = (TextView) findViewById(R.id.txt2);

txt3 = (TextView) findViewById(R.id.txt3);

txt4 = (TextView) findViewById(R.id.txt4);

btnCount = (Button) findViewById(R.id.button2);

btnCount.setOnClickListener(new View.OnClickListener() {

@Override

public void onClick(View v) {

// TODO Auto-generated method stub

countingNumber();

}

});

btnClear = (Button) findViewById(R.id.button1);

btnClear.setOnClickListener(new View.OnClickListener() {

@Override

public void onClick(View v) {

// TODO Auto-generated method stub

clearingNumber();

}

});

}

private void countingNumber() {

if(mp != null) mp.release();

try {

mp = MediaPlayer.create(this, R.raw.stapler);

mp.start();

} catch (Exception e) {

// TODO: handle exception

e.printStackTrace();

}

if(!(i1==9 && i2==9 && i3==9 && i4==9))i4++;

if(i4>9) {i3++;i4=0;}

if(i3>9) {i2++;i3=0;}

if(i2>9) {i1++;i2=0;}

txt4.setText((i4%10)+"");

txt3.setText((i3%10)+"");

txt2.setText((i2%10)+"");

txt1.setText((i1%10)+"");

}

private void clearingNumber() {

if(mp != null) mp.release();

try {

mp = MediaPlayer.create(this, R.raw.stapler);

mp.start();

} catch (Exception e) {

// TODO: handle exception

e.printStackTrace();

}

i1=0;i2=0;i3=0;i4=0;

txt1.setText(i1+"");

txt2.setText(i2+"");

txt3.setText(i3+"");

txt4.setText(i4+"");

}

OK!!! It's done! Now, run the project and test it. Click on Count Button to increase the number and Clear Button to reset the counter. Have fun!

-vyppN-

Create Your Beyond First Android App (Part 2)

2011-12-19T23:49:00.000-08:00

Hello again! Welcome to part 2 of this tutorial. Now, we will learn about Connecting UI control, Intent, Thread, and MediaPlayer

1. Connect UI to Code

If you want to take control with your Button, TextView, EditText, etc. You can use this instantiate:

Object UI name = (Object UI)findViewById(resource);

example:

Button myButton = (Button)findViewById(R.id.button1);

The example means that when you want to connect an UI component. You must create an Object to connect with your UI base on your component type. From the example: I want to connect button1 to code. So, I create a Button object named myButton that refers to the button1.

Note: You can explore the resource name in /gen/your package/R.java (Click on the triangle)

Look for the code from part1, I use Button to create Intent to navigate to another activity and run a new Thread to play sound at the same time.

btnCon = (Button)findViewById(R.id.btnCon);

btnCon.setOnClickListener(new View.OnClickListener() {

@Override

public void onClick(View v) {

// TODO Auto-generated method stub

}

});

I call the method setOnClickListener() from Button object and set listener to detect clicking for my btnCon button and then eclipse does auto implement onClick() method for me to take control the button.

2. Intent

Intent is the Navigator between two Activities. When Intent started, it stops current activity and calls new activity to display. When back button pressed it stops and destroys the new activity and restarts the previous activity to show again.

From part one when button was clicked:

Intent i = new Intent(getApplicationContext(),HelloAgain.class);

startActivity(i);

This will create an Intent name i and navigate to HelloAgain.class but it’s not fired yet then I use method startActivity(i) to fire the activity i to start HelloAgain Activity

3.Thread

At the same time with 2. I create a new Thread to play a sound. Thread is the thing that run method or make method works. In Java the method main() was run by main thread, but we can create a new thread to parallel run another method at the same time with main() method. This is useful with a method that consume time to wait. Imagine to when you make your breakfast if you cooking like a single thread program you may follow this step -- make toasts -- wait -- boil eggs -- wait -- boil water -- wait -- make coffee, so on. But if you do it in Multi-Thread you can make toasts, boil water and egg in the same time and only wait for make a coffee.

new Thread(new Runnable() {

public void run() {

}

}).start();

To start a new thread I create a runnable thread and call start() method to start a new thread. you can add method in run()

4. Media Player

Like it’s name, Media Player is for play medias. It can play both video and audio but at this time I will only show you only audio playing.

MediaPlayer mp = MediaPlayer.create(getApplicationContext(), R.raw.ring);

Simple to use, I create an Object in MediaPlayer type and name it as mp. Next, I connect it to resource file in /res/raw/ring.mp3 (eclipse will auto generate code to R.raw.ring) and then, my mp is ready to use

mp.start();

To use the mp, just call start() method and the sound will be play, nice and easy!!

note: the code mp.releash(); is use for free resource if mp is already have data. This method uses to free memory for system performance.

This tutorial is end. If you have any question please fell free to ask me. And... yeah.. sorry to my bad English skill...

Create Your Beyond First Android App (Part 1)

2011-12-19T02:13:00.000-08:00

This is my first article about android application development. When you read the phrase "Your first app", you'll say anything in your mind like "I think this must be "Hello World!!" for sure". Don't worry about this. The Hello World was boring me too! So, I'll let get start with a beyond Hello World app. (but it's still Hello Word lol)

In this project we will create an app that contain a Button and a TextView. When you click on the button it'll change to another screen that have a "Hello My Friend!!" text and play some sound. Interesting?

Download Android Sample Code Here

This Article You Will Learn:

How to connect UI to your code
How to use Intent to start new Activity
How to Multithread programming
How to play a sound

Ok, let's move on...

And... Hey! I'll never tell you about how to install the Android SDK or Setting up your work environment because you can find it in various site on the internet just ask Google

Using eclipse. First, Create a new Android Project named "HelloFriend".

I use android platform 2.3.3 (API level 10) and set package name to "com.massdstu.hello"

Next, open main.xml in Package Explorer and edit code like this below then you will get an UI with one TextView and one Button

Next, make a copy of main.xml and rename it to main2.xml in the same folder (/res/layout) and edit code like the below

Next, Create a class named "HelloAgain.java" and edit code like the below:

This project has more than one activity. So, we must add activity to AndroidManifest.xml

Ok! it's nearly done, first, create a folder name it as "raw" under "/res" folder and download this sound and put it in raw folder.

Then, open HelloFriendActivity.java and edit the code:

package com.massdstu.hello;

import android.app.Activity;

import android.content.Intent;

import android.media.MediaPlayer;

import android.os.Bundle;

import android.view.View;

import android.widget.Button;

public class HellofriendActivity extends Activity {

/** Called when the activity is first created. */

Button btnCon;

MediaPlayer mp;

@Override

public void onCreate(Bundle savedInstanceState) {

super.onCreate(savedInstanceState);

setContentView(R.layout.main);

btnCon = (Button)findViewById(R.id.btnCon);

btnCon.setOnClickListener(new View.OnClickListener() {

@Override

public void onClick(View v) {

// TODO Auto-generated method stub

if (mp != null)

mp.release();

new Thread(new Runnable() {

public void run() {

try {

mp = MediaPlayer.create(getApplicationContext(),R.raw.ring);

mp.start();

} catch (Exception e) {

e.printStackTrace();

}

}).start();

Intent i = new Intent(getApplicationContext(),HelloAgain.class);

startActivity(i);

}

});

}

Yeah!! It's done!!! Then, let's run this application by press Run button or command + Fn + Shift+ F11 key (in OSX). While application run you'll see text "Hello World" and a continue button. If you click on the button, you'll here a ring sound and it'll bring you to the second screen that have a text "Hello My Friends".

This is The first part of the project. In the second part I'll explain you about What you are coding in this app. See you in next part.

- vyppN-