LESSON 1: CREATE MY FIRST ANDROID APPLICATION

Task 1: HelloWorld

Step 1 - Open “Android Studio”

Step 2 – Click New -> New Project

Step 3 – Enter “HelloWorld”

Step 4 – Click “Next”

Step 5 – Click “Empty Activity” then click “Next”

Step 6 – Click “Finish”

Step 7 – Write source code in MainActivity.java

package com.example.manchester.helloworld;

import android.support.v7.app.AppCompatActivity;import android.os.Bundle;import android.view.View;import android.widget.Button;import android.widget.TextView;

public class MainActivity extends AppCompatActivity {

TextView txt; Button btn; protected void onCreate(Bundle savedInstanceState) { super.onCreate(savedInstanceState); setContentView(R.layout.activity_main); txt = (TextView)findViewById(R.id.MsgID); btn = (Button)findViewById(R.id.btnClick);

btn.setOnClickListener(new View.OnClickListener() { public void onClick(View v) { txt.setText("New Message / Hello World"); } }); }}

Step 8 – Run & execute the program

Task 2: Calculation

Step 1 – Design Layout

Step 2 – Write code in MainActivity.java

package com.example.manchester.mycalculation;

import android.support.v7.app.AppCompatActivity;import android.os.Bundle;import android.view.View;import android.widget.Button;import android.widget.Switch;import android.widget.TextView;import android.widget.EditText;

public class MainActivity extends AppCompatActivity implements View.OnClickListener{

private Button BtnAdd; private EditText etFirst, etSecond; private TextView etResult;

protected void onCreate(Bundle savedInstanceState) { super.onCreate(savedInstanceState); setContentView(R.layout.activity_main); init(); }

private void init() { BtnAdd = (Button)findViewById(R.id.BtnAdd); etFirst = (EditText)findViewById(R.id.etFirst); etSecond = (EditText)findViewById(R.id.etSecond); etResult = (TextView)findViewById(R.id.etResult);

BtnAdd.setOnClickListener(this);

}

public void onClick(View view) { String num1 = etFirst.getText().toString(); String num2 = etSecond.getText().toString(); switch(view.getId()) { case R.id.BtnAdd: int addition = Integer.parseInt(num1) + Integer.parseInt(num2); etResult.setText(String.valueOf(addition)); break; }

}

}MainActivity.java

Step 3 – Execute android application

Step 4 – Enter first number and second number.