1. CMPE419 Mobile Application Development
Asst.Prof.Dr.Ahmet Ünveren
SPRING
Computer Engineering Department
CMPE419 AU

2. Adding New Page and Button, EditText, TextView

3. How to add a new page to the existing project?
package com.example.buttonw; import android.app.Activity; import android.os.Bundle; public class ButtonMainActivity extends Activity protected void onCreate(Bundle savedInstanceState) { super.onCreate(savedInstanceState); setContentView(R.layout.activity_button_main); }
ButtonMainActivity.java

4. <RelativeLayout xmlns:android="http://schemas. android
<RelativeLayout xmlns:android=" xmlns:tools=" android:layout_width="match_parent" android:layout_height="match_parent" tools:context="${relativePackage}.${activityClass}" > </RelativeLayout>
Activity_button_main.xml

5. For creating a new page : right click to layout directory and select from New-Activity Empty Activity

8. AndroidManifest.xml <?xml version="1.0" encoding="utf-8"?>
<manifest xmlns:android="
package="com.example.buttonw"
android:versionCode="1"
android:versionName="1.0" >
<uses-sdk
android:minSdkVersion="8"
android:targetSdkVersion="21" />
<application
android:allowBackup="true"
>
<activity
android:name=".ButtonMainActivity"
>
<intent-filter>
<action android:name="android.intent.action.MAIN" />
<category android:name="android.intent.category.LAUNCHER" />
</intent-filter>
</activity>
</application>
</manifest>

9. For the new activity we have to add the following code to the AndroidManifest.xml file:
android:name=".NewActivity"
>
<intent-filter>
<action android:name="android.intent.action.NEW" />
<category android:name="android.intent.category.DEFAULT" />
</intent-filter>
</activity>

11. Button, EditView and TextView
TextView  is a label for displaying text
EditView  is a textbox for entering a text
Lets add a Button, an EditView and a TextView to the main activity.

13. Now lets enter a text and display it after pressing a button.
For this we have to use Java code and create appropreate objects.

17. <RelativeLayout xmlns:android="http://schemas. android
xmlns:tools="
android:layout_width="match_parent"
android:layout_height="match_parent"
tools:context="${relativePackage}.${activityClass}" >
<TextView
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_centerHorizontal="true"
android:layout_marginTop="62dp"
android:text="TextView" />
<EditText
android:layout_alignParentTop="true"
android:layout_marginTop="78dp"
android:ems="10" >
<requestFocus />
</EditText>
<Button
android:layout_marginTop="60dp"
android:text="Button" />
</RelativeLayout>

18. package com.example.buttonw;
import android.app.Activity;
import android.os.Bundle;
import android.view.View;
import android.widget.Button;
import android.widget.EditText;
import android.widget.TextView;
public class ButtonMainActivity extends Activity {
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_button_main);
final TextView show=(TextView)findViewById(R.id.textView1);
show.setText("");
final EditText all=(EditText)findViewById(R.id.editText1);
Button b=(Button)findViewById(R.id.button1);
b.setText("Display");
b.setOnClickListener(new View.OnClickListener() {
public void onClick(View v) {
// TODO Auto-generated method stub
show.setText(all.getText()); }
});

19. How to jump new activity? Create a New Button
Use this button to jump to new acctivity.
Button bb=(Button)findViewById(R.id.button2);
bb.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View v) {
// TODO Auto-generated method stub
startActivity(new Intent("android.intent.action.NEW")); }
});

20. Example protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
show=(TextView) findViewById(R.id.TextView1);
Inputtext=(EditText) findViewById(R.id.editText1);
Display=(Button) findViewById(R.id.button1);
View.OnClickListener eventh=new View.OnClickListener() {
@Override
public void onClick(View v) {
// TODO Auto-generated method stub
a=a+1;
show.setText(Inputtext.getText()+"Button Pressed"+a); } };
Display.setOnClickListener(eventh);

21. Example Button a,c; TextView b; @Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
b = (TextView) findViewById(R.id.textView1);
a = (Button) findViewById(R.id.button1);
c= (Button) findViewById(R.id.button2);
// create click listener
OnClickListener oclBtnOk = new OnClickListener() {
public void onClick(View v) {
// change text of the TextView
switch (v.getId()){
case R.id.button1:
b.setText("Button 1 clicked");
break;
case R.id.button2:
//b.setText("Button 2 clicked");
startActivity(new Intent("android.intent.action.NEW"));
break;} } };
// assign click listener to the OK button (btnOK)
a.setOnClickListener(oclBtnOk);
c.setOnClickListener(oclBtnOk);