Develop Reference

ActionBarActivity can not resolve from popstack

When I use the device's back button to return to my first Activity (MainActivity.java below) from my second (MainActivity2.java below), my first Activity's onCreate() method is called every time, but if I use the ActionBar's back button then my onCreate() method is not called.
MainActivity.java
package exam.mcq.it.intentdemo;
import android.content.Intent;
import android.support.v7.app.ActionBarActivity;
import android.os.Bundle;
import android.view.Menu;
import android.view.MenuItem;
import android.view.View;
import android.widget.Button;
import android.widget.Toast;
public class MainActivity extends ActionBarActivity {
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
Toast.makeText(this,"Create method call",Toast.LENGTH_SHORT).show();
Button btn=(Button)findViewById(R.id.btnClick);
btn.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View v) {
Intent in=new Intent(MainActivity.this,MainActivity2.class);
startActivity(in);
}
});
}
#Override
public boolean onCreateOptionsMenu(Menu menu) {
// Inflate the menu; this adds items to the action bar if it is present.
getMenuInflater().inflate(R.menu.menu_main, menu);
return true;
}
#Override
public boolean onOptionsItemSelected(MenuItem item) {
// Handle action bar item clicks here. The action bar will
// automatically handle clicks on the Home/Up button, so long
// as you specify a parent activity in AndroidManifest.xml.
int id = item.getItemId();
//noinspection SimplifiableIfStatement
if (id == R.id.action_settings) {
return true;
}
return super.onOptionsItemSelected(item);
}
}
MainActivity2.java
package exam.mcq.it.intentdemo;
import android.support.v7.app.ActionBarActivity;
import android.os.Bundle;
import android.view.Menu;
import android.view.MenuItem;
public class MainActivity2 extends ActionBarActivity {
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main_activity2);
getSupportActionBar().setDisplayHomeAsUpEnabled(true);
}
#Override
public boolean onCreateOptionsMenu(Menu menu) {
// Inflate the menu; this adds items to the action bar if it is present.
getMenuInflater().inflate(R.menu.menu_main_activity2, menu);
return true;
}
#Override
public boolean onOptionsItemSelected(MenuItem item) {
// Handle action bar item clicks here. The action bar will
// automatically handle clicks on the Home/Up button, so long
// as you specify a parent activity in AndroidManifest.xml.
int id = item.getItemId();
//noinspection SimplifiableIfStatement
if (id == R.id.action_settings) {
return true;
}
return super.onOptionsItemSelected(item);
}
}
AndroidMainfest.xml
<?xml version="1.0" encoding="utf-8"?>
<manifest xmlns:android="http://schemas.android.com/apk/res/android"
package="exam.mcq.it.intentdemo" >
<application
android:allowBackup="true"
android:icon="#drawable/ic_launcher"
android:label="#string/app_name"
android:theme="#style/AppTheme" >
<activity
android:name=".MainActivity"
android:label="#string/app_name" >
<intent-filter>
<action android:name="android.intent.action.MAIN" />
<category android:name="android.intent.category.LAUNCHER" />
</intent-filter>
</activity>
<activity
android:name=".MainActivity2"
android:label="#string/title_activity_main_activity2"
android:parentActivityName=".MainActivity">
<intent-filter>
<action android:name="exam.mcq.it.MainActivity2" />
<category android:name="android.intent.category.default" />
</intent-filter>
</activity>
</application>
</manifest>

I had the same issue. I used a small hack, not sure if this is the right way to do. I called the onBackPressed() method when the arrow is pressed.
#Override
public boolean onOptionsItemSelected(MenuItem item) {
switch (item.getItemId())
{
case R.id.action_save:
save();
return true;
case android.R.id.home:
//Pressing on up Arrow was calling onCreate of MainActivity
getActivity().onBackPressed();
return true;
}
Your question is not clear so I am assuming you do not want onCreate() to be called when Arrow in actionBar is pressed.

Override onBackPressed () function in the activity. That function will be called when the back press button is used. Also, refer the life cycle of an activity in the docs

Only works in Main Activity?

So I have a code, that's only works in the MainActivity, and I don't know how to make it work, in the second activity.
import android.app.Activity;
import android.content.res.Resources;
import android.support.v7.app.ActionBarActivity;
import android.os.Bundle;
import android.view.Menu;
import android.view.MenuItem;
import android.view.View;
import android.widget.Button;
import android.widget.TextView;
import java.util.Random;
public class MainActivity extends Activity {
private String[] myString;
private static final Random rgenerator = new Random();
#Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
Resources res = getResources();
myString = res.getStringArray(R.array.myArray);
String q = myString[rgenerator.nextInt(myString.length)];
TextView tv = (TextView) findViewById(R.id.textView);
tv.setText(q);
}
#Override
public boolean onCreateOptionsMenu(Menu menu) {
// Inflate the menu; this adds items to the action bar if it is present.
getMenuInflater().inflate(R.menu.menu_main, menu);
return true;
}
public void ButtonOnClick (View v) {
Button button = (Button) v;
setContentView(R.layout.activity_szabaly);
}
#Override
public boolean onOptionsItemSelected(MenuItem item) {
// Handle action bar item clicks here. The action bar will
// automatically handle clicks on the Home/Up button, so long
// as you specify a parent activity in AndroidManifest.xml.
int id = item.getItemId();
//noinspection SimplifiableIfStatement
if (id == R.id.action_settings) {
return true;
}
return super.onOptionsItemSelected(item);
}
}
When I start my app, in the first activity the text is changing(because it's a random text changing code), but when I press the button, that makes me go to the second activity, nothing happens, no action in the second activity.
What am I doing wrong?
My Manifest file
<?xml version="1.0" encoding="utf-8"?>
<manifest xmlns:android="http://schemas.android.com/apk/res/android"
package="com.example.example" >
<application
android:allowBackup="true"
android:icon="#mipmap/ic_launcher"
android:label="#string/app_name"
android:theme="#style/AppTheme" >
<activity
android:name=".MainActivity"
android:label="#string/app_name" >
<intent-filter>
<action android:name="android.intent.action.MAIN" />
<category android:name="android.intent.category.LAUNCHER" />
</intent-filter>
</activity>
<activity
android:name=".Szabaly"
android:label="#string/title_activity_szabaly" >
</activity>
</application>
</manifest>

you add the android:onClick attribute in the layout ? this is bad practice
better implementing View.OnClickListener
public class MainActivity extends Activity {
private String[] myString;
private static final Random rgenerator = new Random();
#Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
Resources res = getResources();
myString = res.getStringArray(R.array.myArray);
String q = myString[rgenerator.nextInt(myString.length)];
TextView tv = (TextView) findViewById(R.id.textView);
tv.setText(q);
//finde button
Button button =(Button)findViewById(R.id.button);
//set OnClickListener
button.setOnClickListener(this);
}
#Override
public void onClick(View v) {
switch (v.getId()) {
case R.id.button:
Intent intent = new Intent(this, Szabaly.class);
startActivity(intent );
break;
}
}
}

You're not actually starting a new activity on your button click. Instead you're just changing your view. This will not be cause to call the onCreate method again.
public void ButtonOnClick (View v) {
Button button = (Button) v;
setContentView(R.layout.activity_szabaly);
}
This code is only changing the view. To start a new activity you'd need to create a new class that extends Activity (just like MainActivity) and register it in the AndroidManifest.xml.
Then you'll be able to start the new activity on click by the following
public void ButtonOnClick (View v) {
Intent i = new Intent(this, NewActivity.class);
startActivity(i);
}
See this question for more detail on starting a new Activity from a button click.

want to send text from one activity to another in android

I have tried to write a program for sending text from main activity to another activity "DisplayMessageActivity". But when I have installed that app in my android mobile, after pressing the button , it crashed with a message "unfortunately app has stopped'"
My different files are as under...(eclipse)
MainActivity.java file...
package com.example.practice3;
import android.content.Intent;
import android.os.Bundle;
import android.support.v4.app.Fragment;
import android.support.v7.app.ActionBarActivity;
import android.view.LayoutInflater;
import android.view.Menu;
import android.view.MenuItem;
import android.view.View;
import android.view.ViewGroup;
import android.widget.EditText;
public class MainActivity extends ActionBarActivity {
public final static String EXTRA_MESSAGE = "com.example.myfirstapp.MESSAGE";
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
if (savedInstanceState == null) {
getSupportFragmentManager().beginTransaction()
.add(R.id.container, new PlaceholderFragment())
.commit();
}
}
#Override
public boolean onCreateOptionsMenu(Menu menu) {
// Inflate the menu; this adds items to the action bar if it is present.
getMenuInflater().inflate(R.menu.main, menu);
return true;
}
#Override
public boolean onOptionsItemSelected(MenuItem item) {
// Handle action bar item clicks here. The action bar will
// automatically handle clicks on the Home/Up button, so long
// as you specify a parent activity in AndroidManifest.xml.
int id = item.getItemId();
if (id == R.id.action_settings) {
return true;
}
return super.onOptionsItemSelected(item);
}
/**
* A placeholder fragment containing a simple view.
*/
public static class PlaceholderFragment extends Fragment {
public PlaceholderFragment() {
}
#Override
public View onCreateView(LayoutInflater inflater, ViewGroup container,
Bundle savedInstanceState) {
View rootView = inflater.inflate(R.layout.fragment_main, container, false);
return rootView;
}
}
public void sendMessage(View view) {
Intent intent = new Intent(this, DisplayMessageActivity.class);
EditText editText = (EditText) findViewById(R.id.edit_message);
String message = editText.getText().toString();
intent.putExtra(EXTRA_MESSAGE, message);
startActivity(intent);
}
}
2.fragment_main.xml file
<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:tools="http://schemas.android.com/tools"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:orientation="horizontal">
<EditText android:id="#+id/edit_message"
android:layout_weight="1"
android:layout_width="0dp"
android:layout_height="wrap_content"
android:hint="#string/edit_message" />
<Button
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:text="#string/button_send"
android:onClick="sendMessage"
/>
</LinearLayout>
DisplayMessageActivity.java file
package com.example.practice3;
import android.content.Intent;
import android.os.Bundle;
import android.support.v4.app.Fragment;
import android.support.v7.app.ActionBarActivity;
import android.view.LayoutInflater;
import android.view.Menu;
import android.view.MenuItem;
import android.view.View;
import android.view.ViewGroup;
import android.widget.TextView;
public class DisplayMessageActivity extends ActionBarActivity {
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_display_message);
Intent intent = getIntent();
String message = intent.getStringExtra(MainActivity.EXTRA_MESSAGE);
// Create the text view
TextView textView = new TextView(this);
textView.setTextSize(40);
textView.setText(message);
// Set the text view as the activity layout
setContentView(textView);
if (savedInstanceState == null) {
getSupportFragmentManager().beginTransaction()
.add(R.id.container, new PlaceholderFragment()).commit();
}
}
#Override
public boolean onCreateOptionsMenu(Menu menu) {
// Inflate the menu; this adds items to the action bar if it is present.
getMenuInflater().inflate(R.menu.display_message, menu);
return true;
}
#Override
public boolean onOptionsItemSelected(MenuItem item) {
// Handle action bar item clicks here. The action bar will
// automatically handle clicks on the Home/Up button, so long
// as you specify a parent activity in AndroidManifest.xml.
int id = item.getItemId();
if (id == R.id.action_settings) {
return true;
}
return super.onOptionsItemSelected(item);
}
/**
* A placeholder fragment containing a simple view.
*/
public static class PlaceholderFragment extends Fragment {
public PlaceholderFragment() {
}
#Override
public View onCreateView(LayoutInflater inflater, ViewGroup container,
Bundle savedInstanceState) {
View rootView = inflater.inflate(R.layout.fragment_display_message,
container, false);
return rootView;
}
}
}
4.fragment_display_message.xml file
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:tools="http://schemas.android.com/tools"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:paddingBottom="#dimen/activity_vertical_margin"
android:paddingLeft="#dimen/activity_horizontal_margin"
android:paddingRight="#dimen/activity_horizontal_margin"
android:paddingTop="#dimen/activity_vertical_margin"
tools:context="com.example.practice3.DisplayMessageActivity$PlaceholderFragment" >
<TextView
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:text="#string/hello_world" />
</RelativeLayout>
5.Strings.xml file
<?xml version="1.0" encoding="utf-8"?>
<resources>
<string name="app_name">My First App</string>
<string name="edit_message">Enter a message</string>
<string name="button_send">Send</string>
<string name="action_settings">Settings</string>
<string name="title_activity_main">MainActivity</string>
<string name="title_activity_display_message">DisplayMessageActivity</string>
<string name="hello_world">Hello world!</string>
</resources>

In DisplayMessageActivity.java file comment out below code.
There is no R.id.container in corresponding xml file.
if (savedInstanceState == null) {
getSupportFragmentManager().beginTransaction()
.add(R.id.container, new PlaceholderFragment()).commit();
}

Have you added your DisplayMessageActivity in the AndroidManifest.xml in the application tag like:
<activity android:label="#string/app_name" android:name=".DisplayMessageActivity"/>

Just check this link, if you copy the code, it will work!
I recommend you create a blank activity instead of an activity with fragment also, it's easier to start using android!
Create an intent where you are going to store the text :
public void sendMessage(View view) {
Intent intent = new Intent(this, DisplayMessageActivity.class);
EditText editText = (EditText) findViewById(R.id.edit_message);
String message = editText.getText().toString();
intent.putExtra(EXTRA_MESSAGE, message);
startActivity(intent);
}
... and here is the onCreate method of the activity you just started :
#Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
// Get the message from the intent
Intent intent = getIntent();
String message = intent.getStringExtra(MainActivity.EXTRA_MESSAGE);
// Create the text view
TextView textView = new TextView(this);
textView.setTextSize(40);
textView.setText(message);
// Set the text view as the activity layout
setContentView(textView);
}

How do I start a new activity from the main activity and display all the elements along with the background?

I am a beginner in Android programming and to learn it I am making a sample calculator example myself using the references on the web, now this is something I want to do. I followed the tutorial "Building you First App" as provided on official Google documentation and I was successful in sparking off a new activity on hitting a button using the Intents class, here is the image of the application at the start -:
but when I hit the enter button, even though I have set the android:background option for the new activity it doesn't set the background to that image, the only thing I get is a blank activity, here is the image -:
here is the code for my MainActivity that starts up when the application starts -
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:tools="http://schemas.android.com/tools"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:orientation="vertical"
android:background="#drawable/math_symbols" >
<Button android:id="#+id/enter_button"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:text="#string/enter_button"
android:onClick="enterCalculator"/>
</LinearLayout>
Here's the code for the second activity that starts when I hit the enter button and this is done using Intents -:
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:tools="http://schemas.android.com/tools"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:orientation="vertical"
android:background="#drawable/calculato_activity_1" >
<RadioGroup android:id="#+id/operation_radio_group"
android:layout_width="fill_parent"
android:layout_height="wrap_content"
android:layout_marginLeft="30dip"
android:orientation="horizontal">
<RadioButton android:id="#+id/sum"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:text="#string/sum">
</RadioButton>
<RadioButton android:id="#+id/difference"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:text="#string/difference">
</RadioButton>
<RadioButton android:id="#+id/multiply"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:text="#string/multiply">
</RadioButton>
</RadioGroup>
</LinearLayout>
no background is displayed above and no views are added to the screen, also here is how I am using Intents in the MainActivity class -:
package com.example.mathcalculator;
import android.support.v7.app.ActionBarActivity;
import android.support.v7.app.ActionBar;
import android.support.v4.app.Fragment;
import android.content.Intent;
import android.os.Bundle;
import android.view.LayoutInflater;
import android.view.Menu;
import android.view.MenuItem;
import android.view.View;
import android.view.ViewGroup;
import android.os.Build;
public class MainActivity extends ActionBarActivity {
// this is the message used to enter the main calculator activity
public static String ENTER_MESSAGE = "com.example.mathcalculator.MainActivity.Message";
// this method is used to enter the actual calculator screen
public void enterCalculator(View view){
// we create an Intent to carry over the data from the button and enter the CalculatorActivity1
Intent intent = new Intent(this, CalculatorActivity1.class);
// put the key-value pair into the intent
intent.putExtra(ENTER_MESSAGE, "ENTER");
// start the new activity with the intent as the input which carries over the message bundle
startActivity(intent);
}
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
if (savedInstanceState == null) {
getSupportFragmentManager().beginTransaction()
.add(R.id.container, new PlaceholderFragment()).commit();
}
}
#Override
public boolean onCreateOptionsMenu(Menu menu) {
// Inflate the menu; this adds items to the action bar if it is present.
getMenuInflater().inflate(R.menu.main, menu);
return true;
}
#Override
public boolean onOptionsItemSelected(MenuItem item) {
// Handle action bar item clicks here. The action bar will
// automatically handle clicks on the Home/Up button, so long
// as you specify a parent activity in AndroidManifest.xml.
int id = item.getItemId();
if (id == R.id.action_settings) {
return true;
}
return super.onOptionsItemSelected(item);
}
/**
* A placeholder fragment containing a simple view.
*/
public static class PlaceholderFragment extends Fragment {
public PlaceholderFragment() {
}
#Override
public View onCreateView(LayoutInflater inflater, ViewGroup container,
Bundle savedInstanceState) {
View rootView = inflater.inflate(R.layout.fragment_main, container,
false);
return rootView;
}
}
}
and here is the code for the CalculatorActivity1 class -:
package com.example.mathcalculator;
import android.support.v7.app.ActionBarActivity;
import android.support.v4.app.Fragment;
import android.os.Bundle;
import android.view.LayoutInflater;
import android.view.Menu;
import android.view.MenuItem;
import android.view.View;
import android.view.ViewGroup;
public class CalculatorActivity1 extends ActionBarActivity {
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
}
#Override
public boolean onCreateOptionsMenu(Menu menu) {
// Inflate the menu; this adds items to the action bar if it is present.
getMenuInflater().inflate(R.menu.calculator_activity1, menu);
return true;
}
#Override
public boolean onOptionsItemSelected(MenuItem item) {
// Handle action bar item clicks here. The action bar will
// automatically handle clicks on the Home/Up button, so long
// as you specify a parent activity in AndroidManifest.xml.
int id = item.getItemId();
if (id == R.id.action_settings) {
return true;
}
return super.onOptionsItemSelected(item);
}
/**
* A placeholder fragment containing a simple view.
*/
public static class PlaceholderFragment extends Fragment {
public PlaceholderFragment() {
}
#Override
public View onCreateView(LayoutInflater inflater, ViewGroup container,
Bundle savedInstanceState) {
View rootView = inflater.inflate(
R.layout.fragment_calculator_activity1, container, false);
return rootView;
}
}
}

You need to set a content view for your activity. It is already done in the sample app activity, so inside the oncreate method of your MainActivity, you can see: setContentView(R.layout.activity_main);
It is setting the activity_main layout to the MainActivity content view.
So you need to do this to the CalculatorActivity1 too, under the super.onCreate(savedInstanceState);
You can find your second layout name in the res/layout folder.

You are not commiting the change in fragment. After the setContentView(R.layout.xml_file); inside onCreate you should have this:
if (savedInstanceState == null) {
getSupportFragmentManager().beginTransaction()
.add(R.id.container, new PlaceholderFragment()).commit();
}

You missed to set background in the second activity xml.
android:background="#drawable/math_symbols"
Bind the xml layout to the second activity CalculatorActivity1:
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.<xmlName>);
}

Clicking a Button and Opening a new Activity [duplicate]

This question already has an answer here:
Android adding new xml and class
(1 answer)
Closed 8 years ago.
This could be perceived as a silly question, but I am very new to Android.
I am making an app and I have added an info Activity, I have an info button on my main page and want to go to the info activity when I click it..
I'm actually not sure how to go about it.
this is the xml for the Button:
<Button
android:id="#+id/button2"
style="?android:attr/buttonStyleSmall"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_alignParentBottom="true"
android:layout_alignParentLeft="true"
android:background="#FFFFFF"
android:text="#string/info_btn" />
Do I add the code in the main activity, the intro activity or the xml?
This is my main activity
package ie.gmit.project;
import android.support.v7.app.ActionBarActivity;
import android.support.v7.app.ActionBar;
import android.support.v4.app.Fragment;
import android.content.Intent;
import android.net.Uri;
import android.os.Bundle;
import android.view.LayoutInflater;
import android.view.Menu;
import android.view.MenuItem;
import android.view.View;
import android.view.ViewGroup;
import android.widget.Button;
import android.os.Build;
public class MainActivity extends ActionBarActivity {
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
if (savedInstanceState == null) {
getSupportFragmentManager().beginTransaction()
.add(R.id.container, new PlaceholderFragment())
.commit();
}
}
public void openSite(View v){
Uri uri = Uri.parse("http://gmitsu.ie/clubssocs/directory.html");
Intent intent = new Intent(Intent.ACTION_VIEW, uri);
startActivity(intent);
}
#Override
public boolean onCreateOptionsMenu(Menu menu) {
// Inflate the menu; this adds items to the action bar if it is present.
getMenuInflater().inflate(R.menu.main, menu);
return true;
}
#Override
public boolean onOptionsItemSelected(MenuItem item) {
// Handle action bar item clicks here. The action bar will
// automatically handle clicks on the Home/Up button, so long
// as you specify a parent activity in AndroidManifest.xml.
int id = item.getItemId();
if (id == R.id.action_settings) {
return true;
}
return super.onOptionsItemSelected(item);
}
/**
* A placeholder fragment containing a simple view.
*/
public static class PlaceholderFragment extends Fragment {
public PlaceholderFragment() {
}
#Override
public View onCreateView(LayoutInflater inflater, ViewGroup container,
Bundle savedInstanceState) {
View rootView = inflater.inflate(R.layout.fragment_main, container, false);
return rootView;
}
}
}
UPDATED:
This has the updated code, and runs error free... but the button still will not go to the new activity when I run it.
package ie.gmit.project;
import android.support.v7.app.ActionBarActivity;
import android.support.v7.app.ActionBar;
import android.support.v4.app.Fragment;
import android.content.Intent;
import android.net.Uri;
import android.os.Bundle;
import android.view.LayoutInflater;
import android.view.Menu;
import android.view.MenuItem;
import android.view.View;
import android.view.ViewGroup;
import android.widget.Button;
import android.os.Build;
public class MainActivity extends ActionBarActivity {
private Button button2;//this is a bad name
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
button2= (Button) findViewById(R.id.button2);//find the button
button2.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View v) {
Intent i = new Intent(v.getContext(), IntroActivity.class);
startActivity(i);
// finish();//if you want to close main activity after start info activity
}});
if (savedInstanceState == null) {
getSupportFragmentManager().beginTransaction()
.add(R.id.container, new PlaceholderFragment())
.commit();
}
}
public void openSite(View v){
Uri uri = Uri.parse("http://gmitsu.ie/clubssocs/directory.html");
Intent intent = new Intent(Intent.ACTION_VIEW, uri);
startActivity(intent);
}
#Override
public boolean onCreateOptionsMenu(Menu menu) {
// Inflate the menu; this adds items to the action bar if it is present.
getMenuInflater().inflate(R.menu.main, menu);
return true;
}
#Override
public boolean onOptionsItemSelected(MenuItem item) {
// Handle action bar item clicks here. The action bar will
// automatically handle clicks on the Home/Up button, so long
// as you specify a parent activity in AndroidManifest.xml.
int id = item.getItemId();
if (id == R.id.action_settings) {
return true;
}
return super.onOptionsItemSelected(item);
}
/**
* A placeholder fragment containing a simple view.
*/
public static class PlaceholderFragment extends Fragment {
public PlaceholderFragment() {
}
#Override
public View onCreateView(LayoutInflater inflater, ViewGroup container,
Bundle savedInstanceState) {
View rootView = inflater.inflate(R.layout.fragment_main, container, false);
return rootView;
}
}
}
Manifest
<?xml version="1.0" encoding="utf-8"?>
<manifest xmlns:android="http://schemas.android.com/apk/res/android"
package="ie.gmit.project"
android:versionCode="1"
android:versionName="1.0" >
<uses-sdk
android:minSdkVersion="8"
android:targetSdkVersion="19" />
<application
android:allowBackup="true"
android:icon="#drawable/ic_launcher"
android:label="#string/app_name"
android:theme="#style/AppTheme" >
<activity
android:name="ie.gmit.project.MainActivity"
android:label="#string/app_name" >
<intent-filter>
<action android:name="android.intent.action.MAIN" />
<category android:name="android.intent.category.LAUNCHER" />
</intent-filter>
</activity>
<activity
android:name="ie.gmit.project.IntroActivity"
android:label="#string/title_activity_intro" >
</activity>
</application>
</manifest>

try this
public class MainActivity extends Activity {
private Button button2;//this is a bad name
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.main_activity);
button2= (Button) findViewById(R.id.button2);//find the button
button2.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View v) {
Intent i = new Intent(v.getContext(), InfoActivity.class);
startActivity(i);
finish();//if you want to close main activity after start info activity
});
}
declare in manifest intro activity in manifest
<activity
android:name=".IntroActivity"
android:label="Intro Activity"
android:theme="#android:style/Theme.Light.NoTitleBar.Fullscreen" >
</activity>
if this does not work you can add entries to the log to see if the data are assigning well, such as:
#Override
public void onClick(View v) {
Log.i("MyLog", "Im here!");
Intent i = new Intent(v.getContext(), InfoActivity.class);
startActivity(i);
finish();//if you want to close main activity after start info activity
});