My project is fairly simple for training purposes only. I am trying to load another interface/view/activity when I click a button on my main layout. Here is the code for the main activity:
package com.example.interfacemanipulation;
import android.app.Activity;
import android.content.Intent;
import android.os.Bundle;
import android.view.Menu;
import android.view.View;
import android.widget.EditText;
public class MainActivity extends Activity {
public static final String EXTRA_MESSAGE = "Something Here....";
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
}
#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;
}
public void goToWelcomeActivityMethod(View view)
{
Intent intent = new Intent(this, WelcomeActivity.class);
EditText editText = (EditText) findViewById(R.id.welcomeMessage);
String message = editText.getText().toString();
intent.putExtra(EXTRA_MESSAGE, message);
startActivity(intent);
}
}
And this is the code in the other activity:
package com.example.interfacemanipulation;
import android.app.Activity;
import android.content.Intent;
import android.os.Bundle;
import android.view.Menu;
import android.widget.TextView;
public class WelcomeActivity extends Activity {
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
Intent intent = getIntent();
String message = intent.getStringExtra(MainActivity.EXTRA_MESSAGE);
TextView textView = new TextView(this);
textView.setTextSize(40);
textView.setText(message);
// Set the text view as the activity layout
setContentView(textView);
}
#Override
public boolean onCreateOptionsMenu(Menu menu) {
// Inflate the menu; this adds items to the action bar if it is present.
getMenuInflater().inflate(R.menu.welcome, menu);
return true;
}
}
the code here is basically modified from Google documentation. I just want to be able to load the view of the second activity with label in it. Here is my manifest:
<?xml version="1.0" encoding="utf-8"?>
<manifest xmlns:android="http://schemas.android.com/apk/res/android"
package="com.example.interfacemanipulation"
android:versionCode="1"
android:versionName="1.0" >
<uses-sdk
android:minSdkVersion="8"
android:targetSdkVersion="17" />
<application
android:allowBackup="true"
android:icon="#drawable/ic_launcher"
android:label="#string/app_name"
android:theme="#style/AppTheme" >
<activity
android:name="com.example.interfacemanipulation.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="com.example.interfacemanipulation.WelcomeActivity"
android:label="#string/title_activity_welcome" >
</activity>
</application>
</manifest>
I've only been trying android for the last 4 days...so I appreciate your support
You have 2 problems: 1. You don't have the button to take you to the activity (or at least you haven't shown it in the code you posted. If you do, then you don't have the onClickListener set for that button). 2. You don't call the method that takes you to your second activity.
To have a button that takes you to another activity, you need to add the button to the layout, and then add the onClickListener, which executes your goToWelcomeActivityMethod when you click on it, like so:
import android.app.Activity;
import android.content.Intent;
import android.os.Bundle;
import android.view.Menu;
import android.view.View;
import android.widget.EditText;
public class MainActivity extends Activity {
public static final String EXTRA_MESSAGE = "Something Here....";
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
//this will insert the button into the Main Activity layout
Button goToWelcome = (Button)findViewById(R.id.goToWelcome);
//this is the onClickListener which will call the method to go to the next activity
goToWelcome.setOnClickListener(new View.OnClickListener()
{
public void onClick(View v)
{
goToWelcomeActivityMethod();
}
});
}
#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;
}
//you don't need to pass in the View
public void goToWelcomeActivityMethod()
{
Intent intent = new Intent(this, WelcomeActivity.class);
EditText editText = (EditText) findViewById(R.id.welcomeMessage);
String message = editText.getText().toString();
intent.putExtra(EXTRA_MESSAGE, message);
startActivity(intent);
}
}
Then in your XML file make sure you add the button too:
<Button
android:id="#+id/goToWelcome"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_alignParentBottom="true"
android:text="Go To Welcome" />
in the main activity's layout XML, add the attribute android:onClick="goToWelcomeActivityMethod" to the button declaration.
In this way, the method goToWelcomeActivityMethod is called when you press the button.
For the "other" way, check https://developer.android.com/reference/android/widget/Button.html
Related
I'm new to android developing but have experience with python and java, so I decided I want to make apps, thus i began the tutorial from developer.android.com.
I'm in the Build your first app > Starting Another Activity section.
I made it to the final step without errors, BUT the message I type in is not showing up in the second activity created when i press the send button!
(https://developer.android.com/training/basics/firstapp/starting-activity.html#DisplayMessage) if you click that link to see the tutorial, and you scroll down to the bottom, you should see that the message you type should pop up, and with a bigger font size.
The message i find when i type ANYTHING is the small font, default "Hello world!"
Here's my MyActivity.java
package com.example.android.myfirstapp;
import android.app.Fragment;
import android.support.v7.app.AppCompatActivity;
import android.os.Bundle;
import android.view.Menu;
import android.view.MenuItem;
import android.content.Intent;
import android.view.View;
import android.widget.EditText;
public class MyActivity extends AppCompatActivity {
public final static String EXTRA_MESSAGE = "com.mycompany.myfirstapp.MESSAGE";
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_my);
}
#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_my, 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);
}
/* Called when the user clicks the Send button */
public void SendMessage(View view) //View must be the parameter of onClick, View is what is pressed.
{
// Do something in response
Intent intent = new Intent(this, DisplayMessageActivity.class); //A Context as its first parameter (this is used because the Activity class is a subclass of Context)
EditText editText = (EditText) findViewById(R.id.edit_message);
String message = editText.getText().toString();
intent.putExtra(EXTRA_MESSAGE, message);
startActivity(intent);
}
}
Here is the DisplayMessageActivity.java
package com.example.android.myfirstapp;
import android.content.Intent;
import android.support.v7.app.AppCompatActivity;
import android.os.Bundle;
import android.view.Menu;
import android.view.MenuItem;
import android.widget.TextView;
public class DisplayMessageActivity extends AppCompatActivity {
#Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
// Get the message from the intent
Intent intent = getIntent();
String message = intent.getStringExtra(MyActivity.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);
}
#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);
}
}
I'm not sure if you guys would need AndroidManifest.xml, activity_my.xml, or strings.xml but it's better to be safe than sorry!
AndroidManifest.xml below:
<?xml version="1.0" encoding="utf-8"?>
<manifest xmlns:android="http://schemas.android.com/apk/res/android"
package="com.example.android.myfirstapp" >
<application
android:allowBackup="true"
android:icon="#mipmap/ic_launcher"
android:label="#string/app_name"
android:theme="#style/AppTheme" >
<activity
android:name=".MyActivity"
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=".DisplayMessageActivity"
android:label="#string/title_activity_display_message" >
</activity>
</application>
</manifest>
activity_my.xml below:
<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"
/>
strings.xml below:
<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</string>
</resources>
I apologize some of the things are not indented properly if they didn't indent properly when I copy pasted them over here.
If you could help me, I would really appreciate it, so i can continue becoming an android developer!
Again, the app is a simple type a message and send, to see your message pop up with bigger font size in another activity. Though mine is only showing the default, small-font-sized "Hello world!" when the new activity pops up when i press send.
Thank you for your time, and sorry for the long post!
First of all, replace
intent.putExtra(EXTRA_MESSAGE, message);
with
intent.putExtra("EXTRA_MESSAGE", message);
in your MyActivity.java
as the first argument for putExtra() should be a String name, which is used further in the application. Please refer the [docs](http://developer.android.com/reference/android/content/Intent.html#putExtra(java.lang.String, android.os.Bundle))
Now, in your DisplayMessageActivity.java
write your onCreate() as follows
#Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
// Set your parent view
setContentView(R.layout.disp_msg_layout);
// Get the message from the intent
Intent intent = getIntent();
String message = intent.getStringExtra("EXTRA_MESSAGE");
// Get the reference to the TextView and update it's content
TextView textView = (TextView)findViewById(R.id.my_text_view);
textView.setText(message);
}
and declare an xml file named disp_msg_layout in your layouts and it should be like
<?xml version="1.0" encoding="utf-8"?>
<TextView xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:textSize="40sp"
android:id="#+id/my_text_view"/>
Followed a tutorial but doesnt seem to work on emulation.
MainActivity.java:
package b.myfirstapp;
import android.app.Activity;
import android.support.v7.app.ActionBarActivity;
import android.os.Bundle;
import android.view.Menu;
import android.view.MenuItem;
import android.content.Context;
import android.content.Intent;
import android.widget.Button;
import android.view.View;
import android.view.View.OnClickListener;
public class MainActivity extends Activity {
Button button;
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
}
#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);
}
public void addListenerOnButton() {
final Context context = this;
button = (Button) findViewById(R.id.button);
button.setOnClickListener(new OnClickListener() {
#Override
public void onClick(View arg0) {
Intent intent = new Intent(context, Activity2.class);
startActivity(intent);
}
});
}
}
Activity2.java:
package b.myfirstapp;
import android.app.Activity;
import android.os.Bundle;
import android.widget.Button;
public class Activity2 extends Activity {
Button button;
#Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main2);
}
}
Manifest:
<?xml version="1.0" encoding="utf-8"?>
<manifest xmlns:android="http://schemas.android.com/apk/res/android"
package="b.myfirstapp" >
<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:label="#string/app_name"
android:name=".Activity2" >
</activity>
</application>
</manifest>
There are no errors in the code, its just that when i emulate it it doesnt work, maybe ive coded it incorrectly, not too sure, it looks fine to me.
I'm new to android dev so im confused. Help!
UPDATED: (For clearance purposes with comments properly inserted)
I think you are missing the call to addListenerOnButton in your MainActivity class, for example inside onCreate right after setContentView....
Also, you should make it private since it's only going to be called from within this class.
You have not called your addListenerOnButton method so you have not set onClick handler to your button.
Your onCreate should look like this:
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
addListenerOnButton()
}
I have two applications with one activity in each of them. Application A and application B. Application A has its activity's launch type as SingleTask. Both Activities have buttons calling each other. What I want is that when I launch activity A from activity B's button which is in turn launched from activity A's button, and then when I press back button activity B should come to foreground. But instead it is going back to launcher. I have attached code for reference.
Application A MainActivity:-
package com.example.appa;
import android.support.v7.app.ActionBarActivity;
import android.content.Intent;
import android.os.Bundle;
import android.view.Menu;
import android.view.MenuItem;
import android.view.View;
import android.widget.Button;
public class MainActivity extends ActionBarActivity {
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
Button b1= (Button)findViewById(R.id.button1);
b1.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View v) {
// TODO Auto-generated method stub
Intent i =new Intent();
i.setClassName("com.example.appb", "com.example.appb.MainActivity");
startActivity(i);
}
});
}
#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);
}
}
Application A Manifest:-
<?xml version="1.0" encoding="utf-8"?>
<manifest xmlns:android="http://schemas.android.com/apk/res/android"
package="com.example.appa"
android:versionCode="1"
android:versionName="1.0" >
<uses-sdk
android:minSdkVersion="8"
android:targetSdkVersion="21" />
<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"
android:launchMode="singleTask"
>
<intent-filter>
<action android:name="android.intent.action.MAIN" />
<category android:name="android.intent.category.LAUNCHER" />
</intent-filter>
</activity>
</application>
</manifest>
Application B MainActivity:
package com.example.appb;
import com.example.appb.R;
import android.support.v7.app.ActionBarActivity;
import android.content.Intent;
import android.os.Bundle;
import android.view.Menu;
import android.view.MenuItem;
import android.view.View;
import android.widget.Button;
public class MainActivity extends ActionBarActivity {
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
Button b1= (Button)findViewById(R.id.button1);
b1.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View v) {
// TODO Auto-generated method stub
Intent i =new Intent();
i.setClassName("com.example.appa", "com.example.appa.MainActivity");
i.setFlags(Intent.FLAG_ACTIVITY_REORDER_TO_FRONT);
startActivity(i);
}
});
}
Application B Manifest is unmodified default mainfest
As it can be seen I have already tried FLAG_ACTIVITY_REORDER_TO_FRONT but it did not help.
P.S :- I cannot change launch type of activity in application A
Thanks in advance
The singleTask launch mode is not compatible with that behavior. You can set a different launch mode each time you start an activity by setting flags, but a better approach might be to reevaluate the choice made for default launch mode.
Tasks and back stack article.
I'm following the tutorial from the following link: https://developer.android.com/training/basics/firstapp/starting-activity.html
The problem I'm facing is, I able to trigger the sendMessage method however it just failed to show the expected result?
Please take a look at the following code:
activity_main.xml (Parent layout):
<EditText android:id="#+id/edit_message"
android:layout_width="0dp"
android:layout_height="wrap_content"
android:layout_weight="1"
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>
MainActivity.java:
package com.example.myfirstapp;
import android.content.Intent;
import android.os.Bundle;
import android.support.v7.app.ActionBarActivity;
import android.view.Menu;
import android.view.MenuItem;
import android.view.View;
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);
}
#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);
}
/** Called when the user clicks the Send button */
public void sendMessage(View view) {
// Do something in response to button
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);
}
}
activity_display_message.xml (Children layout):
<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.myfirstapp.DisplayMessageActivity" >
<TextView
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:text="#string/hello_world" />
</RelativeLayout>
DisplayMessageActivity.java:
package com.example.myfirstapp;
import android.app.Fragment;
import android.content.Intent;
import android.os.Bundle;
import android.support.v7.app.ActionBarActivity;
import android.view.LayoutInflater;
import android.view.MenuItem;
import android.view.View;
import android.view.ViewGroup;
import android.widget.TextView;
public class DisplayMessageActivity extends ActionBarActivity {
#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);
}
#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.activity_display_message,
container, false);
return rootView;
}
}
}
MyFirstApp Manifest:
<?xml version="1.0" encoding="utf-8"?>
<manifest xmlns:android="http://schemas.android.com/apk/res/android"
package="com.example.myfirstapp"
android:versionCode="1"
android:versionName="1.0" >
<uses-sdk
android:minSdkVersion="16"
android:targetSdkVersion="16" />
<uses-permission android:name="android.permission.WRITE_EXTERNAL_STORAGE" />
<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=".DisplayMessageActivity"
android:label="#string/title_activity_display_message"
android:parentActivityName=".MainActivity" >
<meta-data
android:name="android.support.PARENT_ACTIVITY"
android:value="com.example.myfirstapp.MainActivity" />
</activity>
</application>
</manifest>
P/S: I've set a breakpoint at DisplayMessageActivity.java onCreate() method but it wasn't being triggered.
You are missing a startActivity statement. Your MainActivity.sendMessage it should be like the follwing:
/** Called when the user clicks the Send button */
public void sendMessage(View view) {
// Do something in response to button
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); /// <---- THIS LINE
}
Hope it helps
Add below line
startActivity(intent);
under
intent.putExtra(EXTRA_MESSAGE, message);
And Call sendMessage() on button click
Add
startActivity(intent)
after this line
intent.putExtra(EXTRA_MESSAGE, message);
This why there's no response upon clicking the button.
1) You are not attaching Listener to your button. Do it like :
Button myButton = (Button) findViewById(R.id.my_button);
myButton.setOnItemClickListener(new OnItemClickListener() {
#Override
public void onItemClick(AdapterView<?> parent, View v,
int position, long id) {
sendMessage(); //this is the action to be taken.
}
});
2) You are creating the Intent object, but not firing it. Use startActivity(intent) as the last line of sendMessage() method to fire the intent and get the desired results.
Shifting between activities isn't working.
What the app does is it opens the android.xml file then after 5 secs open the main file
Here's the code:
android manifest file:
<?xml version="1.0" encoding="utf-8"?>
<manifest xmlns:android="http://schemas.android.com/apk/res/android"
package="com.example.android"
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="com.example.android.MainActivity"
android:label="#string/app_name" >
<intent-filter>
<action android:name="android.intent.action.MAIN" />
<category android:name="android.intent.category.DEFAULT" />
</intent-filter>
</activity>
<activity
android:name="com.example.android.android"
android:label="#string/app_name" >
<intent-filter>
<action android:name="android.intent.action.ANDROID" />
<category android:name="android.intent.category.LAUNCHER" />
</intent-filter>
</activity>
</application>
android.java file:
package com.example.android;
import android.app.Activity;
import android.content.Intent;
import android.media.MediaPlayer;
import android.os.Bundle;
public class android extends Activity{
MediaPlayer sound1;
#Override
protected void onCreate(Bundle savedInstanceState) {
// TODO Auto-generated method stub
super.onCreate(savedInstanceState);
setContentView(R.layout.android);
sound1 = MediaPlayer.create(android.this , R.raw.android);
sound1.start();
Thread timer = new Thread()
{public void run()
{
try{
sleep(5000);
}
catch(InterruptedException ac){
ac.printStackTrace();
}
finally{
Intent openactivity = new Intent ("android.intent.action.MAIN");
startActivity(openactivity);
}
}
};
timer.start();
}
#Override
protected void onPause() {
// TODO Auto-generated method stub
super.onPause();
sound1.release();
finish();
}
}
Mainactivity.java:
package com.example.android;
import android.support.v7.app.ActionBarActivity;
import android.support.v7.app.ActionBar;
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;
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();
}
}
#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;
}
}
}
android.xml file:(the first file that launches up)
<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:orientation="vertical"
android:background = "#drawable/android"
>
</LinearLayout>
Try this way
Intent openactivity = new Intent(android.this,MainActivity.class);
startActivity(openactivity);
And for more information go to starting-new-activity
First, always Capitalise 1st letter of class names (code convention),
and then write your intents like below:
Intent intent = new Intent(android.this, MainActivity.class);
startActivity(intent );
You can check Starting Another Activity in Android Developers website.