want to send text from one activity to another in android

Question

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)

1. 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>

3. 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>

Answer 1

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);

}

Answer 2

Have you added your DisplayMessageActivity in the AndroidManifest.xml in the application tag like:

<activity android:label="@string/app_name" android:name=".DisplayMessageActivity"/>

Answer 3

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();
}