I tried to display User Input from my main activity to my second activity, but when I typed in and click the send button on the main activity the whole app just crashes. Please help!
crash solved! Thanks a lot! However, I can't get the message to display on the second activity.
MainActivity.java
package com.example.dell_inspiron.sendmessage;
import android.content.Intent;
import android.support.v7.app.AppCompatActivity;
import android.os.Bundle;
import android.view.View;
import android.widget.Button;
import android.widget.EditText;
import static android.R.id.message;
public class MainActivity extends AppCompatActivity {
@Override
protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_main);
    final String message = getResources().getString(R.string.UserInput);
    final Button send = (Button) findViewById(R.id.send);
    send.setOnClickListener(new View.OnClickListener()
    {
        public void onClick(View v) {
            Intent sendMessage = new Intent(MainActivity.this,     DisplayMessageActivity.class);
            sendMessage.putExtra("UserInput", message);
            startActivity(sendMessage);
        }
    });
}
}
activity_main.xml
<?xml version="1.0" encoding="utf-8"?>
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:tools="http://schemas.android.com/tools"
android:id="@+id/activity_main"
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.dell_inspiron.sendmessage.MainActivity">
<EditText
    android:layout_width="wrap_content"
    android:layout_height="wrap_content"
    android:inputType="textPersonName"
    android:text="@string/edit"
    android:ems="10"
    android:layout_below="@+id/textView"
    android:layout_alignParentLeft="true"
    android:layout_alignParentStart="true"
    android:layout_marginTop="15dp"
    android:id="@+id/UserInput" />
<Button
    android:text="@string/send"
    android:layout_width="wrap_content"
    android:layout_height="wrap_content"
    android:layout_below="@+id/UserInput"
    android:layout_alignParentLeft="true"
    android:layout_alignParentStart="true"
    android:layout_marginTop="14dp"
    android:id="@+id/send"
    android:onClick="sendMessage" />
<TextView
    android:text="@string/text"
    android:layout_width="wrap_content"
    android:layout_height="wrap_content"
    android:id="@+id/textView"
    android:textSize="18sp"
    android:layout_alignParentTop="true"
    android:layout_alignParentLeft="true"
    android:layout_alignParentStart="true" />
</RelativeLayout>
DisplayMessageActivity.java
package com.example.dell_inspiron.sendmessage;
import android.content.Intent;
import android.support.v7.app.AppCompatActivity;
import android.os.Bundle;
import android.view.View;
import android.view.ViewGroup;
import android.widget.Button;
import android.widget.EditText;
import android.widget.TextView;
public class DisplayMessageActivity extends AppCompatActivity {
@Override
protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_display_message);
    Intent Extra = getIntent();
    String textView = Extra.getStringExtra("UserInput");
    TextView UserInput = (TextView) findViewById(R.id.UserOutput);
    UserInput.setText(textView);
    final Button button = (Button) findViewById(R.id.button2);
    button.setOnClickListener(new View.OnClickListener()
    {
        public void onClick(View v) {
            launchActivity();
        }
    });
}
private void launchActivity() {
    Intent intent = new Intent(this, MainActivity.class);
    startActivity(intent);
}
}
activity_display_message.xml
<?xml version="1.0" encoding="utf-8"?>
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:tools="http://schemas.android.com/tools"
android:id="@+id/activity_display_message"
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.dell_inspiron.sendmessage.DisplayMessageActivity">
<Button
    android:text="@string/Button2"
    android:layout_width="wrap_content"
    android:layout_height="wrap_content"
    android:layout_alignParentBottom="true"
    android:layout_centerHorizontal="true"
    android:layout_marginBottom="51dp"
    android:id="@+id/button2" />
<TextView
    android:text="@string/UserOutput"
    android:layout_width="wrap_content"
    android:layout_height="wrap_content"
    android:layout_alignParentTop="true"
    android:layout_centerHorizontal="true"
    android:layout_marginTop="91dp"
    android:id="@+id/UserOutput" />
<TextView
    android:text="@string/enter"
    android:layout_width="wrap_content"
    android:layout_height="wrap_content"
    android:layout_alignParentTop="true"
    android:layout_alignParentLeft="true"
    android:layout_alignParentStart="true"
    android:id="@+id/enter"
    android:textSize="18sp"
    android:textColor="@android:color/holo_purple" />
</RelativeLayout>
 
     
     
    