Question

Sorry to make another topic on this subjcet but I’ve already read several of them and still don’t know why I’m getting this error. I followed the “Building Your First App” tutorial on http://developer.android.com/training/basics/firstapp/index.html and then tried to modify my application to give a layout to DisplayMessageActivity Class. I’ve created a file called “activity_displaymessage.xml” and implemented it to the class.

I’m new to android and I’m trying to understand how this all works. What am I doing wrong?

Here is my code:

MainActivity.java

public class MainActivity extends Activity {

    public final static String EXTRA_MESSAGE = "com.example.sampleandroid.MESSAGE";

        .
        .
        .


    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);
    }
}

DisplayMessageActivity.java

public class DisplayMessageActivity extends Activity {

    @Override
    public void onCreate(Bundle savedInstanceState){
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_displaymessage);

        Intent intent = getIntent();
        String message = intent.getStringExtra(MainActivity.EXTRA_MESSAGE);

        TextView textview = (TextView) findViewById(R.id.text_view);
        textview.setText(message);

        setContentView(textview);
    }
}

activity_displaymessage.xml:

<?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"
    android:weightSum="2">

    <TextView android:id="@+id/text_view"
        android:layout_width="0dp"
        android:layout_height="wrap_content"
        android:layout_weight="1"
        android:textSize="30sp"/>

</LinearLayout>

Answer 1

You have two setContentView.Your layout file activity_displaymessage have already child view R.id.text_view then why are you set it as setContentView().

setContentView(R.layout.activity_displaymessage); and setContentView(textview);

Remove this line setContentView(textview);