Hello World

MainActivity.java

package com.incheon.our.ch03a;
import android.os.Bundle;
import android.support.v7.app.AppCompatActivity;
import android.widget.TextView;
public class MainActivity extends AppCompatActivity {
    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
        TextView tv = (TextView)findViewById(R.id.textView);
        tv.setText("Java Code Text View\n Hello World!");
    }
}



string.xml

<resources>
    <string name="app_name">ch03a</string>
    <string name="hello">Hello, World!</string>
</resources>



activity_main.xml
<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:orientation="vertical">
    <TextView
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:text="@string/hello"
        app:layout_constraintBottom_toBottomOf="parent"
        app:layout_constraintLeft_toLeftOf="parent"
        app:layout_constraintRight_toRightOf="parent"
        app:layout_constraintTop_toTopOf="parent" />
    <TextView
        android:id="@+id/textView"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_weight="1"
        android:text="TextView" />
</LinearLayout>





개발환경 : Android Studio 2.3.3
언어 : JAVA
ch03a.z01
ch03a.z02
ch03a.zip