Linear Layout

Android 2011. 6. 9. 15:13

Linear Layout

LinearLayout is a ViewGroup that displays child View elements in a linear direction, either vertically or horizontally.

지나친 LinearLayout사용에 주의를 할 필요가 있습니다.중첩된 여러 LinearLayout들을 사용하려면, RelativeLayout 사용을 고려할 수 있습니다.

HelloLinearLayout.라는 이름의 새로운 프로젝트를 생성합니다.

res/layout/main.xml 를 열어 삽입합니다.

<?xml version="1.0" encoding="utf-8"?>

<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"

    android:orientation="vertical"

    android:layout_width="fill_parent"

    android:layout_height="fill_parent">



  <LinearLayout

      android:orientation="horizontal"

      android:layout_width="fill_parent"

      android:layout_height="fill_parent"

      android:layout_weight="1">

      <TextView

          android:text="red"

          android:gravity="center_horizontal"

          android:background="#aa0000"

          android:layout_width="wrap_content"

          android:layout_height="fill_parent"

          android:layout_weight="1"/>

      <TextView

          android:text="green"

          android:gravity="center_horizontal"

          android:background="#00aa00"

          android:layout_width="wrap_content"

          android:layout_height="fill_parent"

          android:layout_weight="1"/>

      <TextView

          android:text="blue"

          android:gravity="center_horizontal"

          android:background="#0000aa"

          android:layout_width="wrap_content"

          android:layout_height="fill_parent"

          android:layout_weight="1"/>

      <TextView

          android:text="yellow"

          android:gravity="center_horizontal"

          android:background="#aaaa00"

          android:layout_width="wrap_content"

          android:layout_height="fill_parent"

          android:layout_weight="1"/>

  </LinearLayout>

        

  <LinearLayout

    android:orientation="vertical"

    android:layout_width="fill_parent"

    android:layout_height="fill_parent"

    android:layout_weight="1">

    <TextView

        android:text="row one"

        android:textSize="15pt"

        android:layout_width="fill_parent"

        android:layout_height="wrap_content"

        android:layout_weight="1"/>

    <TextView

        android:text="row two"

        android:textSize="15pt"

        android:layout_width="fill_parent"

        android:layout_height="wrap_content"

        android:layout_weight="1"/>

    <TextView

        android:text="row three"

        android:textSize="15pt"

        android:layout_width="fill_parent"

        android:layout_height="wrap_content"

        android:layout_weight="1"/>

    <TextView

        android:text="row four"

        android:textSize="15pt"

        android:layout_width="fill_parent"

        android:layout_height="wrap_content"

        android:layout_weight="1"/>

  </LinearLayout>



</LinearLayout>

신중하게 XML을 확인하십시요. LinearLayout 는 최상위 입니다.that defines its orientation to be vertical—all child Views (of which it has two) will be stacked vertically. The first child is another LinearLayout that uses a horizontal orientation and the second child is a LinearLayout that uses a vertical orientation. Each of these nested LinearLayouts contain several TextView elements, which are oriented with each other in the manner defined by their parent LinearLayout.

Now open HelloLinearLayout.java and be sure it loads the res/layout/main.xml layout in the onCreate() method:
```
public void onCreate(Bundle savedInstanceState) {

    super.onCreate(savedInstanceState);

    setContentView(R.layout.main);

}
```
The setContentView(int) method loads the layout file for the Activity, specified by the resource ID — R.layout.main refers to the res/layout/main.xml layout file.
Run the application.

You should see the following:

Notice how the XML attributes define each View's behavior. Try experimenting with different values for android:layout_weight to see how the screen real estate is distributed based on the weight of each element. See the Common Layout Objects document for more about how LinearLayout handles the android:layout_weight attribute.