Android入门系列：UI组件：布局管理器：GridLayout

<?xml version="1.0" encoding="utf-8"?>
<GridLayout xmlns:android="http://schemas.android.com/apk/res/android"

    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:layout_gravity="center"
    android:useDefaultMargins="true"
    android:columnCount="4"
    >
    
    <Button 
        android:text="@string/zero"
        android:background="#DFDFDF"
        android:textSize="30sp"
        android:layout_columnSpan="4"
        android:gravity="center_vertical|right"
        android:paddingRight="8dp"
        android:layout_gravity="fill"
        android:clickable="false"
        />
    
    <Button 
        android:text="@string/clear"
        android:layout_columnSpan="3"
        android:layout_gravity="fill"
        />
    <Button
        android:text="@string/divide"
        android:layout_gravity="fill"
        />
    <Button 
        android:text="@string/one"
        android:layout_gravity="fill"
        />
    <Button 
        android:text="@string/two"
        android:layout_gravity="fill"
        />
    <Button 
        android:text="@string/three"
        android:layout_gravity="fill"
        />
    <Button 
        android:text="@string/multiply"
        android:layout_gravity="fill"
        />
    <Button 
        android:text="@string/four"
        android:layout_gravity="fill"
        />
    <Button 
        android:text="@string/five"
        android:layout_gravity="fill"
        />
    <Button 
        android:text="@string/six"
        android:layout_gravity="fill"
        />
    <Button 
        android:text="@string/sub"
        android:layout_gravity="fill"
        />
    <Button 
        android:text="@string/seven"
        android:layout_gravity="fill"
        />
    <Button 
        android:text="@string/eight"
        android:layout_gravity="fill"
        />
    <Button 
        android:text="@string/nine"
        android:layout_gravity="fill"
        />
    <Button 
        android:text="@string/add"
        android:layout_rowSpan="3"
        android:layout_gravity="fill"
        />
    <Button 
        android:text="@string/zero"
        android:layout_columnSpan="2"
        android:layout_gravity="fill"
        />
    <Button 
        android:text="@string/dot"
        android:layout_gravity="fill"
        />                   
    <Button 
        android:text="@string/equal"
        android:layout_columnSpan="3"
        android:layout_gravity="fill"
        />        

</GridLayout>

<?xml version="1.0" encoding="utf-8"?>
<resources>
    <string name="app_name">My Second App</string>
    <string name="hello_world">Hello world!</string>
    <string name="action_settings">Settings</string>
    <string name="str_hello">Hello，安卓!</string>
    <string name="calc_title">计算器</string>
    <string name="zero">0</string>
    <string name="one">1</string>
    <string name="two">2</string>
    <string name="three">3</string>
    <string name="four">4</string>
    <string name="five">5</string>
    <string name="six">6</string>
    <string name="seven">7</string>
    <string name="eight">8</string>
    <string name="nine">9</string>
    <string name="dot">.</string>
    <string name="add">+</string>
    <string name="sub">-</string>
    <string name="multiply">*</string>
    <string name="divide">/</string>
    <string name="equal">=</string>
    <string name="clear">C</string>
</resources>