==========================
main.xml
看mars老師的視頻學習安卓裏面的佈局部分，做的樣例，顯擺一下，全部都是在main.xml裏面配置的。
==========================
<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="fill_parent"
android:layout_height="fill_parent"
android:orientation="vertical" >
<LinearLayout
android:layout_width="fill_parent"
android:layout_height="fill_parent"
android:layout_weight="1"
android:orientation="horizontal" >
<TextView
android:layout_width="wrap_content"
android:layout_height="fill_parent"
android:layout_weight="1"
android:background="#0000aa"
android:gravity="center_vertical"
android:text="@string/hello"
android:textSize="30dp" />
<TextView
android:layout_width="wrap_content"
android:layout_height="fill_parent"
android:layout_weight="1"
android:background="#00aa00"
android:gravity="center_vertical"
android:text="@string/hello"
android:textSize="30dp" />
<TextView
android:layout_width="wrap_content"
android:layout_height="fill_parent"
android:layout_weight="1"
android:background="#0000aa"
android:gravity="center_vertical"
android:text="@string/hello"
android:textSize="30dp" />
<TextView
android:layout_width="wrap_content"
android:layout_height="fill_parent"
android:layout_weight="1"
android:background="#00aa00"
android:gravity="center_vertical"
android:text="@string/hello"
android:textSize="30dp" />
</LinearLayout>
<LinearLayout
android:layout_width="fill_parent"
android:layout_height="fill_parent"
android:layout_weight="1"
android:orientation="vertical" >
<TextView
android:layout_width="fill_parent"
android:layout_height="wrap_content"
android:layout_weight="1"
android:background="#00aa00"
android:gravity="center_horizontal"
android:text="@string/hello"
android:textSize="30dp" />
<TextView
android:layout_width="fill_parent"
android:layout_height="wrap_content"
android:layout_weight="1"
android:background="#0000aa"
android:gravity="center_horizontal"
android:text="@string/hello"
android:textSize="30dp" />
<TextView
android:layout_width="fill_parent"
android:layout_height="wrap_content"
android:layout_weight="1"
android:background="#00aa00"
android:gravity="center_horizontal"
android:text="@string/hello"
android:textSize="30dp" />
<TextView
android:layout_width="fill_parent"
android:layout_height="wrap_content"
android:layout_weight="1"
android:background="#0000aa"
android:gravity="center_horizontal"
android:text="@string/hello"
android:textSize="30dp" />
</LinearLayout>
</LinearLayout>
