1. match_parent
When you set layout width and height as match_parent, it will occupy the complete area that the parent view has, i.e. it will be as big as the parent.
Note : If parent is applied a padding then that space would not be included.
When we create a layout.xml by default we have RelativeLayout as default parent View with android:layout_width="match_parent" and android:layout_height="match_parent" i.e it occupies the complete width and height of the mobile screen.
Also note that padding is applied to all sides,
android:paddingBottom="@dimen/activity_vertical_margin"
android:paddingLeft="@dimen/activity_horizontal_margin"
android:paddingRight="@dimen/activity_horizontal_margin"
android:paddingTop="@dimen/activity_vertical_margin"
Now lets add a sub-view LinearLayout and sets its layout_width="match_parent" and layout_height="match_parent", the graphical view would display something like this,
match_parent_example
Code
xmlns:tools="http://schemas.android.com/tools"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:paddingBottom="@dimen/activity_vertical_margin"
android:paddingLeft="@dimen/activity_horizontal_margin"
android:paddingRight="@dimen/activity_horizontal_margin"
android:paddingTop="@dimen/activity_vertical_margin"
tools:context="com.code2care.android.togglebuttonexample.MainActivity" >
android:layout_width="match_parent"
android:layout_height="match_parent"
android:layout_alignParentLeft="true"
android:layout_alignParentTop="true"
android:layout_marginLeft="11dp"
android:background="#FFFFEE"
android:orientation="vertical" >
2. fill_parent :
This is same as match_parent, fill_parent was depreciated in API level 8. So if you are using API level 8 or above you must avoid using fill_parent
Lets follow the same steps as we did for match_parent, just instead use fill_parent everywhere.
You would see that there is no difference in behaviour in both fill_parent and match parent.