How to dock the relative layout to the botton of the screen

I want to dock the button always to the bottom of screen. I am have changed the android:gravity="bottom" to bottom.

I am confused with android:gravity and layout gravity.Well , my question is how can i dock the buttons to the bottom ?

    <Spinner android:id="@+id/alphabets" android:layout_height="wrap_content"
        android:layout_width="match_parent">
    </Spinner>
    <TextView android:layout_width="wrap_content" android:text="TextView"
        android:layout_height="wrap_content" android:id="@+id/textView1"
        android:editable="false" android:textSize="5开发者_开发知识库0sp" android:gravity="center_horizontal"
        android:layout_gravity="center_horizontal">
    </TextView>

    <RelativeLayout android:id="@+id/relativeLayout1"
        android:layout_height="wrap_content" android:gravity="bottom"
        android:layout_width="fill_parent" android:layout_gravity="fill">
        <ImageButton android:layout_width="wrap_content"
            android:id="@+id/imageButton1" 
            android:src="@drawable/arrow_button_left"
            android:layout_height="wrap_content" />
        <ImageButton android:layout_width="wrap_content"
            android:id="@+id/imageButton2" 
            android:src="@drawable/arrow_button_right"
            android:layout_height="wrap_content"
            android:layout_alignParentRight="true" />
    </RelativeLayout>
</LinearLayout>

---

<RelativeLayout 
        android:layout_height="wrap_content" 
        android:layout_width="fill_parent" >

<RelativeLayout android:id="@+id/relativeLayout1"
        android:layout_height="wrap_content" 
        android:layout_width="fill_parent" android:layout_alignParentBottom="true">

<ImageButton android:layout_width="wrap_content"
            android:id="@+id/imageButton1" 
            android:src="@drawable/arrow_button_left"
            android:layout_height="wrap_content" />
        <ImageButton android:layout_width="wrap_content"
            android:id="@+id/imageButton2" 
            android:src="@drawable/arrow_button_right"
            android:layout_height="wrap_content"
            android:layout_alignParentRight="true" />

</RelativeLayout>
</RelativeLayout>

instead taking Linear layout take Relative Layout as parent

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Vertical gravity doesn't work in vertical linear layout. You should fill space between relative layout and text view somehow. For example set android:layout_height="fill_parent" for text view or put some dummy view with layout_height="fill_parent" between them.

---

try this one..

<RelativeLayout android:id="@+id/relativeLayout1"
    android:layout_height="wrap_content" 
    android:layout_width="fill_parent" android:layout_alignParentBottom="true">
<ImageButton android:layout_width="wrap_content"
        android:id="@+id/imageButton1" 
        android:src="@drawable/arrow_button_left"
        android:layout_alignParentBottom="true"
        android:layout_alignParentLeft="true"
        android:layout_height="wrap_content" />
    <ImageButton android:layout_width="wrap_content"
        android:id="@+id/imageButton2" 
        android:src="@drawable/arrow_button_right"
        android:layout_alignParentBottom="true"
        android:layout_alignParentRight="true"
        android:layout_height="wrap_content"
        android:layout_alignParentRight="true" />
       </RelativeLayout> 

---

Try this also if you are planning to have listview with some selectors in footer docking at bottom. Take care of android:layout_above and android:layout_alignParentTop for relativeLayout1 .

<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:id="@+id/RelativeLayout1"
    android:layout_width="fill_parent"
    android:layout_height="fill_parent"
    android:orientation="vertical" >

    <RelativeLayout android:id="@+id/relativeLayout1"
            android:layout_height="wrap_content" 
            android:layout_width="fill_parent" 
            android:layout_alignParentTop="true"
            android:layout_above="@+id/footerRow" >

        <ListView
            android:id="@+id/summaryListView"
            android:layout_width="wrap_content"
            android:layout_height="fill_parent"

            android:layout_alignParentLeft="true"
            android:layout_alignParentTop="true"
            android:choiceMode="singleChoice"
            android:drawSelectorOnTop="true" >

        </ListView>

    </RelativeLayout>

    <TableRow
        android:id="@+id/footerRow"
        android:layout_width="fill_parent"
        android:layout_height="wrap_content"
        android:layout_alignParentLeft="true"
        android:baselineAligned="true"
        android:layout_alignParentBottom="true" >

        <Spinner
            android:id="@+id/_ddlPeriod"
            android:layout_width="fill_parent"
            android:layout_height="wrap_content"
            android:layout_gravity="bottom"
            android:entries="@array/Period_Selector"
             />
    </TableRow>

</RelativeLayout>