How can I display text above a button?

Only the button displays, but I want to see the text above the button

<RelativeLayout
  android:id="@+id/big_button_layout"
  android:layout_width="match_parent"
  android:layout_height="match_parent"
  android:visibility="gone">
  <ImageButton
   android:id="@+id/big_button"
   android:layout_width="match_parent"开发者_StackOverflow中文版
   android:layout_height="match_parent"
   android:src="@drawable/girrafffe"/>
  <TextView
   android:layout_width="match_parent"
   android:layout_height="match_parent"
   android:gravity="center_horizontal"
   android:text="Hello"
   android:layout_above="@id/big_button"/>
 </RelativeLayout>

<Button
  android:id="@+id/button_send"
  android:layout_width="150px"
  android:layout_height="wrap_content"
  android:padding="20dp"
  android:drawableBottom="@drawable/image"
  android:background="@android:color/transparent"
  android:text="@string/send"
  android:gravity="center"
  android:layout_gravity="center"
/>

android:drawableBottom="@drawable/image" will place the image of the button on the bottom thus allowing the text to be placed on the top.

Use a TextView.

<RelativeLayout
  android:id="@+id/big_button_layout"
  android:layout_width="match_parent"
  android:layout_height="match_parent"
  android:visibility="gone">
  <TextView
   android:layout_width="match_parent"
   android:layout_height="match_parent"
   android:gravity="center_horizontal"
   android:text="Big Button"/>
  <ImageButton
   android:id="@+id/big_button"
   android:layout_width="match_parent"
   android:layout_height="match_parent"
   android:src="@drawable/girrafffe"/>
  <TextView
   android:layout_width="match_parent"
   android:layout_height="match_parent"
   android:gravity="center_horizontal"
   android:layout_above="@id/big_button"/>
 </RelativeLayout>  

You may need to add some layouts to line everything up. However, this may work without them.