title: Add seek bar on map using Map API V2 in android
body: <p>I am working on a application in which i am using Google Map Api V2, the map is successfully loaded, also i have put markers on it but now when i tried to add a seek bar on my map its not showing it on map's surface, actually i want to give a feature in which a user can increase and decrease the radius of circle using seek bar, but when i add that seek bar through XML its not showing me the seek bar, </p>
  
  <p>my XML is like that :-</p>
  
  <pre><code>&lt;RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
      xmlns:tools="http://schemas.android.com/tools"
      android:layout_width="match_parent"
      android:layout_height="match_parent"
      tools:context=".MainActivity" &gt;
  
      &lt;RadioGroup
          android:id="@+id/rg_views"
          android:layout_width="wrap_content"
          android:layout_height="wrap_content"
          android:orientation="horizontal" &gt;
  
          &lt;RadioButton
              android:id="@+id/rb_normal"
              android:layout_width="wrap_content"
              android:layout_height="wrap_content"
              android:checked="true"
              android:text="StreetView" /&gt;
  
          &lt;RadioButton
              android:id="@+id/rb_satellite"
              android:layout_width="wrap_content"
              android:layout_height="wrap_content"
              android:text="Satellite" /&gt;
  
          &lt;RadioButton
              android:id="@+id/rb_terrain"
              android:layout_width="wrap_content"
              android:layout_height="wrap_content"
              android:text="Terrian" /&gt;
      &lt;/RadioGroup&gt;
  
      &lt;RelativeLayout
          android:layout_width="wrap_content"
          android:layout_height="wrap_content"
          android:layout_below="@+id/rg_views" &gt;
  
          &lt;fragment
              xmlns:android="http://schemas.android.com/apk/res/android"
              android:id="@+id/map"
              android:layout_width="match_parent"
              android:layout_height="match_parent"
              class="com.google.android.gms.maps.SupportMapFragment" /&gt;
  
          &lt;SeekBar
              android:id="@+id/bar"
              android:layout_width="wrap_content"
              android:layout_height="wrap_content"
              android:layout_alignParentRight="true"
              android:layout_centerHorizontal="true"
              android:layout_centerVertical="true"
              android:layout_marginRight="-30dp"
              android:max="400"
              android:minWidth="100dp"
              android:progress="100"
              android:rotation="270" /&gt;
      &lt;/RelativeLayout&gt;
  
  &lt;/RelativeLayout&gt;
  </code></pre>
  
  <p>if anyone knows how to place button, seek bar on map's surface then please help me </p>
  
  <p>thanks </p>