layout gets chopped off in a lower resolution screen

In my android app, I have a RelativeLayout with listview and 4 buttons in the bottom. Selecting any item in a listview will make four hidden buttons visible. I have followed the best practices from the http://developer.android.com/guide/practices/screens_support.html. It works fine in the emulator for WVGA800 and in the actual device. I was in a process of testing my app on different screen size. Looks like for QVGA(240x320), the buttons in the bottom gets chopped off. Here is the xml

<?xml version="1.0" encoding="utf-8"?>
 <RelativeLayout android:id="@+id/listViewrelativeLayout" xmlns:android="http://schemas.android.com/apk/res/android" android:layout_width="fill_parent" android:layout_height="fill_parent"  >
  <TextView android:layout_height="wrap_content" android:layout_width="wrap_content" android:id="@+id/info_tv_id" android:textSize="10sp" android:layout_marginLeft="10dip"></TextView&开发者_运维技巧gt; 
  <ListView android:id="@+id/listView1" android:layout_width="fill_parent" android:layout_height="wrap_content" android:choiceMode="singleChoice" android:layout_marginTop="25dip" android:layout_below="@id/info_tv_id"> 
  </ListView>   
  <RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android" android:layout_width="fill_parent" android:layout_height="wrap_content" android:gravity="bottom" android:layout_alignParentBottom="true" android:id="@+id/relativekeybuttons" android:layout_below="@+id/listView1" android:visibility="gone">"
               <Button android:id="@+id/setasdefault" android:text="@string/default_btn_text" android:layout_marginTop="10dip" 
                android:layout_height="50sp" android:layout_width="75sp">
               </Button>
               <Button android:id="@+id/changepassphrase" android:layout_marginTop="10dip" android:text="@string/passphrase_btn_text" android:layout_width="75sp" android:layout_height="50sp"
                android:layout_toRightOf="@+id/setasdefault"></Button>
               <Button android:id="@+id/rename" android:text="@string/rename_btn_text" android:layout_marginTop="10dip" android:layout_width="75sp"  android:layout_height="50sp"
                android:layout_toRightOf="@+id/changepassphrase"></Button>   
               <Button android:id="@+id/delete" android:layout_width="75sp" android:layout_marginTop="10dip" android:layout_height="50sp" android:text="@string/delete_btn_text"
               android:layout_toRightOf="@+id/rename"></Button>             
  </RelativeLayout>      
</RelativeLayout>

Also, I want the listview to occupy a fixed length in the layout. Eg: atleast 70% of the screen, so that the length of the listview is not dependent on the items in the listview.

Thanks in advance

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Change all units in the xml to dp. Then adjust the controls. Else you'll have to use scrollview as the parent.

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I have some modifications to ur layout. This might work.

<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android" android:layout_width="fill_parent"
    android:layout_height="fill_parent" android:id="@+id/listViewrelativeLayout"
    android:orientation="vertical">
    <TextView android:layout_height="wrap_content" android:layout_width="fill_parent" 
        android:id="@+id/info_tv_id" android:text="Click Me" android:textSize="18sp" 
        android:layout_marginLeft="10dip" android:gravity="center"/>
    <FrameLayout android:layout_width="fill_parent" android:layout_height="0dip"
        android:layout_weight="1.0">
        <ListView android:id="@+id/listView1" android:layout_width="fill_parent" 
            android:layout_height="fill_parent" android:choiceMode="singleChoice" 
            android:layout_below="@id/info_tv_id"/>
        <LinearLayout android:layout_width="fill_parent" android:layout_height="wrap_content"
            android:id="@+id/relativekeybuttons" android:orientation="horizontal" 
            android:layout_gravity="bottom" android:visibility="gone">
            <Button android:layout_width="0dip" android:layout_height="wrap_content" 
                android:layout_weight="1.0" android:text="Default" android:layout_marginLeft="1dip"
                android:textSize="11sp"/>
            <Button android:layout_width="0dip" android:layout_height="wrap_content" 
                android:layout_weight="1.0" android:text="Passphrase"
                android:textSize="11sp"/>
            <Button android:layout_width="0dip" android:layout_height="wrap_content" 
                android:layout_weight="1.0" android:text="Rename"
                android:textSize="11sp"/>
            <Button android:layout_width="0dip" android:layout_height="wrap_content" 
                android:layout_weight="1.0" android:text="Delete" android:layout_marginRight="1dip"
                android:textSize="11sp"/>
        </LinearLayout>  
    </FrameLayout>
</LinearLayout>

Try not to use exact width and heights as it might not work on all phones.