如何布局在Android的各种屏幕支持？

我正在开发使用的GridView图库查看，在小屏幕上我的布局设计，固定得非常好，但大屏幕没有我的设计，在大屏幕有一定的空间的波纹管加载更多图片按钮指fig2，我怎么能解决这个问题问题，我的清单文件中加入这一行的支持不同的屏幕，请给一些样品code对我来说..

i am developing gallery view using gridview,in small screen my layout design fixed very well,but large screen did not my design,In large screen have some spaces bellow "load more picture" button refer fig2,how can i solve this problem,my Manifest file added this lines for support various screen,please give some sample code for me..

<supports-screens android:largeScreens="true"
 android:normalScreens="true" android:smallScreens="true"
 android:anyDensity="false" /> 

和我的XML code

and my xml code

<?xml version="1.0" encoding="utf-8"?>
<merge android:layout_width="wrap_content" android:layout_height="340dp" xmlns:android="http://schemas.android.com/apk/res/android">
 <LinearLayout  android:id="@+id/LinearLayout01"  
 android:layout_width="fill_parent" 
 android:layout_height="335dp" android:orientation="vertical" 
 android:background="@color/black">


 <GridView 
                    android:id="@+id/jr_lookbook_grid" android:layout_width="fill_parent"
                    android:layout_height="335dp" android:numColumns="4"
                    android:verticalSpacing="10dp" android:horizontalSpacing="10dp"
                    android:columnWidth="90dp" android:stretchMode="columnWidth"
                    android:adjustViewBounds="true"
                    android:background="@drawable/shape"  
                    android:gravity="center"  android:layout_weight="1"/>
</LinearLayout>
    <LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:id="@+id/LinearLayout0209_img"
    android:layout_width="fill_parent"
    android:layout_height="wrap_content"
    android:orientation="vertical"
    android:gravity="center"
    android:paddingTop="311dp">
         <Button  android:id="@+id/click"
                android:background="#AA000000" 
                   android:text="Load More Pictures..."
                  android:textColor="@color/white"                  
                   android:layout_width="fill_parent" android:layout_height="30dp"/>
    </LinearLayout>
  <LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:id="@+id/LinearLayout02_img"
    android:layout_width="fill_parent"
    android:layout_height="wrap_content"
    android:orientation="vertical"
    android:layout_gravity="center"
    android:layout_alignParentBottom="true"
    android:background="@color/black"
                android:layout_alignParentLeft="true"> 
   <WebView 
        android:id="@+id/webview"

        android:layout_width="fill_parent"

        android:layout_height="fill_parent"         
        android:scrollbars="none" />
    <ImageView android:id="@+id/ImageView01" 
    android:layout_gravity="center_horizontal"
    android:scaleType="centerInside"
    android:layout_width="wrap_content" 
    android:layout_height="fill_parent"
    android:adjustViewBounds="true">
</ImageView>  
    </LinearLayout>
   <LinearLayout android:id="@+id/LinearLayout02"     android:background="#AA000000" 
         android:layout_width="400px"
        android:layout_height="50dp"
        android:layout_gravity="bottom">
 <Button
    android:id="@+id/back
                android:layout_height="wrap_content"
               android:background="@drawable/back1"
                android:layout_alignParentRight="true"
                android:layout_marginLeft="10dp" /
                 <Button
                  android:background="@drawable/forward5"
                android:id="@+id/next"
                android:layout_width="wrap_content"
                android:layout_height="wrap_content"
                android:gravity="center"
                android:layout_alignParentRight="true"
                android:layout_marginLeft="150dp"/>
                  <Button
                  android:background="@drawable/menushare"
                android:id="@+id/photoshare"
                android:layout_width="wrap_content"
                android:layout_height="wrap_content"
                android:gravity="center"
                android:layout_alignParentRight="true"
                android:layout_marginLeft="20dip" />
</LinearLayout>
</merge>

感谢所有