android layout: constant size of bottom view - android-layout

Question

I just started learning Android and got a problem implementing a special layout. I read a lot about layouts and tried everything that crossed my mind, but i couldnt solve it. Probably its very easy and I would be very grateful for your help!
I need a simple layout, having a bigger view at the top and a smaller one at the bottom. The lower view should have a constant size of 150dp, the upper view should be variable in height and fill the rest . It is no problem giving the upper one a constant size and the lower one the rest - but thats not the way i need it...
Thats a simplified screenshot how it should look like:
Screenshot
Thanks a lot!

Answer 1

Here you go:
<?xml version="1.0" encoding="utf-8"?>
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="match_parent"
android:layout_height="match_parent">
<RelativeLayout
android:id="#+id/rl_layout_one"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:background="#android:color/holo_blue_light"
android:layout_above="#+id/rl_layout_two">
<ImageView
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:src="#drawable/ic_launcher"
android:layout_centerInParent="true"/>
</RelativeLayout>
<RelativeLayout
android:id="#+id/rl_layout_two"
android:layout_width="match_parent"
android:layout_height="150dp"
android:background="#android:color/darker_gray"
android:padding="15dp"
android:layout_alignParentBottom="true">
</RelativeLayout>
</RelativeLayout>
This matches your expectation. Howerev, i would like to point out that generally, layout height or width are not specified.It is bad practice. I would suggest another option, using LinearLayouts with weights, find the code below.
<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:orientation="vertical"
android:weightSum="1">
<RelativeLayout
android:id="#+id/rl_layout_one"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:background="#android:color/holo_blue_light"
android:layout_weight="0.4">
</RelativeLayout>
<RelativeLayout
android:id="#+id/rl_layout_two"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:background="#android:color/darker_gray"
android:padding="15dp"
android:layout_weight="0.6">
</RelativeLayout>
</LinearLayout>
Hope these help.
EDIT 1:
Check the 1st solution, it was missing the layout_above attribute, that is why it took the whole screen space and centered the image according to the whole screen space. Now, it will not, since layout one is above layout two, it will center your image according to layout one.