GridLayout Column width

This code is available on pre API21 with support library!

I have a simple piece of code to show 4 buttons in a gridLayout of 2 columns that take 50% of the available space:
perhaps it can help

<GridLayout
    android:id="@+id/grid"
    android:layout_width="match_parent"
    android:layout_height="wrap_content"
    android:columnCount="2"
    >


    <Button
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:text="Button"
        android:layout_gravity="fill"
        android:layout_columnWeight="1"
        />

       <Button
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:text="Button"
        android:layout_gravity="fill"
        android:layout_columnWeight="1"
        />

       <Button
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:text="Button"
        android:layout_gravity="fill"
        android:layout_columnWeight="1"
        />

       <Button
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:text="Button"
        android:layout_gravity="fill"
        android:layout_columnWeight="1"
        />



</GridLayout>

Solution is perhaps this :

android:layout_gravity="fill"
android:layout_columnWeight="1"