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"

For pre API 21, use support library:

add

compile 'com.android.support:appcompat-v7:23.1.1'
compile 'com.android.support:design:23.1.1'

to your dependencies.

Then in your xml file:

<android.support.v7.widget.GridLayout
                    xmlns:app="http://schemas.android.com/apk/res-auto"
                    android:layout_width="match_parent"
                    android:layout_height="wrap_content"
                    app:columnCount="2"
                    app:orientation="horizontal"
                    app:rowCount="1">

                    <TextView
                        android:text="1"
                        android:textStyle="bold"
                        app:layout_columnWeight="1"
                        />

                    <TextView
                        android:text="2"
                        android:textStyle="bold"
                        app:layout_columnWeight="1" />

</android.support.v7.widget.GridLayout>

Here note the use of "app" prefix and dont forget to add

xmlns:app="http://schemas.android.com/apk/res-auto"

to your xml file