title: GridLayout not showing on my device
body: <p>This is my <code>xml</code> code:</p>
  
  <pre><code>&lt;ScrollView xmlns:android="http://schemas.android.com/apk/res/android"
      xmlns:app="http://schemas.android.com/apk/res-auto"
      xmlns:tools="http://schemas.android.com/tools"
      android:layout_width="match_parent"
      android:layout_height="match_parent"
      android:fillViewport="true"&gt;
  
      &lt;GridLayout
          android:id="@+id/mainGrid"
          android:columnCount="2"
          android:rowCount="3"
          android:alignmentMode="alignMargins"
          android:columnOrderPreserved="false"
          android:layout_width="match_parent"
          android:layout_height="match_parent"
          android:padding="14dp"
          &gt;
          &lt;android.support.v7.widget.CardView
              android:layout_width="0dp"
              android:layout_height="0dp"
              android:layout_columnWeight="1"
              android:layout_rowWeight="1"
              android:layout_marginBottom="16dp"
              android:layout_marginLeft="16dp"
              android:layout_marginRight="16dp"
              app:cardElevation="8dp"
              app:cardCornerRadius="8dp"
              &gt;
  
              &lt;LinearLayout
                  android:layout_gravity="center_horizontal|center_vertical"
                  android:layout_margin="16dp"
                  android:orientation="vertical"
                  android:layout_width="wrap_content"
                  android:layout_height="wrap_content"&gt;
  
                  &lt;ImageView
                      android:src="@drawable/icona_monumenti"
                      android:layout_gravity="center_horizontal"
                      android:layout_width="100dp"
                      android:layout_height="100dp" /&gt;
  
                  &lt;TextView
                      android:text="Me"
                      android:textAlignment="center"
                      android:textSize="18sp"
                      android:textStyle="bold"
                      android:layout_width="wrap_content"
                      android:layout_height="wrap_content" /&gt;
  
              &lt;/LinearLayout&gt;
  
          &lt;/android.support.v7.widget.CardView&gt;
  
          &lt;!-- Column 2 --&gt;
          &lt;android.support.v7.widget.CardView
              android:layout_width="0dp"
              android:layout_height="0dp"
              android:layout_columnWeight="1"
              android:layout_rowWeight="1"
              android:layout_marginBottom="16dp"
              android:layout_marginLeft="16dp"
              android:layout_marginRight="16dp"
              app:cardElevation="8dp"
              app:cardCornerRadius="8dp"
              &gt;
  
              &lt;LinearLayout
                  android:layout_gravity="center_horizontal|center_vertical"
                  android:layout_margin="16dp"
                  android:orientation="vertical"
                  android:layout_width="wrap_content"
                  android:layout_height="wrap_content"&gt;
  
                  &lt;ImageView
                      android:src="@drawable/icona_piatti_tipici"
                      android:layout_gravity="center_horizontal"
                      android:layout_width="100dp"
                      android:layout_height="100dp" /&gt;
  
                  &lt;TextView
                      android:text="Family"
                      android:textAlignment="center"
                      android:textSize="18sp"
                      android:textStyle="bold"
                      android:layout_width="wrap_content"
                      android:layout_height="wrap_content" /&gt;
  
              &lt;/LinearLayout&gt;
  
          &lt;/android.support.v7.widget.CardView&gt;
  
  
          &lt;!-- Row 2 --&gt;
  
          &lt;!-- Column 1 --&gt;
          &lt;android.support.v7.widget.CardView
              android:layout_width="0dp"
              android:layout_height="0dp"
              android:layout_columnWeight="1"
              android:layout_rowWeight="1"
              android:layout_marginBottom="16dp"
              android:layout_marginLeft="16dp"
              android:layout_marginRight="16dp"
              app:cardElevation="8dp"
              app:cardCornerRadius="8dp"
              &gt;
  
              &lt;LinearLayout
                  android:layout_gravity="center_horizontal|center_vertical"
                  android:layout_margin="16dp"
                  android:orientation="vertical"
                  android:layout_width="wrap_content"
                  android:layout_height="wrap_content"&gt;
                  &lt;ImageView
                      android:src="@drawable/icona_storia"
                      android:layout_gravity="center_horizontal"
                      android:layout_width="100dp"
                      android:layout_height="100dp" /&gt;
                  &lt;TextView
                      android:text="Lovely"
                      android:textAlignment="center"
                      android:textSize="18sp"
                      android:textStyle="bold"
                      android:layout_width="wrap_content"
                      android:layout_height="wrap_content" /&gt;
              &lt;/LinearLayout&gt;
          &lt;/android.support.v7.widget.CardView&gt;
          &lt;android.support.v7.widget.CardView
              android:layout_width="0dp"
              android:layout_height="0dp"
              android:layout_columnWeight="1"
              android:layout_rowWeight="1"
              android:layout_marginBottom="16dp"
              android:layout_marginLeft="16dp"
              android:layout_marginRight="16dp"
              app:cardElevation="8dp"
              app:cardCornerRadius="8dp"
              &gt;
              &lt;LinearLayout
                  android:layout_gravity="center_horizontal|center_vertical"
                  android:layout_margin="16dp"
                  android:orientation="vertical"
                  android:layout_width="wrap_content"
                  android:layout_height="wrap_content"&gt;
                  &lt;ImageView
                      android:src="@drawable/icona_informazioni"
                      android:layout_gravity="center_horizontal"
                      android:layout_width="100dp"
                      android:layout_height="100dp" /&gt;
                  &lt;TextView
                      android:text="Team"
                      android:textAlignment="center"
                      android:textSize="18sp"
                      android:textStyle="bold"
                      android:layout_width="wrap_content"
                      android:layout_height="wrap_content" /&gt;
              &lt;/LinearLayout&gt;
          &lt;/android.support.v7.widget.CardView&gt;
      &lt;/GridLayout&gt;
  &lt;/ScrollView&gt;
  </code></pre>
  
  <p>In the preview of my xml file, the <code>GridLayout</code> is visible, but when I run the application, on my phone the <code>GridLayout</code> is not visible.</p>
  
  <p>gradle:
      <i>implementation 'com.android.support:cardview-v7:27.1.1'</i></p>
  
  <p>The code don't give me error or other things, and the same the stack trace</p>
  
  <p>This is the image of my layout:
  <img src="https://i.stack.imgur.com/iwaOV.jpg" alt=""></p>