title: How Android grid layout set component fill the specified row and column?
body: <p><strong>code:</strong></p>
  
  <pre><code>&lt;GridLayout 
    xmlns:tools="http://schemas.android.com/tools"
    xmlns:android="http://schemas.android.com/apk/res/android"
    android:layout_width="match_parent"  
    android:layout_height="match_parent"   
    android:rowCount="6"  
    android:columnCount="4" &gt;  
  
  &lt;!-- define textbox，Across the four columns --&gt;
  
  &lt;TextView
      android:layout_width="match_parent"
      android:layout_height="wrap_content"
      android:layout_columnSpan="4"
      android:textSize="50sp"
      android:layout_marginLeft="4px"
      android:layout_marginRight="4px"
      android:padding="5px"
      android:layout_gravity="right"
      android:background="#eee"
      android:textColor="#000"
      android:text="test"
      /&gt;
  &lt;!-- define two buttons，Delete and reset --&gt;
  
  &lt;Button
      android:id="@+id/bn1"
      android:layout_columnSpan="2" 
      android:layout_rowSpan="1"
      android:layout_gravity="fill"
      android:text="clear"
       /&gt; 
  
  &lt;Button
      android:id="@+id/bn2"
      android:layout_columnSpan="2" 
      android:layout_rowSpan="1"
      android:layout_gravity="fill"     
      android:text="selete"
      /&gt;
  </code></pre>
  
  <p>The above is the mail.xml code. The results below:</p>
  
  <p><img src="https://i.stack.imgur.com/frHYo.jpg" alt="enter image description here"></p>
  
  <p><em>How to set the two buttons half and half and fill a line?</em> </p>
  
  <p>Thanks in advance!</p>