3.4.3. Changing to a GridLayout
The default layout in a Blank App’s GUI is a RelativeLayout. Here, you’ll change that to a GridLayout. First, right click the TextView in the Outline window, then select Delete to remove it from the GUI. Next, right click the RelativeLayout in the Outline window and select Change Layout.... In the Change Layout dialog, select GridLayout and click OK. The IDE changes the layout and sets its Id to GridLayout1. We changed this to gridLayout using the Id field in the Properties window. By default, the GridLayout’s Orientation property is set to horizontal, indicating that its contents will be laid out row-by-row.
Specifying Two Columns and Default Margins for the GridLayout
Recall that the GUI in Fig. 3.3 consists of two columns. To specify this, select gridLayout in the Outline window, then change its Column Count property to 2 (in the Properties window’s GridLayout group). By default, there are no margins—spaces that separate views—around a GridLayout’s cells. Set the GridLayout’s Use Default Margins property to true to indicate that the GridLayout should place margins around its cells. By default, the GridLayout uses the recommended gap between views (8dp), as specified at