Android Programming for Beginners - Second Edition

Creating UI widgets from pure Java without XML

We can also create widgets from Java objects that are not a reference to an object in our layout. We can declare, instantiate, and set a widget's attributes, all in code, like this:

Button myButton = new Button();

The preceding code creates a new Button by using new(). The only warning is that the Button has to be part of a layout before it can be shown. So, we could either get a reference to a layout element from our XML layout or create a new one, in code.

If we assume that we have a LinearLayout in our XML with an id property equal to linearLayout1, we could incorporate our Button from the earlier line of code in it, as follows:

// Get a reference to the LinearLayout LinearLayout linearLayout = (LinearLayout) ...