Using LinearLayout

Another common layout option is the LinearLayout, which arranges the child Views in a single column or single row, depending on the orientation specified. The default orientation (if not specified) is vertical, which aligns the Views in a single column.

The LinearLayout has a key feature not offered in the RelativeLayout—the weight attribute. We can specify a layout_weight parameter when defining a View to allow the View to dynamically size based on the available space. Options include having a View fill all the remaining space (if a View has a higher weight), having multiple Views fit within the given space (if all have the same weight), or spacing the Views proportionally by their weight.

We will create a LinearLayout with three EditText Views to demonstrate how the weight attribute can be used. For this example, we will use three EditText Views—one to enter a To Address parameter, another to enter a Subject, and the third to enter a Message. The To and...