So far, you have used only default components available in Flex. Though Flex provides a vast variety of simple and complex components as part of its SDK, sometimes you need to create your own. For example, you might want to add some functionality to the existing component, or you might want to build a reusable component.
For example, if you are creating registration and billing information forms, then you might want to show the ComboBox component for selecting the country in the home address section, as well as in the billing address section. Creating two different ComboBox components and adding the country list to it in two places is not a good way forward. Instead, we will create an MXML component that can be reused in the billing address and home address sections.
To create a custom MXML component in Flex Builder, follow these steps:
1. Open the existing Flex project or create a new one.
2. Click and select File | New | MXML Component from the menu bar...