不错的flex学习资料 Creating and Extending Flex2 Components is divided into the following parts: PartDescription Part 1, gCreating Custom Flex Components Describes how to create custom Flex components. Part 2, gCreating MXML Components Describes how to create custom Flex components in MXML. Part 3, gCreating ActionScript Components Describes how to create custom Flex components in ActionScript. Part 4, gCreating Nonvisual Flex Components Describes how to create formatter, validator, and effect components for Flex.