tailieunhanh - Flash Builder 4 and Flex 4 Bible- P13

Flash Builder 4 and Flex 4 Bible- P13: When Macromedia first released Flash MX in 2002, the product was branded as the new way to build Rich Internet Applications (known by the acronym RIA). The term was invented at Macromedia to describe a new class of applications that would offer the benefits of being connected to the Internet, including access to various types of Web-based services, but would solve many of the nagging issues that had been inherent in browser-based applications since the mid-1990s | CHAPTER Using List Controls Most Flex applications are designed for the purpose of presenting and managing data in some form. As a result one of the most popular families of visual controls in the Flex framework includes those known as list controls. A list control is defined as a component that has a dataProvider property that enables you to populate the control with dynamic data. The data provided to a list control can be in the form of either hierarchical or relational data and the type of data you want to present frequently determines which control you use. In addition to being able to display relational or hierarchical data list controls have a common set of properties methods and events that enable the user to select one or more items with mouse and keyboard gestures. The Flex 4 SDK includes both the older MX list controls such as DataGrid AdvancedDataGrid and OlapDataGrid and newer controls based on the new Spark component architecture IN THIS CHAPTER Understanding list controls Providing data to list controls Using dynamic data providers Controlling list item labels Using list control events and properties Handling user data selections Using custom item renderers The List component. This component behaves by default like an HTML select control and displays data items to the user in a list box. After you learn how to use the List control you have most of the information you need to use other such controls. You can populate controls with data listen for events indicating that the user has selected or started to drag data set common styles and so on. It supports the Spark layout architecture so you can display a horizontal or tile layout instead of the default vertical list. The DropDownList and ComboBox components. These components also behave like an HTML select control but use a dropdown list instead of a static list. The ButtonBar component. This component has the same appearance and behavior as an MX ToggleButtonBar presenting a set of ToggleButton .