flex 3 java_Flex4相对于Flex3的变化 - 唐@朝 - JavaEye技术网站

customizations much more straightforward. Here is a table showing Flex 3 Halo components and their Flex 4 beta Spark counterparts:

Flex 3 Halo Component

Flex 4 beta Spark Component

mx.controls.Button

sparkponents.Button

mx.controls.ButtonBar

sparkponents.ButtonBar

mx.controls.CheckBox

sparkponents.CheckBox

mx.controls.ComboBox

sparkponents.DropDownList (w/o editability)

mx.controls.HorizontalList

sparkponents.List (with a HorizontalLayout)

mx.controls.HRule

spark.primitives.Line

mx.controls.HScrollBar

sparkponents.HScrollBar

mx.controls.HSlider

sparkponents.HSlider

mx.controls.Image

spark.primitives.BitmapImage

mx.controls.LinkBar

sparkponents.ButtonBar (with a custom skin)

mx.controls.LinkButton

sparkponents.Button (with a custom skin)

mx.controls.List

sparkponents.List

mx.controls.NumericStepper

sparkponents.NumericStepper

mx.controls.RadioButton

sparkponents.RadioButton

mx.controls.RadioButtonGroup

sparkponents.RadioButtonGroup

mx.controls.TextArea

sparkponents.TextArea

mx.controls.TextInput

sparkponents.TextInput

mx.controls.TileList

sparkponents.List (with a TileLayout)

mx.controls.ToggleButtonBar

sparkponents.ButtonBar

mx.controls.VideoDisplay

sparkponents.VideoPlayer

mx.controls.VRule

spark.primitives.Line

mx.controls.VScrollBar

sparkponents.VScrollBar

mx.controls.VSlider

sparkponents.VSlider

mx.core.Application

sparkponents.Application

mx.core.Window

sparkponents.Window

mx.core.WindowedApplication

sparkponents.WindowedApplication

mx.containers.Canvas

sparkponents.Group

mx.containers.HBox

sparkponents.HGroup

mx.containers.Panel

sparkponents.Panel

mx.containers.Tile

sparkponents.Group (with a TileLayout)

mx.containers.VBox

sparkponents.VGroup

Adobe encourages you to use Halo components and containers along with Spark components. Because Adobe continues to build components atop the same base class (UIComponent), there should be full interoperability between Spark and Halo. Here is a table of the components and containers that do not currently have direct Spark equivalent classes.

Flex 3 classes with no direct Flex 4 beta counterpart

mx.controls.Alert

mx.controls.ColorPicker

mx.controls.DataGrid

mx.controls.DateChooser

mx.controls.DateField

mx.controls.Menu

mx.controls.MenuBar

mx.controls.PopUpButton

mx.controls.PopUpMenuButton

mx.controls.ProgressBar

mx.controls.RichTextEditor

mx.controls.TabBar

mx.controls.Tree

mx.containers.Accordion

mx.containers.ApplicationControlBar

mx.containers.ControlBar

mx.containers.DividedBox

mx.containers.Form

mx.containers.Grid

mx.containers.TabNavigator

mx.containers.TitleWindow

mx.containers.ViewStack

Changes in states syntax

Flex 4 beta has promoted the states functionality to a full MXML language feature. As a result, you will likely find states to be much more flexible and direct. The new states syntax is more inline, allowing state-specific changes to be specified in context. Here are the key differences in the Flex 4 beta syntax:

Only states are defined within the states array.

In the new states syntax, you cannot use de>AddChildde> and de>RemoveChildde>. Instead, you define a component's role in a particular state on the component itself using the de>includeInde> and de>excludeFromde> attributes.

In the following Flex 3 example, states are used to include a Button and remove a TextInput only when the de>currentStatede> of the document is de>submitStatede>. This approach can get very verbose with more complex states.

Here is the simpler Flex 4 beta code using de>includeInde> and de>excludeFromde>.

de>SetPropertyde>, de>SetStylede>, and de>SetEventHandlerde> have been replaced by a new dot syntax, which allows you to qualify MXML attribute values with a specific state identifier.

In the following Flex 3 example, the code defines a property, style, and event for a Button in de>submitStatede>.

de>handler="emptyDocument()" />

In Flex 4 beta, the code looks like this:

click.submitState="trace('done')" click.clearState="emptyDocument()"

label.clearState="clear" textDecoration.clearState="none"/>

A component can no longer be in an undefined or null state. By default, the first declared state is the initial state of a component.

The new syntax is available when a document uses the MXML 2009 language namespace. You cannot mix the legacy syntax and the new states syntax. The old syntax is available only in the MXML 2006 namespace.

Additionally, each component now supports a set of states defined in its skin class, which makes it simpler to apply visual changes depending on the state of a component. For example, if you look at the skin for the Spark Button, you will find the following states defined:

The ButtonSkin class defines what happens visually to a Spark Button in each one of these states.

This is only a brief introduction to the new Flex 4 beta states syntax. Visit the Enhanced States Syntax Spec to find more details.